PART NO.
TO4HA-E-00
ZW 310
WHEEL LOADER
Technical Manual
Operational Principle
TECHNICAL MANUAL
Wheel Loader
OPERATIONAL PRINCIPLE
URL:http://www.hitachi-c-m.com
310
Service Manual consists of the following separate Part No;
Technical Manual (Operational Principle)
: Vol. No. TO4HA-E
Technical Manual (Troubleshooting)
: Vol. No. TT4HA-E
Workshop Manual
: Vol. No. W4HA-E
PRINTED IN SINGAPORE (YS) 2006.03
TO4HA-E-00 ZW.p65
1
1/3/06, 11:24
INTRODUCTION
TO THE READER
• This manual is written for an experienced technician
to provide technical information needed to maintain
and repair this machine.
• Be sure to thoroughly read this manual for correct product information and service procedures.
• If you have any questions or comments, at if you
found any errors regarding the contents of this
manual, please contact using “Service Manual
Revision Request Form” at the end of this manual.
(Note: Do not tear off the form. Copy it for usage.):
Publications Marketing & Product Support
Hitachi Construction Machinery Co. Ltd.
TEL: 81-29-832-7084
FAX: 81-29-831-1162
ADDITIONAL REFERENCES
• Please refer to the materials listed below in addition
to this manual.
• The Operator’s Manual
• The Parts Catalog
• The Engine Manual
• Parts Catalog of the Engine
• Hitachi Training Material
MANUAL COMPOSITION
• This manual consists of three portions: the Technical Manual (Operational Principle), the Technical
Manual (Troubleshooting) and the Workshop Manual.
• Information included in the Technical Manual
(Operational Principle):
technical information needed for redelivery and
delivery, operation and activation of all devices
and systems.
• Information included in the Technical Manual
(Troubleshooting):
technical information needed for operational performance tests, and troubleshooting procedures.
• Information included in the Workshop Manual:
technical information needed for maintenance
and repair of the machine, tools and devices
needed for maintenance and repair, maintenance
standards, and removal/installation and assemble/disassemble procedures.
PAGE NUMBER
• Each page has a number, located on the center
lower part of the page, and each number contains
the following information:
Example : T 1-3-5
Consecutive Page Number for Each Group
Group Number
Section Number
T: Technical Manual
W: Workshop Manual
IN-01
INTRODUCTION
SAFETY ALERT SYMBOL AND HEADLINE
NOTATIONS
In this manual, the following safety alert symbol and
signal words are used to alert the reader to the
potential for personal injury of machine damage.
This is the safety alert symbol. When you see this
symbol, be alert to the potential for personal injury.
Never fail to follow the safety instructions prescribed
along with the safety alert symbol.
The safety alert symbol is also used to draw attention
to component/part weights.
To avoid injury and damage, be sure to use appropriate lifting techniques and equipment when lifting
heavy parts.
•
CAUTION:
Indicated potentially hazardous situation which
could, if not avoided, result in personal injury or
death.
• IMPORTANT:
Indicates a situation which, if not conformed to the
instructions, could result in damage to the machine.
•
NOTE:
Indicates supplementary technical information or
know-how.
UNITS USED
• SI Units (International System of Units) are used in
Example : 24.5 MPa (250 kgf/cm2, 3560 psi)
this manual.
MKSA system units and English units are also
indicated in parenthheses just behind SI units.
Quantity
Length
Volume
Weight
Force
Torque
To Convert
From
mm
mm
L
L
m3
kg
N
N
N⋅m
N⋅m
Into
Multiply By
in
ft
US gal
US qt
yd3
lb
kgf
lbf
kgf⋅m
lbf⋅ft
0.03937
0.003281
0.2642
1.057
1.308
2.205
0.10197
0.2248
1.0197
0.7375
A table for conversion from SI units to other system
units is shown below for reference purposees.
Quantity
Pressure
Power
Temperature
Velocity
Flow rate
IN-02
To Convert
From
MPa
MPa
kW
kW
°C
km/h
min-1
L/min
mL/rev
Into
Multiply By
kgf/cm2
psi
PS
HP
°F
mph
rpm
US gpm
cc/rev
10.197
145.0
1.360
1.341
°C×1.8+32
0.6214
1.0
0.2642
1.0
SECTION AND GROUP
CONTENTS
SECTION 1 GENERAL
Group 1 Specification
Group 2 Component Layout
Group 3 Component Specifications
SECTION 2 SYSTEM
TECHNICAL MANUAL
(Operational Principle)
Group 1 Control System
Group 2 ECM System
Group 3 Hydraulic System
Group 4 Electrical System
SECTION 3 COMPONENT OPERATION
All information, illustrations and specifications in this manual are based on
the latest product information available
at the time of publication. The right is
reserved to make changes at any time
without notice.
COPYRIGHT (C) 2005
Group 1 Pump Device
Group 2 Control Valve
Group 3 Hydraulic Fan Motor
Group 4 Steering Pilot Valve
Group 5 Steering Valve
Group 6 Pilot Valve
Group 7 Charging Block
Group 8 Ride Control Valve
Group 9 Drive Unit
Group 10 Axle
Group 11 Brake Valve
Group 12 Others
TECHNICAL MANUAL (Troubleshooting)
SECTION 4 OPERATIONAL PERFORMANCE TEST
Group 1 Introduction
Group 2 Standard
Group 3 Engine Test
Group 4 Wheel Loader Test
Group 5 Component Test
Group 6 Adjustment
SECTION 5 TROUBLESHOOTING
Group 1 Diagnosing Procedure
Group 2 Dr-ZX
Group 3 e-Wheel
Group 4 Component Layout
Group 5 Troubleshooting A
Group 6 Troubleshooting B
Group 7 Troubleshooting C
Group 8 Electrical System Inspection
Hitachi Construction Machinery Co., Ltd.
Tokyo, Japan
All rights reserved
←これ以下
記載しない
WORKSHOP MANUAL
SECTION 1 GENERAL INFORMATION
Group 1 Precautions for Disassembling and Assembling
Group 2 Tightening Torque
Group 3 Painting
Group 4 Bleeding Air from Hydraulic Oil Tank
SECTION 2 BASE MACHINE (UPPER
STRUCTURE)
Group 1 Cab
Group 2 Counterweight
Group 3 Frame
Group 4 Pump Device
Group 5 Control Valve
Group 6 Pilot Valve
Group 7 Ride Control Valve
Group 8 Pilot Shutoff Valve
Group 9 Hydraulic Fan Motor
SECTION 3 BASE MACHINE (TRAVEL
SYSTEM)
Group 1 Tire
Group 2 Drive Unit
Group 3 Axle
Group 4 Propeller Shaft
Group 5 Brake Valve
Group 6 Charging Block
Group 7 Steering Pilot Valve
Group 8 Steering Valve
Group 9 Steering Cylinder
Group 10 Emergency Steering Pump Unit
(Optional)
SECTION 4 FRONT ATTACHMENT
Group 1 Front Attachment
Group 2 Cylinder
SECTION 5 ENGINE
SECTION 1
GENERAL
―CONTENTS―
Group 1 Specifications
Group 3 Component Specifications
Specifications ........................................... T1-1-1
Engine ...................................................... T1-3-1
Engine Accessories .................................. T1-3-5
Group 2 Component Layout
Main Component Layout........................... T1-2-1
Electrical Component Layout.................... T1-2-4
Hydraulic Component ............................... T1-3-6
Electrical Component.............................. T1-3-10
(Overview)
Electrical System (Cab) ............................ T1-2-5
Electrical System .................................... T1-2-6
(Controller and Relays)
Electrical System (Right Console) ............ T1-2-7
Electrical System (Monitor and Switchs)... T1-2-8
Monitor Panel ........................................... T1-2-9
Engine and Fan Pump ............................ T1-2-10
Pump Device and Drive Unit....................T1-2-11
Control Valve .......................................... T1-2-12
Ride Control Valve,Charging Block
and Fan Motor ................................... T1-2-13
Steering Valve and Emergency Steering
Pump (Optional) .................................. T1-2-14
4HAT-1-1
(Blank)
4HAT-1-2
GENERAL / Specification
SPECIFICATIONS
M4GB-12-002
−
Type
3
3
ZW310 (EU)
ZW310 (Standard)
Bucket Capacity (Heaped)
m (yd )
4.2 (BOC)
4.0 (BOC)
Operating Weight
kg(lb)
23270
22290
Static Tipping Load (Full Turn)
kg(lb)
16600
15000
Rated Loading Weight
kg(lb)
7200
6400
−
OM460LA
216.0 kW/2000 rpm
(293.7 PS/2000 rpm)
OM460LA
216.0 kW/2000 rpm
(293.7 PS/2000 rpm)
A: Overall Length
mm(ft.in)
8840
8760
B: Overall Width (Bucket)
mm(ft.in)
2980
3150
C: Overall Height
mm(ft.in)
3460
3465
D: Wheel Base
mm(ft.in)
3450
3450
E: Tread
mm(ft.in)
2230
2300
F: Ground Clearance
mm(ft.in)
480
485
G: Height to Bucket Hinge Pin, Fully Raised
mm(ft.in)
4390
4395
H: Dumping Clearance 45 Degree, Full Height
mm(ft.in)
3070
3130
I:
mm(ft.in)
1240
1180
R1: Turning Radius (Centerline of Outside Tire)
mm(ft.in)
5860
5900
R2: Loader Clearance Circle, Bucket in Carry Position
mm(ft.in)
6920
6970
Maximum Travel Speed (Forward/Reverse)
km/h(mph)
35.5/35.5
34.5/34.5
Number of Travel Shift (Forward/Reverse)
−
4/4
4/4
Degree(%)
40
40
−
26.5R25
26.5R-25-16PR
Engine
Dumping Reach, 45 Degree Dump, Full Height
Articulation Angle (Left/Right)
Tire Size
T1-1-1
GENERAL / Specification
(Blank)
T1-1-2
GENERAL / Component Layout
MAIN COMPONENT LAYOUT (OVERVIEW)
1
2
3
4
5
6
12
7
11
10
9
T4HA-01-02-008
8
1 - Bucket
2 - Bell Crank
4 - Head Light
5 - Front Working Light
3 - Bucket Cylinder
6 - Rear Working Light (Optional)
7 - Rear Working Light
8 - Rear Combination Light
(Turn Signal, Hazard Light
Clearance Light, Brake
Light and Reverse Light)
9 - Turn Signal, Hazard Light
and Clearance Light
T1-2-1
10 - Lift Arm Cylinder
11 - Lift Arm
12 - Bucket Link
GENERAL / Component Layout
MAIN COMPONENT LAYOUT (UPPERSTRUCTURE)
1
2
3
4
5
22
21
20
19
18
17
15
16
6
15
7
8
9
14
13
12
11
10
T4HA-01-02-009
123456-
Charging Block
Pilot Valve
Brake Valve
Steering Pilot Valve
Steering Valve
Control Valve
7 - Stop Valve
8 - Pilot Shutoff Valve
9 - Pilot Filter
10 - Engine
11 - Fuel Filter
12 - Torque Converter Cooler
13 - Fuel Tank
14 - Oil Cooler
15 - Radiator
16 - Fan Motor
17 - Inter Cooler
18 - Reserve Tank
T1-2-2
19 - Engine Oil Filter
20 - Muffler
21 - Air Cleaner
22 - Hydraulic Tank
GENERAL / Component Layout
MAIN COMPONENT LAYOUT (TRAVEL SYSTEM)
1
2
3
4
5
6
9
8
7
T4HA-01-02-010
1 - Front Axle
2 - Propeller Shaft (Front)
3 - Steering Cylinder
45-
Pump Device
Transmission
6 - Rear Axle
7 - Propeller Shaft (Rear)
T1-2-3
8 - Steering Accumulator
9 - Brake Pressure Sensor
GENERAL / Component Layout
ELECTRIC COMPONENT LAYOUT (OVERVIEW)
Cab
(Refer to T1-2-5)
12
2
1
13
Engine and Fan Pump
(Refer to T1-2-10)
11
10
3
4
5
7
9
Pump Device
(Refer to T1-2-11)
Drive Unit
(Refer to T1-2-11)
6
8
T4HA-01-02-011
1 - Hydraulic Oil Level Switch
5-
Boost Pressure Sensor
2 - Air Filter Restriction Switch
6-
Fuel Level Sensor
3 - Reverse Buzzer
7-
Hydraulic Oil Temperature
Sensor
8 - Emergency Steering Pump
Delivery Pressure Switch
9 - Lift Arm Angle Sensor
(Optional)
10 - Bucket Proximity Switch
4 - Battery
T1-2-4
11 - Lift Arm Proximity Switch
12 - Implement Pressure Sensor
13 - Out Side Temperature
Sensor
GENERAL / Component Layout
ELECTRICAL SYSTEM (CAB)
1
2
3
Monitor and Switches
(Refer to T1-2-8)
4
Right Consol
(Refer to T1-2-7)
6
5
Controller and Relays
(Refer to T1-2-6)
T4GB-01-02-006
1 - Radio
2 - Auxiliary Switch Panel
(Optional)
3 - Speaker
4 - Rear Wiper Motor
5 - Brake Lamp Switch
T1-2-5
6 - Front Wiper Motor
GENERAL / Component Layout
Controller and Relays
6
7
T4GB-01-02-006
11
5
4
1
15
16
17
18
19
2
20
21
22
23
24
12
8
13
9
14
10
3
25
26
27
28
29
30
31
32
33
34
T4GC-01-02-021
1-
Flasher Relay
2-
10 - Front Window Heater Relay
Option Controller
(Optional)
3 - ECM1
11 - Neutral Relay
12 - Rear Window Heater Relay
4-
MCF
13 - Wiper Relay (Left)
5-
ICF
14 - Wiper Relay (Right)
6-
Dr.ZX Connector
15 - Reverse Light Relay (A-R5)
7-
Fuse Box
16 - Brake Light Relay (A-R4)
89-
Fog Light Relay (Optional)
Auxiliary
17 - High Beam Relay (A-R3)
18 - Head Light Relay (Right)
(A-R2)
T4GB-01-02-022
19 - Head Light Relay (Left)
(A-R1)
20 - Emergency Steering Relay
(A-R10)
21 - Hone Relay (A-R9)
22 - Turn Signal Relay (Right)
(A-R8)
23 - Working Light Relay (Rear)
(A-R7)
24 - Working Light Relay (Front)
(A-R8)
25 - Front Wiper Relay (B-R5)
26 - Neutral Relay (B-R4)
T1-2-6
27 - Load Dump Relay (B-R3)
28 - Parking Brake Relay
(B-R2)
29 - Parking Brake Relay
(B-R1)
30 - Fuel Pump Relay (B-R10)
31 - Main Relay (B-R9)
32 - Rear Washer Relay (B-R8)
33 - Turn Signal Relay (Left)
(B-R7)
34 - Rear Wiper Relay (B-R6)
GENERAL / Component Layout
Right Console
T4GB-01-02-006
2
3
4
6
5
7
1
8
9
10
18
17
16
15
14
13
12
T4GB-01-02-023
11
1 - Down Shift Switch
2 - Bucket Operation Lever
3 - Lift Arm Control Lever
4 - Forward/Reverse Switch
5 - Hone Switch
6 - Auxiliary Control Lever (Optional)
7 - Quick Coupler Switch (Optional)
8 - Lift Arm Auto Leveler Downward
Set Switch (Optional)
9 - Lift Arm Auto Leveler Upward
Set Switch (Optional)
10 - Front Control Lock Lever
11 - Emergency Steering Check
Switch
12 - Fan Reverse Switch
13 - Fog Light Switch (Optional)
15 - Forward/Reverse Selector
Switch
16 - Cigar Lighter
17 - Up-shift/Down-shift Switch
14 - Ride Control Switch (Optional)
18 - Hold Switch
T1-2-7
GENERAL / Component Layout
Monitor and Switches
1
2
T4GB-01-02-006
14
3
13
12
4
5
11
6
7
10
9
8
1 - Monitor Panel
(Refer to T1-2-9)
2 - Driving Mode Switch
3 - Turn Signal Lever/Head Light
Switch/Dimmer Switch
4 - Parking Brake Switch
T4GB-01-02-024
5 - Work Mode Selector Switch
9 - Front Wiper Switch
12 - Rear Wiper Switch
6 - Clutch Cat Position Switch
10 - Forward/Reverse Lever
and Shift Switch
11 - Air Conditioner Switch
Panel
13 - Working Light Switch
7 - Key Switch
8 - Steering Column Tilt
/Telescopic Lever
T1-2-8
14 - Hazard Light Switch
GENERAL / Component Layout
Monitor Panel
1
2
3
4
5
6
7
8
9
10
11
34
12
33
13
14
32
15
31
T4GB-01-02-001
30
29
28
1 - Coolant Temperature
Gauge
2 - Transmission Oil Temperature Gauge
3 - Turn Signal Indicator
(Left)
4 - High Beam Indicator
5 - Working Light Indicator
6 - Turn Signal Indicator
(Right)
7 - Monitor Display
8 - Stop Indicator
9 - Service Indicator
27
26
25
24 23
22
10 - Parking Brake Indicator
21
20
19
18
11 - Clearance Light Indicator
19 - Lever Steering Indicator (Optional)
20 - Monitor Mode Selector
12 - Fuel Gauge
21 - Glow Signal
13 - Brake Low Oil Pressure
Indicator
14 - Brake Low Oil Level Indicator
15 - Emergency Steering Indicator (Optional)
16 - Low Steering Oil Pressure
Indicator
17 - Seat Belt Indicator
22 - Monitor Display Selector (Up)
23 - Maintenance Indicator
24 - Monitor Display selector
(Down)
25 - Forward/Reverse Switch Indicator
26 - Water Separator Indicator
18 - Discharge Warning Indicator
T1-2-9
17
16
27 - Engine Warning Indicator
28 - Overheat Indicator
29 - Engine Low Oil Pressure
Indicator
30 - Air Filter Restriction Indicator
31 - Transmission Warning Indicator
32 - Transmission Oil Filter Restriction Indicator
33 - Hydraulic Oil Temperature
Indicator
34 - Transmission Oil Temperature Indicator
GENERAL / Component Layout
ENGINE AND FAN PUMP
1
2
3
4
5
6
7
8
View A
13
15
12
A
14
11
10
9
T4HA-01-02-007
1 - Engine Oil Filter
5 - Fuel Filter
9 - ECM2
2 - Engine Oil Combination
Sensor (Temperature and
Pressure)
3 - Alternator
6 - Start and Stop Switch
10 - Fuel Cooler (ECM2 Cooler)
13 - Fan Pump (Not shown in
the image)
14 - Top Dead Center Sensor
7 - Inlet Air Combination Sensor (Temperature and
Pressure)
8 - Coolant Temperature Sensor
11 - Low Pressure Fuel Pump
15 - Crank Revolution Sensor
4 - Starter
12 - Fuel Temperature Sensor
T1-2-10
GENERAL / Component Layout
PUMP DEVICE
1
2
3
6
5
T4GB-01-02-009
4
DRIVE UNIT
7
21
8
9
13
14
15
16
17
18
20
12
19
11
10
T4GC-01-02-001
1 - Main Pump
7-
2 - Regulator
Torque Converter Input
Speed Sensor
8 - Air Breather
3 - Priority Valve
9-
4 - Pump Delivery Pressure
Switch
5 - Pilot Pump
10 - Vehicle Speed
Sensor
11 - Transmission Output
Speed Sensor
Charge Pump
12 - Transmission Middle Shaft
Sensor
13 - Forward Clutch Solenoid
Valve
14 - Reverse Clutch Solenoid
Valve
15 - 1st Clutch Solenoid Valve
16 - 2nd Clutch Solenoid Valve
6 - Steering Relief Valve
T1-2-11
17 - 3rd Clutch Solenoid Valve
18 - 4th Clutch Solenoid Valve
19 - Transmission Control Valve
20 - Parking Brake Pressure
Switch
21 - Regulator Valve
GENERAL / Component Layout
CONTROL VALVE
5
1
4
3
2
T4GB-03-02-002
1 - Over Load Relief Valve
(Lift Arm: Bottom)
2 - Over Load Relief Valve
(Bucket: Bottom)
3 - Over Load Relief Valve
(Bucket: Rod)
4 - Make-up Valve
(Lift Arm: Rod)
T1-2-12
5 - Main Relief Valve
GENERAL / Component Layout
RIDE CONTROL VALVE (OPTIONAL)
1
2
CHARGING BLOCK
3
4
5
6
10
T4GB-01-02-014
9
8
7
T4GB-01-02-013
FAN MOTOR
10
11
12
T4GB-01-02-012
1 - Overload Relief Valve
2 - Ride Control Solenoid
Valve
3 - Ride Control Accumulator
5 - Service Brake Accumulator
(Front)
6 - Service Brake Accumulator
(Rear)
7 - Relief Valve
89-
Pilot Relief Valve
Pump Torque Control Solenoid Valve
10 - Parking Brake Solenoid
Valve
4 - Pilot Accumulator
T1-2-13
11 - Reverse Control Solenoid
Valve
12 - Relief Valve
13 - Flow Control Solenoid
Valve
GENERAL / Component Layout
STEERING VALVE
1
2
T4GB-01-02-020
EMERGENCY STEERING PUMP
3
4
5
6
T4GB-01-02-010
1 - Overload Relief Valve
2 - Overload Relief Valve
3 - Electric Motor
4 - Gear Pump
5 - Check Valve
T1-2-14
6-
Relief Valve
GENERAL / Component Specifications
ENGINE
Manufacturer ............................................ Daimler Chrysler
Model........................................................ OM460LA
Type.......................................................... Diesel, 4 Cycle, Water Cooled, Over Head Valve, Inline,
Direct Injection, Turbo Charged
Cyl. NO. - Bore×Stroke............................. 6-128 mm×166 mm (5.04 in×6.54 in)
Piston Displacement................................. 12816 cm3 (782.03 in3)
Rated Output ............................................ 216 kW/2000 min-1 (294±4 PS/2000 rpm)
Max. Output.............................................. 220 kW/1800 min-1 (299 PS/1800 rpm)
Compression Ratio................................... 17.5
Dry Weight................................................ 1040 kg (2293 lb)
Firing Order .............................................. 1-5-3-6-2-4
Rotation Direction..................................... Clock Wise (Viewed from fan side)
COOLING SYSTEM
Cooling Fan .............................................. Diameter 850 mm (33.47 in),
6 Blades (N6G-Type Blade, Steel Center), Draw-in Type
Thermostat ............................................... Cracking Temperature at Atmospheric Pressure:
83 °C (181 °F)
Full Open (Stroke: 8 mm (0.32 in) or more) Temperature:
95 °C (203 °F)
Fan Pump................................................. Gear Pump
LUBRICATION SYSTEM
Lubrication Pump Type............................. Gear Pump
Oil Filter .................................................... Full-Flow Paper Element Type with Bypass
Oil Cooler ................................................. Water Cooled Integral Type
STARTING SYSTEM
Motor ........................................................ Magnetic Pinion Shift Reduction Type
Voltage/Output.......................................... 24 V⋅7 kW
PREHEAT SYSTEM
Preheating Method ................................... Intake Air Heater
T1-3-1
GENERAL / Component Specifications
ENGINE STOP SYSTEM
Stop Method ............................................. Fuel Shut Off (Electrically Controlled)
ALTERNATOR
Type.......................................................... Regulator Integrated AC Type
Voltage/Output.......................................... 24 V⋅80 A (Brush less)
SUPERCHARGING SYSTEM
Model........................................................ S410
Type.......................................................... Exhaust Turbocharger Type
FUEL SYSTEM
Type.......................................................... Unit Injector Type
Governor .................................................. Electrically Controlled
Injection Nozzle ........................................ Electric Multi Hole Injector
T1-3-2
GENERAL / Component Specifications
PERFORMANCE
IMPORTANT: This list shows design specifications, which are not servicing standards.
Fuel Consumption Ratio ......................... 205 g/kW⋅h (151 g/PS⋅h) @ 220 kW/
1800 min-1(299 PS/1800 rpm)
Maximum Output Torque .......................... 1400 N⋅m (143 kgf⋅m) @ at approx 1300 min-1 (rpm)
Valve Clearance (Inlet/Exhaust)............... 0.4/0.6 mm (0.016/0.024 in) (when cool)
No load Speed.......................................... Slow: (at Full Load: 800 min-1 (rpm))
Fast: (at Full Load: 2160 min-1 (rpm))
T1-3-3
GENERAL / Component Specifications
Engine Performance Curve (OM460LA)
Test Condition: EU Standard 80/1269/EEC
Output
(kW)
Torque
(N⋅m)
Fuel
Consumption
Ratio
(g/kW⋅h)
Engine Speed min-1 (rpm)
T1-3-4
T4HA-01-03-001
GENERAL / Component Specifications
ENGINE ACCESSORIES
RADIATOR ASSEMBLY
Type.......................................................... Radiator and Oil Cooler Tandem Type Assembly
Inter Cooler and Torque Converter Cooler Tandem Type Assembly
Radiator
Capacity.................................................... 22.8 L (6 US gal)
Air-Tight Test Pressure ............................. 100 kPa (1.0 kgf/cm2, 14.5 psi)
Cap Opening Pressure.............................
−
Oil Cooler
4 L (1.1 US gal)
1500 kPa (15 kgf/cm2, 217 psi))
−
Intercooler
Capacity.................................................. 15 L (4 US gal)
Torque Converter Cooler
2.8 L (Oil)(0.74 US gal)
5 L (Coolant) (1.32 US gal)
1500 kPa (15 kgf/cm2, 217 psi)
−
Air-Tight Test Pressure ............................. 245 kPa (2.5 kgf/cm2, 36 psi)
Cap Opening Pressure.............................
−
BATTERY
Voltage...................................................... 12 V
Capacity.................................................... 120 Ah
HYDRAULIC FAN PUMP
Model........................................................ SGP1A27D2H1-R234
Type.......................................................... Fixed Displacement Type Gear Pump
Maximum Flow (Theoretical Value).......... 60 L/min (15.85 US gpm)
HYDRAULIC FAN MOTOR
Relief Set Pressure .................................. 20.6 MPa (210 kgf/cm2) @ 5 L/min (1.32 US gpm)
SOLENOID VALVE
Function.................................................... Fan Motor Reverse Control
Fan Motor Speed Control
T1-3-5
GENERAL / Component Specifications
HYDRAULIC COMPONENT
MAIN PUMP
Type.......................................................... Bent Axis Type Variable Displacement Axial Plunger Pump
Maximum Flow (Theoretical Value).......... 340 L/min (80 US gum)
REGULATOR
Type.......................................................... Hydraulic Pressure Operated Type
PRIORITY VALVE
Relief Set Pressure .................................. 29.4 MPa (300 kgf/cm2) @ 90 L/min (23.8 US gpm) (ZW250)
PILOT PUMP
Model........................................................ HY/ZFS11/16.8
Type.......................................................... Fixed Displacement Type Gear Pump
Maximum Flow (Theoretical Value).......... 33 L/min (8.7 US gpm)
CONTROL VALVE
Type.......................................................... Pilot Pressure Operated Type (2 Spools)
Main Relief Set Pressure.......................... 29.4 MPa (300 kgf/cm2) @ 290 L/min (77 US gpm)
Overload Relief Set Pressure................... 36.8 MPa (375 kgf/cm2) @ 50 L/min (13 US gpm)
(Lift Arm)
32.5 MPa (330 kgf/cm2) @ 50 L/min (13 US gpm)
(Bucket Tilt, Bucket Dump)
RIDE CONTROL VALVE
Type.......................................................... Pilot Pressure Operated Type
Overload Relief Set Pressure................... 39.2 MPa (400 kgf/cm2) @ 50 L/min (13 US gpm)
Charge Cut Pressure................................ 11.3 MPa (115 kgf/cm2)
RIDE CONTROL ACCUMULATOR
Capacity.................................................... 5 L (305 in3)
Charging Pressure ................................... 2.9 MPa (30 kgf/cm2)
T1-3-6
GENERAL / Component Specifications
CHARGING BLOCK
Charging Pressure ................................... Cut In Pressure: 11.8 MPa (120 kgf/cm2)
Cut Out Pressure: 14.7 MPa (150 kgf/cm2)
Pilot Relief Valve Set Pressure................. 3.7 MPa (38 kgf/cm2) @ 40 L/min (10.6 US gpm)
SOLENOID VALVE (For Charging Block)
Function.................................................... • Main Pump Torque Control
• Parking Brake
SERVICE BRAKE ACCUMULATOR
Capacity.................................................... 1.4 L (85.4 in3)
Charging Pressure ................................... 4.4 MPa (45 kgf/cm2)
PILOT ACCUMULATOR
Capacity.................................................... 0.75 L (45.8 in3)
Charging Pressure ................................... 2.0 MPa (20 kgf/cm2)
PILOT SHUT OFF VALVE
Type.......................................................... Rotary Type
STEERING VALVE
Type.......................................................... Flow Amp Type
Over Load Relief Set Pressure ................ 34.3 MPa (350 kgf/cm2) @50 L/min (13 US gpm)
STEERING PILOT VALVE
Type.......................................................... Orbitroll Type
Gerotor Capacity ...................................... 96 cm3/rev (5.9 in3/rev)
STEERING ACCUMULATORｖ
Capacity.................................................... 0.2 L (12 in3)
Charging Pressure ................................... 8 MPa (82 kgf/cm2)
BRAKE VALVE
Brake Pressure......................................... 3.9 MPa (40 kgf/cm2)
T1-3-7
GENERAL / Component Specifications
• Travel System
TRANSMISSION
Type.......................................................... TCM TM310
Gear Ratio ................................................ Forward 1st : 3.507
Forward 2nd : 2.067
Forward 3rd : 1.071
Forward 4th : 0.631
Reverse 1st : 3.507
Reverse 2nd : 2.067
Reverse 3rd : 1.071
Reverse 4th : 0.631
Parking Brake Release Pressure ............. 2.7 MPa (28 kgf/cm2)
STANDARD AXLE (FRONT/REAR)
Model........................................................ Two Stage Transmission
Brake Type ............................................... Wet Multiplate Disk Brake
Brake Pressure......................................... 3.92 MPa (40 kgf/cm2)
Final Reduction Gear Ratio...................... 27.484
STANDARD PROPELLER SHAFT
Type.......................................................... Cruciform Joint Type
Dimension between Pins.......................... Front : 1615 mm (63.58”)
Rear : 261 mm (10.28”)
T1-3-8
GENERAL / Component Specifications
• Front Attachment
CYLINDER
Lift Arm (Left/Right)
Rod Diameter ........................................... 95 mm (3.74”)
Cylinder Bore............................................ 145 mm (5.71”)
Stroke ....................................................... 930 mm (36.61”)
Fully Retracted Length ............................. 1481 mm (58.31”)
Plating Thickness ..................................... 30 µm (1.2 µin)
T1-3-9
Bucket
110 mm (4.33”)
185 mm (7.28”)
510 mm (20.08”)
1240 mm (48.82”)
30 µm (1.2 µin)
Steering
45 mm (1.77”)
70 mm (2.76”)
542 mm (21.34”)
900 mm (35.43”)
30 µm (1.2 µin)
GENERAL / Component Specifications
ELECTRIC COMPONENT
ENGINE OIL PRESSURE SENSOR
Operation Pressure .................................. 29.4 kPa (0.3 kgf/cm2)
COOLANT TEMPERATURE SENSOR
Operation Temperature ............................ 25 to 120 °C (77 to 248 °F)
AIR FILTER RESTRICTION SWITCH
Operation Pressure .................................. 6.3±0.6 kPa (635±58 mmH2O)
FUEL LEVEL SENSOR
Resistance Value...................................... Empty: 90+100Ω, Full: 100-4Ω
ENGINE OIL TEMPERATURE SENSOR
Operation Temperature ............................ -30 to 120 °C (-22 to 248 °F)
BATTERY RELAY
Voltage/Current ........................................ 24 V⋅100 A
INTAKE AIR HEATER RELAY
Voltage...................................................... 24 V
HORN
Voltage/Current ........................................ 24 V⋅3.0±0.5 A
Sound Pressure........................................ 113±5 dB (A) @ 2 m (6’ 7”)
T1-3-10
GENERAL / Component Specifications
ILLUMINATION
(Standard Version)
Work Light ................................................ : Halogen 24 V, 55/70 W
Cab Light .................................................. : 24 V, 10 W
Head Light ................................................ : Halogen 24 V、75/70 W
Turn Signal Light ...................................... : Front : 24 V, 25 W
:Rear : 24 V, 21 W
Clearance Light ........................................ : 24 V, 5 W
License Light ............................................ : 24 V, 12 W
Reverse Light ........................................... : 24 V, 21 W
Tail Light ................................................... : 24 V, 5 W
Brake Light ............................................... : 24 V, 21 W
(Europe Version)
Work Light ................................................ : Halogen 24 V, 70 W
Cab Light .................................................. : 24 V, 10 W
Head Light ................................................ : Halogen 24 V、75/70 W
Turn Signal Light ...................................... : 24 V, 21 W
Clearance Light ........................................ : 24 V, 4 W
License Light ............................................ : 24 V, 10 W × 2 pcs
Tail Light ................................................... : 24 V, 10 W
Brake Light ............................................... : 24 V, 21 W
AIR CONDITIONER
Refrigerant................................................ 134a
Cooling Ability........................................... 4.65 kW (16.74 MJ, 3999 kcal) or more
Cool Air Volume........................................ 550 m3/h or more
Heating Ability........................................... 5.81 kW (20.92 MJ, 4997 kcal) or more
Warm Air Volume...................................... 400 m3/h or more
Temperature Adjusting System ................ Electronic Type
Refrigerant Quantity ................................. 1000±50 g
Compressor Oil Quantity .......................... 160 cm3
EMERGENCY STEERING PUMP UNIT
Type.......................................................... Electric Motor Operated Type
Maximum Flow ......................................... 17 L/min (4.49 gpm) @10.3 MPa (105 kgf/cm2)
ELECTRIC MOTOR
Voltage...................................................... 24 V, 2.4 kW
T1-3-11
GENERAL / Component Specifications
(Blank)
T1-3-12
MEMO
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SECTION 2
SYSTEM
—CONTENTS—
Group 1 Control System
Group 4 Electrical System
Outline ...................................................... T2-1-1
Outline ...................................................... T2-4-1
Engine Control.......................................... T2-1-6
Main Circuit............................................... T2-4-2
Pump Control ......................................... T2-1-15
Electric Power Circuit................................ T2-4-3
Transmission Control.............................. T2-1-20
Indicator Light Check Circuit ..................... T2-4-4
Other Controls ........................................ T2-1-41
Accessory Circuit ...................................... T2-4-5
Control by Electric and Hydraulic
Preheat Circuit .......................................... T2-4-6
Combined Circuit .................................. T2-1-51
Starting Circuit .......................................... T2-4-8
Charging Circuit ...................................... T2-4-12
Group 2 ECM System
Serge Voltage Prevention Circuit ............ T2-4-14
Outline ...................................................... T2-2-1
Engine Stop Circuit ................................. T2-4-16
Fuel Injection Control ............................... T2-2-2
Lamplight Circait ..................................... T2-4-17
Head Light Circuit ................................... T2-4-18
Group 3 Hydraulic System
Outline ...................................................... T2-3-1
Turn Signal Circuit .................................. T2-4-22
Main Circuit .............................................. T2-3-2
Brake Light Circuit .................................. T2-4-23
Pilot Circuit ............................................. T2-3-13
Hazard Light Circuit ................................ T2-4-24
Steering Circuit ....................................... T2-3-26
Horn Circuit............................................. T2-4-25
Hydraulic Drive Fan Circuit ..................... T2-3-32
Reverse Light/Buzzer Circuit .................. T2-4-26
Parking Brake Circuit .............................. T2-4-28
Emergency Steering Check
Circuit (Optional) ................................... T2-4-30
4HAT-2-1
(Blank)
4HAT-2-2
SYSTEM / Control System
GENERAL
There are four controllers as shown below with MC –
Main Controller – installed at their center.
• MC: Main Controller
• ICF: Information Controller
• ECM: Engine Control Module
• Monitor Unit
Controllers are mutually connected through CAN, and
each controller uploads analog signals detected by
sensors and switches as well as analog output signals
of solenoid valves on the CAN by converting them into
digital ones.
As the signals are processed into the digital ones, a
large amount of signals detected at each controller can
be transmitted through few wires in a shirt time.
MC, ECM, and monitor unit display indications on
monitors and make various controls of the vehicle
body by using analog signals received by each
controller as well as digital signals detected on the
CAN.
ICF stores machine history, receives digital signals for
various adjustments from Dr-ZX, transmits them to the
CAN, and transmits the vehicle body signal (digital
signal) received by each controller to Dr-ZX.
A GPS-provision (optional) vehicle makes location
arithmetic operation, utilising signals received by
artificial sattelites, and transmits body information to
the e-service host computer through artificial satellites.
(Refer to the TROUBLESHOOTING/ICF)
Sensors, Switches and
Solenoid Valves
GPS
Monitor
Unit
S
Dr-ZX
Receipt and Transmission
by Analog Signal
ICF
Receipt and
Transmission by
Digital Signal
ECM1
CAN
MC
ECM2
S
CAN
(Exclusive between
ECM1 and ECM2)
S
T2-1-1
SYSTEM / Control System
MC, ECM, and Monitor Unit are used for various
operation controls of the body.
• Analog input signals from sensors and switches
attached to devices other than the engine and
monitor unit as well as analog output signals from
solenoid valves are transmitted into the MC, and
converted into digital signals to be uploaded on the
CAN.
• Analog input signals from sensors attached to the
engine are transmitted to the ECM, and converted
into digital signals to be uploaded on the CAN.
• Analog input signals from cabin, and analog input
signals from sensors and switches necessary for
indication of the monitor are transmitted into the
monitor unit, and converted into digital signals to be
uploaded on the CAN.
Each controller detects lacking information necessary
for the control program from among the CAN data.
(digital signals)
Each controller makes various control program
arithmetic operations using the detected data (digital
signals), outputs actuation signals to the solenoid
valves unit and torque control solenoid valve, and
controls the pump, engine, transmission, and valves.
Analog signals from various sensors, switches, and
solenoid valves are periodically transmitted into each
controller, and converted into digital signals to be
uploaded on the CAN.
By repeating the above operations, the vehicle body
movement is watched and controlled.
T2-1-2
SYSTEM / Control System
Injectors
Sensors and Switches
for Vehicle Body
MC
ECM2
ECM1
Transmission
Solenoid Valves
for Vehicle Body
Engine
Sensors and
Switches
Sensor Switches
for Cab and Monitor
Solenoid Valves
Monitor
Unit
Relays for
Cab
Sensors and
Switches
Switches for
Traveling
Light-emitting
Diodes
Dr-ZX
ICF
GPS
T4HA-02-01-001
T2-1-3
SYSTEM / Control System
Sensors and switches to detect signals for various
operation controls and their controllers are as shown
below.
Input Signals
• Accelerator Pedal Sensor
• Driving Mode Switch
• Work Mode Selector Switch
• Fan Reverse Switch
• Ride Control Switch
• Parking Brake Pressure Sensor
• Pump Delivery Pressure Switch
• Imprement Pressure Sensor
• Hydraulic Oil Temperature sensor
• Clutch Cut Position Sensor
• Lift Arm Kick-out Switch
• Lift Arm Angle Sensor (OP)
• Lift Arm Auto-leveler Upwards
Set Switch (OP)
• Lift Arm Auto-leveler Downwards
Set Switch (OP)
•
Output Signals
Engine Control
→
→
→Accelerator Pedal Control
→
→
→
→
→
→
→
→
→
→
MC
→Automatic Warming Up Control
→Engine Speed Reduction Control
Pump Control
→Standard Torque Control
→Torque Reduction Control
Other Controls
→Hydraulic Fan Cooling Control
→Hydraulic Fan Cleaning Control
→Transmission Alarm Control
→Forward/Reverse Indicator Control
→Reverse Traveling Alarm Control
→Parking Brake Alarm Control
→
→
CAN
(See next chart)
NOTE: OP : Stands for optional.
* : Controls for optional parts provision
machines only
T2-1-4
Control by Electric and Hydraulic
Combined Circuit
→*Ride Control
Bucket Auto-leveler Control
Lift Arm Float Control
→Lift Arm Kick-out Control
→*Lift Arm Auto-leveler Upward Control
→*Lift Arm Auto-leveler Downward Control
SYSTEM / Control System
Input Signal
(See previous chart)
• Forward/Reverse Lever
• Shift Switch
→
→
• Down Shift Switch
• Up Shift Switch
→
→
• Hold Switch
• Forward/Reverse Selector Switch
• Forward/Reverse Switch
→
→
→
Transmission control
→Neutral Control
→Forward/Reverse Lever Priority Control
→Forward/Reverse Selector Control While
Traveling
CAN
MC
• Brake Pressure Sensor
→
• Torque Converter Input Speed Sensor →
• Torque Converter Output Speed Sensor →
• Transmission Middle Shaft Sensor
→
• Vehicle Speed Sensor
→
(Refer to the SYSTEM/ECM System)
Output Signal
→Manual Speed Shift Control
→Automatic Speed Shift Control
→Down Shift Control
→Up Shift Control
→Clutch Cut Control
→Shift Holding Control
→
ECM1
• Engine Coolant Temperature Sensor
→
• Torque Converter Oil Temeperature
Sensor
→
Monitor
Unit
NOTE: ECM controls the engine speed and others
based on the target engine speed
transmitted from the MC and the converted
signal of the torque curve, and on the
signals detected by the sensors installed at
the engine. For details, refer to the
SYSTEM/ECM System.
T2-1-5
ECM2 →(Refer to the SYSTEM/ECM System)
SYSTEM / Control System
ENGINE CONTROL
Following engine controls are made.
• Accelerator pedal Control
• Automatic warming up control
• Engine speed reduction control
T2-1-6
SYSTEM / Control System
Engine Control System Layout
Work Mode
Selector Switch
L
Accelerator Pedal
Hydraulic Oil
Temperature
Sensor
Accelerator Pedal Sensor
N
P
Main Pump Delivery
Pressure Switch
Shift Switch
ECM2
MC
Transmission
ECM1
Engine
Torque Converter Output
Speed Sensor
Torque Converter Input
Speed Sensor
Monitor
Unit
Engine Coolant
Temperature Sensor
T2-1-7
T4HA-02-01-002
SYSTEM / Control System
Accelerator Pedal Control
Purpose: Control of the engine speed in response to
stepping amount of accelerator
Engine Actual
Speed
Operation:
1. MC converts the input value into the target engine
speed, and transmits it to the ECM1.
Maximum
Speed
2. ECM1 transmits the target engine speed
command value to the ECM2, and controls the
engine speed.
NOTE: Output value of the accelerator pedal
sensor is 0.5 V – 4.5 V.
NOTE: In case the accelerator pedal sensor
becomes abnormal, the MC makes
back-up control, and the engine speed is
fixed at about 1000 min-1.
NOTE: In case the MC becomes out of order, or
the CAN fails, the ECM makes back-up
control, and the engine speed is fixed at
about 1000 min-1.
NOTE: In case the MC becomes out of order with
the accelerator remaining normal, control
of the engine speed is possible by
connecting the accelerator pedal sensor
wires directly to the ECM.
T2-1-8
Minimum
Speed
Minimum
Speed
Maximum
Speed
Target
Engine
Speed
SYSTEM / Control System
Accelerator Pedal
Accelerator Pedal Sensor
ECM2
MC
Transmission
ECM1
Engine
Monitor
Unit
T4HA-02-01-003
T2-1-9
SYSTEM / Control System
Automatic Warming Up Control
Purpose: Automatic warming up of the engine in
response to the hydraulic oil temperature
Engine
Actual
Speed
Operation:
1. At start of the engine, if the hydraulic oil
temperature is 0°C (32°F) or below, the MC
transmits signal to the ECM1 for setting the
engine minimum speed at 1000 min-1.
Maximum
Speed
Automatic
Warming Up
Speed
2. ECM1 transmits the command value to the ECM2
to increase the minimum engine speed to 1000
min-1.
3. When the engine coolant temperature or
hydraulic oil temperature is 40°C (104°F) or
above, or when 10 minutes have passed, the MC
stops signals, and the ECM2 decreases the
engine minimum speed to the idling value.
NOTE: At start of the engine, if the hydraulic oil
temperature is 1°C (34°F) or above,
automatic warming up control is not made.
NOTE: In case the hydraulic oil temperature
sensor becomes abnormal, automatic
warming up control is not made.
NOTE: When the parking brake switch is turned
OFF, automatic warming up control is
released.
NOTE: In case automatic warming up control is
released by Dr. ZX, retrieve the automatic
warming up control effective by Dr. ZX the
moment releasing becomes unnecessary.
(Retrieving is impossible by just turning the
key switch OFF.)
T2-1-10
Speed
Increase
Minimum
Speed
Minimum
Speed
Maximum
Speed
Target Engine
Speed
SYSTEM / Control System
Hydraulic Oil
Temperature Sensor
ECM2
Transmission
MC
ECM1
Engine
Monitor
Unit
Engine
Coolant
Temperature
Sensor
T4HA-02-01-004
T2-1-11
SYSTEM / Control System
Engine Speed Reduction Control
Purpose: Reducing fuel consumption and improving
fuel consumption rate by lowering engine
speed in case traveling digging has been
made to the extent the engine almost stalls
Engine
Actual
Speed
Power Mode (P)
Maximum
Speed
Normal Mode (P)
Operation:
1. When signal of the selected work mode is
transmitted to the MC, it starts the engine speed
reduction program corresponding to the selected
work mode.
• When power mode (P) is selected, engine speed
reduction control is not made, which is
advantageous in making much of production.
• When normal mode (N) is selected, engine speed
is reduced to the speed within the set range,
which is advantageous in making much of
production as well as low fuel consumption.
• When light mode (L) is selected, engine is
reversed at the maximum speed within the range
larger than that for normal mode (N), which is
advantageous in making much of low fuel
consumption.
Light Mode (L)
Minimum
Speed
2. When traveling digging is started, MC detects
signals from the accelerator pedal sensor, pump
delivery pressure switch, and torque converter
output speed sensor, and transmits the target
engine speed to the ECM1 by figuring out the
most suitable engine speed reduction in response
to the traveling digging load applied to the body.
3. In traveling digging, the larger the load applied to
the body is, the larger the engine speed reduction
is.
4. ECM1 transmits the target engine speed
command value to the ECM2, and reduces the
engine speed to the target speed.
NOTE: In case signal from the work mode selector
switch is not transmitted to the MC,
back-up control of fixing the work mode to
normal is made.
NOTE: In case either of the accelerator pedal
sensor, main pump delivery pressure
switch, or torque converter input speed
sensor becomes abnormal, engine speed
reduction control is not made.
T2-1-12
Minimum
Speed
Maximum
Speed
Target
Engine Speed
Conceptual Diagram of
Maximum Speed Reduction Control
NOTE: Shift switch has two switches, and their
combination of ON varies depending on
each speed shift. Controller judges which
speed shift has been selected by the
combination of the two input signals.
NOTE: Each mode switch of the work mode
selector switch is supplied with respectively
different voltages from the monitor unit, and
when the switch selects a mode, the MC
judges which mode has been selected by
the input voltage.
SYSTEM / Control System
Work Mode
Selector Switch
Accelerator Pedal
L
Accelerator Pedal Sensor
N
P
Main Pump Delivery
Pressure Switch
Shift Switch
ECM2
MC
Transmission
ECM1
Engine
Torque Converter
Output Speed Sensor
Torque Converter
Input Speed Sensor
Monitor
Unit
T4HA-02-01-005
NOTE: Illustration shows flow of the signal in case
normal mode (N) of the work mode selector
switch and Speed 1 of the shift switch have
been selected.
If traveling digging is thus continued until
traveling is stopped, the engine maximum
speed is reduced to the maximum reduced
speed when normal mode is selected.
T2-1-13
SYSTEM / Control System
(Blank)
T2-1-14
SYSTEM / Control System
PUMP CONTROL
Following pump controls are made.
• Standard Torque Control
• Torque Reduction Control
Pump Control System Layout
Accelerator Pedal
Accelerator Pedal Sensor
Main Pump Delivery
Pressure Switch
ECM2
MC
Transmission
ECM1
Engine
Main Pump
regulator
Pump Torque Control
Solenoid Valve
Torque Converter
Output Speed Sensor
Monitor
Unit
Torque Converter
Input Speed Sensor
T4HA-02-01-006
T2-1-15
SYSTEM / Control System
Standard Torque Control
Purpose: Effectively utilizing engine horsepower by
changing pump flow in response to increase
or decrease of engine speed
Operation:
1. When accelerator pedal is stepped, MC makes
arithmetic operation of the target engine speed.
2. MC makes arithmetic operation of the pump
maximum tilting angle by receiving the target
engine speed signal, and transmits signal to the
pump torque control solenoid valve.
Q
Flow
P-Q Line
3. Pump torque control solenoid valve transmits pilot
pressure corresponding to the amplitude of signal
to the main pump regulator, and controls the
pump flow rate.
NOTE: In case the pump torque control solenoid
valve becomes abnormal, standard-torque
control is not made.
Pressure
T2-1-16
P
SYSTEM / Control System
Accelerator Pedal
Accelerator Pedal Sensor
ECM2
MC
Transmission
ECM1
Engine
Main Pump
Regulator
Pump Torque Control
Solenoid Valve
Monitor
Unit
T4HA-02-01-007
T2-1-17
SYSTEM / Control System
Torque Reduction Control
Purpose: Effectively utilizing engine horsepower by
changing pump flow in response to increase
or decrease of the engine speed due to
traveling load
Operation:
1. When accelerator pedal is stepped, MC makes
arithmetic operation of the target engine speed.
Q
Flow
2. MC makes arithmetic operation, using the target
engine speed and signals from the main pump
delivery pressure switch, torque converter input
speed sensor, and torque converter output speed
sensor, and figures out the pump maximum tilting
angle most suitable to each time to transmit it to
the pump torque control solenoid valve.
P-Q Line
3. Pump torque control solenoid valve transmits pilot
pressure corresponding to the amplitude of signal
to the main pump regulator, and controls the
pump flow rate.
4. If load applied to the engine becomes large and
decreases the actual engine speed than the
target speed, the pump tilting angle is decreased
to reduce delivery flow. Thus, maneuverability of
the vehicle body is improved.
5. MC makes arithmetic operation of the actual
engine speed, receiving signal from the torque
converter input speed sensor.
Pressure
P
NOTE: In case the accelerator pedal becomes
abnormal, the back-up control of the
accelerator controls and fixes the engine
speed at 1000 min-1.
NOTE: In case signal from either the main pump
delivery pressure switch, torque converter
input speed sensor, or torque converter
output speed sensor is not transmitted to
the MC, it does not make torque reduction
control, but makes pump control by the
standard-torque control.
NOTE: In case the pump torque control solenoid
valve
becomes
abnormal,
neither
standard-torque
control
nor
torque
reduction control is made.
T2-1-18
SYSTEM / Control System
Accelerator Pedal
Accelerator Pedal Switch
Main Pump Delivery
Pressure Switch
ECM2
MC
Transmission
ECM1
Engine
Main Pump
Regulator
Pump Torque Control
Solenoid Valve
Torque Converter
Output Speed Sensor
Monitor
Unit
Torque Converter
Input Speed Sensor
T4HA-02-01-008
T2-1-19
SYSTEM / Control System
TRANSMISSION CONTROL
Following transmission controls are made.
• Neutral Control
• Forward/Reverse Lever Priority Control
• Forward/Reverse Selector Control While
Traveling
• Manual Speed Shift Control
• Automatic Speed Shift Control
• Down Shift Control
• Up Shift Contrl
• Clutch Cut Control
• Shift Holding Control
T2-1-20
SYSTEM / Control System
Transmission Control System Layout
Key Switch
Driving Mode Switch
Brake Pressure
Sensor
Accelerator
Pedal Sensor
M
Brake Pedal
Accelerator Pedal
L
N
H
Reverse Clutch
Solenoid Valve
Clutch Cut Position
Switch
Forward
Clutch Solenoid
Valve
Transmission
Middle Shaft
Sensor
OFF
S
Transmission
N
D
MC
ECM2
ECM1
Engine
Shift Switch
1 2 3 4
Parking Brake
Speed Shift
Solenoid Valve
Parking Brake
Pressure Sensor
Monitor
Unit
Parking Brake
Solenoid Valve
Vehicle Speed
Sensor
Torque
Converter
Input
Speed
Sensor
Forward/Reverse
Lever
F
Torque
Converter
Output
Speed
Sensor
N
R
Forward/Reverse
Switch
F
N
OFF
DOWN
R
ON
UP
HOLD
OFF
Forward/Reverse
Selector Switch
Up-shift/Down-shift
Switch
Hold Switch
Parking Brake
Switch
T2-1-21
ON
T4HA-02-01-009
SYSTEM / Control System
Neutral Control
Purpose: Protection of transmission during working of
parking brake by restricting clutch connection despite operation of forward/reverse
lever or forward/reverse switch
Operation:
1. In case either of the signal from forward/reverse
lever, forward signal or reverse signal of the forward/reverse switch is transmitted to the MC, the
MC confirms the detected value of the parking
brake pressure sensor.
IMPORTANT: Be careful that in case the parking
brake pressure sensor is abnormal,
traveling is possible even if the
parking brake switch is ON and the
parking brake is at workbecause the
parking brake alarm lamp is turned
OFF and fixed (release).
2. When the parking brake pressure is higher than
the set pressure, the MC transmits signal to the
clutch solenoid valve, but does not when lower
than that.
NOTE: When the pilot pressure is transmitted, the
parking brake of the vehicle body is released.
NOTE: In case short-circuiting takes place inside
the forward/reverse lever, transmission is
made neutral forcedly.
NOTE: In case electric abnormality takes place
involving the forward/reverse switch, traveling by the forward/reverse lever is possible as an emergency measure.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
T2-1-22
SYSTEM / Control System
Forward Clutch
Solenoid Valve
MC
Reverse Clutch
Solenoid Valve
ECM2
ECM1
Engine
Transmission
Parking Brake
Pressure Sensor
Monitor
Unit
Parking Brake
Solenoid Valve
Parking Brake
Forward/Reverse
Lever
F
N
R
Forward/Reverse
Switch
F
N
OFF
ON
R
ON
OFF
Forward/Reverse
Selector Switch
Parking Brake
Switch
NOTE: Illustration shows flow of the signal in case.
Forward of the forward/reverse lever have
been selected with the parking brake switch
turned OFF – transmitting brake release
signal.
T2-1-23
T4HA-02-01-010
SYSTEM / Control System
Forward/Reverse Lever Priority Control
Purpose: Smoothening danger-preventive function in
forward/reverse operation by giving priority to
signal from forward/reverse lever over signal
from forward/reverse switch
Operation:
1. In case the forward/reverse lever is operated
while traveling using the forward/reverse switch,
the MC disables operation of the forward/reverse
switch, and makes forward/reverse control by input signal from the forward/reverse lever.
2. For restarting operation using the forward/reverse
switch, have the forward/reverse switch effective
again by turning the forward/reverse selector
switch ON while making both the forward/reverse
lever and the forward/reverse switch at the neutral
position.
3. From then on until the forward/reverse lever is
operated next, the MC makes forward/reverse
control by the forward/reverse switch input signal.
NOTE: In case short-circuiting takes place inside
the forward/reverse lever, transmission is
made neutral forcedly, and traveling becomes impossible, which requires towing.
However, in case the forward/reverse
switch is out of order, traveling by the forward/reverse lever is possible as an
emergency measure.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
T2-1-24
SYSTEM / Control System
Forward Clutch
Solenoid Valve
MC
ECM1
Reverse Clutch
Solenoid Valve
ECM2
Engine
Transmission
Monitor
Unit
Forward/Reverse
Lever
F
N
R
Forward/Reverse
Switch
F
N
OFF
R
ON
Forward/Reverse
Selector Switch
T4HA-02-01-011
NOTE: Illustration shows flow of the signal in case
forward of the forward/reverse selector
lever has been selected while traveling reverse of the forward/reverse lever.
T2-1-25
SYSTEM / Control System
Forward/Reverse Selector Control While Traveling
Purpose: Protection of transmission in traveling at set
speed and above by preventing forward/reverse selector unless the vehicle
speed is lowered than that
Operation:
1. In case the forward/reverse lever is changed to
reverse while traveling forward at speed higher
than the speed allowed for operation of the forward/reverse lever, the MC lowers the speed shift
by transmitting speed shift signal of Speed
4→3→2 to the transmission if the speed shift is
Speed 4.
2. If the vehicle speed is lowered to the set speed by
operation of the brake pedal or otherwise, the MC
transmits signal to the reverse clutch solenoid
valve to have the clutch shifted reverse.
3. As the speed increases when the accelerator
pedal is stepped, the MC transmits speed shift
signal of Speed 2 to Speed 3 to each speed shift
solenoid valve, and increases the speed shift.
NOTE: In case the forward/reverse lever is operated when the vehicle speed is below the
value allowed for changeover of the forward/reverse clutch, the forward/reverse
clutch is operated regardless of the speed
shift.
NOTE: Shift switch has two switches, and the
combination of their ON varies depending
on each speed shift. Controller judges
which speed shift has been selected by the
combination of the two input signals.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
T2-1-26
SYSTEM / Control System
Accelerator Pedal
Sensor
Brake
Sensor
Accelerator Pedal
Brake Pedal
Shift Switch
Forward Clutch
Solenoid Valve
MC
ECM1
ECM2
Engine
1 2 3 4
Speed Shift Solenoid Valve
Transmission
Monitor
Unit
Reverse Clutch
Solenoid Valve
Vehicle Speed
Sensor
Forward/Reverse
Lever
F
N
R
Forward/Reverse
Switch
F
N
OFF
R
ON
Forward/Reverse
Selector Switch
T4HA-02-01-012
NOTE: Illustration shows flow of the signal in case
reverse of the forward/reverse lever has
been selected and the brake pedal has
been stepped while traveling forward at
Speed 4 above the value allowable for selection of the forward/reverse clutch.
T2-1-27
SYSTEM / Control System
Manual Speed Shift Control
Purpose: Making speed shift manually
NOTE: MC is so programmed as to dtermine necessary vehicle speed ranges for changing
to the respective speed shifts.
Operation:
1. When manual (M) of the Driving Mode switch is
selected, the MC is provided with voltage of 1V.
2. Manual speed shift program is started in the MC.
3. Shift switch is the rorary type, and has two
switches inside. When the speed shift is selected
from among Speed 1 through Speed 4, signal of
the selected speed shift is transmitted to the MC
depending on the combination of ON inside the
speed shift switch.
Speed Shift
Speed
1
Internal Switch
1
ON
Internal Switch
2
Speed
2
Speed
3
Speed
4
ON
ON
NOTE: In case speed shift from Speed 3 to Speed
1 is attempted while traveling by operating
the speed shift switch, Speed 2 is automatically selected first, and Speed 1 is
reached after the vehicle speed is lowered
to the speed range for Speed 1.
NOTE: In case the solenoid valve of either of the
Speed 1, Speed 3, or Speed 4 becomes
abnormal, the travel speed will be fixed to
Speed 2. In case either of the forward
clutch solenoid valve, reverse clutch solenoid valve, or Speed 2 solenoid valve becomes abnormal, only the abnormal one
cannot be used.
ON
4. MC transmits signal to the solenoid valve of the
selected speed shift.
5. If forward or reverse of the forward/reverse lever
or the forward/reverse switch is selected, traveling
is started when the accelerator pedal is stepped.
6. When the vehicle speed reaches the set speed
change to the selected speed shift, the MC
transmits signal to the solenoid valve of the selected speed shift.
NOTE: In case speed shift is raised, the selected
speed shift is immediately obtained regardless of the vehicle speed.
NOTE: Shift switch has two switches, and the
combination of their ON varies depending
on each speed shift. Controller judges
which speed shift has been selected by the
combination of the two input signals.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
NOTE: Each mode switch of the Driving Mode
switch is supplied with respectively different
voltages from the monitor unit, and if a
switch is selected, the MC judges which
mode has been selected.
NOTE: Speed shift selected by the speed shift
switch is the highest speed shift.
T2-1-28
SYSTEM / Control System
Driving Mode
Switch
Accelerator Pedal
Sensor
M
Brake Pressure
Sensor
Brake Pedal
Accelerator
Pedal
L
N
H
Shift Switch
Forward Clutch
Solenoid Valve
MC
ECM1
ECM2
1 2 3 4
Engine
Monitor
Unit
Speed Shift Solenoid Valve
Transmission
Vehicle Speed
Sensor
Forward/Reverse
Lever
F
N
R
Forward /Reverse
Switch
F
N
OFF
R
ON
Forward/Reverse
Selector Switch
T4HA-02-01-013
NOTE: Illustration shows flow of the signal in case
forward of the forward/reverse lever has
been selected when manual of the Driving
Mode switch and Speed 1 of the speed shift
switch have been selected.
T2-1-29
SYSTEM / Control System
Automatic Speed Shift Control
Purpose: Automatically changing speed shift with
three kinds of timing selection of automatic
speed shift change
Operation:
4. MC transmits signal to the right speed shift solenoid valve in response to the output value each
time of the torque converter input speed sensor,
torque converter output speed sensor, vehicle
speed sensor, and accelerater pedal sensor. MC
eventually makes speed shift control until the selected speed shift.
1. If either of L, N, and H of the Driving Mode switch
is selected, the MC is supplied with votage corresponding to the selected mode.
Mode
Automatic L
Automatic
N
Automatic
H
Output
Voltage
2V
3V
4V
2. MC started the selected automatic speed shift
program.
• In Automatic L control, the timing of speed shifting up
is slow when started at Speed 2, which is advantageous in making much of low fuel consumption.
• In Automatic N control, the timing of speed shifting
up is fast when started at Speed 2, which is advantageous in making much of production as well as low
fuel consumption.
• In Automatic H control, though started at Speed 2,
besides slow speed shifting up, speed shift to Speed
1 is necessary if traveling load is high, which is advantageous in making much of production.
NOTE: In whichever of Modes L, N, and H, starting
is made at Speed 1, if the speed shift switch
of Speed 1 is selected.
3. Shift switch is the rorary type, and has two
switches inside. When the speed shift is selected
from among Speed 1 through Speed 4, signal of
the selected speed shift is transmitted to the MC
depending on the combination of ON inside the
speed shift switch.
Speed Shift
Speed
1
Internal Switch
1
ON
Internal Switch
2
Speed
2
Speed
3
Speed
4
ON
ON
ON
T2-1-30
NOTE: MC is so programmed as to dtermine necessary vehicle speed ranges for changing
to the respective speed shifts and accelerator pedal output value. Therefore, in
case Automatic L of the Driving Mode
switch and Speed 3 of the speed shift
switch are selected at start of traveling,
traveling is started at Speed 2 first, and
shifted up to Speed 3 as the vehicle speed
increases. Conversely, in case speed shift
from Speed 3 to Speed 1 is attempted while
traveling by operating the speed shift switch,
Speed 2 is automatically selected first, and
Speed 1 is reached after the vehicle speed
is lowered to the speed range for Speed 1.
NOTE: In case the Driving Mode switch becomes
out of order, the MC makes speed shift
control in the manual traveling mode.
NOTE: In case the solenoid valve of either of the
Speed 1, Speed 3, or Speed 4 becomes
abnormal, the travel speed will be fixed to
Speed 2. In case either of the forward
clutch solenoid valve, reverse clutch solenoid valve, or Speed 2 solenoid valve becomes abnormal, only the abnormal one
cannot be used.
NOTE: In case the travel speed sensor has become abnormal, the travel speed is calculated using the transmission intermediate
shaft sensor, but with a large error. In case
both of the travel speed sensor and the
transmission intermediate shaft sensor
have become abnormal, travel at Speed 2
is fixed.
NOTE: Speed shift selected by the speed shift
switch is the highest speed shift.
SYSTEM / Control System
Driving Mode
Switch
Accelerator Pedal
Sensor
M
Brake Pressure
Sensor
Brake Pedal
Accelerator Pedal
L
N
H
Shift Switch
Forward Clutch
Solenoid Valve
Transmission
MC
ECM1
ECM2
Engine
1 2 3 4
Speed Shift Solenoid Valve
Vehicle Speed
Sensor
Monitor
Unit
Forward/Reverse
Lever
Torque Converter
Input Speed Sensor
Torque Converter
Output Speed Sensor
F
N
R
Forward/Reverse
Switch
F
N
OFF
R
ON
Forward/Reverse
Selector Switch
T4HA-02-01-014
NOTE: Illustration shows flow of the signal in case
Automatic L mode of the Driving Mode
switch, Speed 4 of the speed shift switch,
and forward of the forward/reverse selector
lever have been selected, while the brake
pedal has been stepped.
T2-1-31
SYSTEM / Control System
Down Shift Control
Purpose: Decreasing the speed shift by pushing the
switch installed at the right console.
Operation:
1. When traveling at Speed 4 in Automatic L mode of
the Driving Mode switch, signal is transmitted to
the MC by pushing the down shift switch once.
2. When traveling faster than the allowable speed
shift, the MC cancels the signal from the down
shift switch, but transmits signal to the speed shift
solenoid valve of Speed 3, when traveling slow.
8. In case of the following, the down shift switch
control is canceled.
• Operation of the forward/reverse lever or the forward/reverse switch
• Operation of the shift switch
• Operation of the Driving Mode switch
• Pushing the hold switch
(Only in Automatic mode of the Driving Mode
switch)
3. Further, if the down shift switch is pushed and the
vehicle speed is lowered to the range allowing the
speed shift, the speed shift of Speed 2 is selected.
4. In case automatic mode of the Driving Mode
switch is selected, automatic speed shift control is
recovered three seconds after the speed shift has
lowered, and then the speed shift is automatically
raised once the vehicle speed increases.
5. By keeping pushing the down shift switch, the
speed shift is lowered to Speed 2, and Speed 2 is
kept during pushing.
6. If the down switch is pushed again within three
seconds after removing the finger once, Speed 1
is obtained in case the vehicle speed is slow
enough to allow the speed shift down.
7. When the down shift switch is pushed in manual
mode of the Driving Mode switch, in case the vehicle speed is slow enough to allow the down shift,
the speed shift is lowered and the shifted speed is
kept.
NOTE: In case the vehicle speed sensor becomes
abnormal, the MC receives signal from the
transmission middle shaft sensor, and controls by making arithmetic operation of the
vehicle speed allowable for the speed shift.
In case both the vehicle speed sensor and
the transmission middle shaft sensor are
abnormal, lowering the speed shift is possible as an emergency measure only when
the engine stops for one reason or another
but traveling is not stopped.
NOTE: Shift switch has two switches, and their
combination of ON varies depending on
each speed shift. Controller judges which
speed shift has been selected by the combination of the two input signals.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
NOTE: Each mode switch of the Driving Mode
switch is supplied with respectively different
voltages from the monitor unit, and when
the switch selects a mode, the MC judges
which mode has been selected by the input
voltage.
T2-1-32
SYSTEM / Control System
Driving Mode
Switch
Accelerator Pedal Sensor
Brake Pressure Sensor
M
Brake Pedal
Accelerator Pedal
L
N
H
Shift Switch
Transmission
Middle Shaft Sensor
Forward Clutch
Solenoid Valve
Reverse Clutch
Solenoid Valve
MC
ECM1
ECM2
Engine
1 2 3 4
Speed Shift Solenoid Valve
Transmission
Monitor
Unit
Vehicle
Speed Sensor
Forward/Reverse
Lever
F
N
R
Forward/Reverse
Switch
F
N
OFF
DOWN
R
ON
UP
HOLD
Forward/Reverse
Selector Switch
Up-shift/Down-shift
Switch
Hold Switch
NOTE: Illustration shows flow of the signal from the
MC in case Speed 3 has been selected
during forward traveling at Speed 4 and
Automatic L of the Driving Mode switch.
T2-1-33
T4HA-02-01-015
SYSTEM / Control System
Up Shift Control
Purpose: Raising the speed shift by putting the left
hand on the steering wheel and pressing the
switch installed at the right console
Operation:
1. Signal is transmitted to the MC by pushing the up
shift switch once when traveling at Automatic L
mode of the Driving Mode switch and Speed 4 of
the shift switch.
2. MC transmits signal to the speed shift solenoid
valve of Speed 2, and the speed shift is raised.
3. If the up shift switch is pushed, the speed shift is
further raised to Speed 3 and Speed 4.
4. In case automatic of the Driving Mode switch is
selected, the speed shift is raised, and returned to
the automatic speed shift control in three seconds,
eventually raising automatically to the speed shift
selected in advance.
5. In case manual of the Driving Mode switch is selected, the raised speed shift is kept.
6. In case the following operations are made, the up
shift switch is released.
• Operation of the forward/reverse lever or forward/reverse switch
• Operation of the shift switch
• Operation of the Driving Mode switch
• Pushing the hold switch
(only when the automatic of the Driving Mode
switch is selected)
NOTE: Even if the up shift switch is pushed during
traveling at the speed shift slected by the
shift switch, the speed shift is not raised
further.
T2-1-34
NOTE: Shift switch has two switches, and their
combination of ON varies depending on
each speed shift. Controller judges which
speed shift has been selected by the combination of the two input signals.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
NOTE: Each mode switch of the Driving Mode
switch is supplied with respectively different
voltages from the monitor unit, and when
the switch selects a mode, the MC judges
which mode has been selected by the input
voltage.
SYSTEM / Control System
Driving Mode
Switch
Accelerator Pedal
Sensor
M
Brake Pressure
Sensor
Brake Pedal
Accelerator Pedal
L
N
H
Shift Switch
Forward Clutch
Solenoid Valve
Reverse Clutch
Solenoid Valve
MC
ECM1
ECM2
Engine
1 2 3 4
Speed Shift Solenoid Valve
Transmission
Monitor
Unit
Forward/Reverse
Lever
F
N
R
Forward/Reverse
Switch
F
N
OFF
DOWN
R
ON
UP
HOLD
Forward/Reverse
Selector Switch
Up shift/Down shift/
Switch
Hold
Switch
NOTE: Illustration shows flow of the signal from the
MC in case Speed 2 has been selected
during forward traveling at Speed 1 and
Automatic L of the Driving Mode switch.
T2-1-35
T4HA-02-01-016
SYSTEM / Control System
Clutch Cut Control
Purpose: Enabling release of the forward/reverse
clutch of the transmission for making the
most of the engine torque by operating the
brake during operation of the front attachment.
Amount of stepping the brake at the time of
declutching can be selected from among
three kinds depending on the driver’s preference.
5. In case the brake pressure is lowered below the
set pressure by reducing the amount of stepping
of the brake pedal, signal transmitted to the clutch
solenoid valve is raised, and clutching is made
again.
Operation:
1. When either mode of the clutch cut position switch
is selected, voltage corresponding to the selected
mode is transmitted to the MC.
Mode
OFF
S
N
D
Input
Voltage
1V
2V
3V
4V
2. MC starts the corresponding clutch cut control
program.
• Clutch cut does not work in OFF mode.
• In Mode S, clutch cut is made at output voltage
equivalent to the set pressure of Mode S, and
clutching is made again at voltage equivalent to
pressures lower than that of Mode S.
• In Mode N, clutch cut is made at output voltage
equivalent to the set pressure of Mode N, and
clutching is made again at voltage equivalent to
pressures lower than that of Mode N.
• In Mode D, clutch cut is made at output voltage
equivalent to the set pressure of Mode D, and
clutching is made again at voltage equivalent to
pressures lower than that of Mode D.
3. In case the brake pedal is stepped in Mode S,
signal from the brake pressure sensor is transmitted to the MC.
4. For signal higher than the set voltage, the MC declutches by lowering signal transmitted to the excited solenoid valve among the respective solenoid valves.
T2-1-36
NOTE: In case either of the clutch cut position
switch and brake pressure sensor becomes
out of order, clutch cut control is not made
NOTE: Each mode switch of the clutch cut position
switch is supplied with respectively different
voltages from the monitor unit, and when
the switch selects a mode, the MC judges
which mode has been selected by the input
voltage.
SYSTEM / Control System
Brake Pressure
Sensor
Brake Pedal
Clutch Cut
Position Switch
OFF
Forward Clutch
Solenoid Valve
S
Reverse Clutch
Solenoid Valve
N
D
MC
ECM1
ECM2
Engine Transmission
Monitor
Unit
T4HA-02-01-017
NOTE: Illustration shows flow of the signal in case
the brake pedal has been stepped in Mode
S of the clutch cut position switch.
T2-1-37
SYSTEM / Control System
Shift Holding Control
Purpose: Enabling to hold the speed shift during towing or traveling uphill
Operation:
1. When the hold switch is pressed once, signal is
transmitted to the MC.
2. MC keeps transmitting signal to the speed shift
solenoid valve of each time, and after that the
speed shift is fixed even if the the accelerator or
the brake pedal is stepped.
NOTE: Speed shift holding control is made only
when automatic (L, N, or H) of the Driving
Mode switch is selected.
3. MC releases the speed shift holding control in
case the following operations are made or the
following switches are operated.
• Turning OFF the key switch
• Pushing the hold switch again
• Down shift switch
• Up shift switch
• Forward/reverse lever
• Forward/reverse selector switch (only when effective)
• Forward/reverse switch (only when effective)
• Speed shift switch
• Driving Mode switch
• Parking brake switch
T2-1-38
NOTE: Shift switch has two switches, and their
combination of ON varies depending on
each speed shift. Controller judges which
speed shift has been selected by the combination of the two input signals.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the controller judges the switch as neutral (N).
NOTE: Each mode switch of the Driving Mode
switch is supplied with respectively different
voltages from the monitor unit, and if a
switch is selected, the MC judges which
mode has been selected.
SYSTEM / Control System
Key Switch
Driving Mode Switch
Accelerator Pedal
Sensor
M
Brake Pressure
Sensor
Accelerator Pedal
Brake Pedal
L
N
H
Shift Switch
Forward Clutch
Solenoid Valve
MC
ECM2
ECM1
Engine
1 2 3 4
Speed Shift Solenoid Valve
Transmission
Monitor
Unit
Forward/Reverse
L
F
N
R
Forward/Reverse
Switch
F
N
OFF
DOWN
R
ON
UP
HOLD
Forward/Reverse
Selector Switch
Up-Shift/Down-Shift
Switch
Hold
Switch
T2-1-39
ON
OFF
Parking Brake T4HA-02-01-018
Switch
SYSTEM / Control System
(Blank)
T2-1-40
SYSTEM / Control System
OTHER CONTROLS
Following other controls are made.
• Hydraulic fan cooling control
• Hydraulic fan cleaning control
• Transmission alarm control
• Forward/reverse indicator control
• Reverse Traveling alarm control
• Parking brake alarm control
T2-1-41
SYSTEM / Control System
Hydraulic Fan Cooling Control
Purpose: Improving fuel consumption rate and noise
reduction by restricting the hydraulic fan
speed in response to oil temperature and
coolant temperature.
Operation:
1. When the engine is started, the fan pump rotates,
and discharges oil to the fan motor.
2. Signals from the hydraulic oil temperature sensor,
engine coolant temperature sensor, and torque
converter oil temperature sensor are simultaneously transmitted to the MC, and arithmetic
operation of three target hydraulic fan speeds are
carried out.
3. MC selects the highest speed, and transmits
signal to the flow control solenoid valve.
4. Flow control solenoid valve operates, and
pressure oil coming from it flows into the right end
of the flow control valve, so the flow control valve
spool moves left.
5. When the flow control valve spool moves left, part
of the pressure oil flowing to the fan motor flows to
the tank port, and the fan motor speed is lowered
accordingly.
6. In case oil temperature or coolant temperature of
any part is above the set temperature, the
hydraulic fan speed is maximum when the engine
speed is maximum.
7. In case oil temperature or coolant temperature of
any part is below the set temperature, the
hydraulic fan speed is lowered in response to the
datum of the highest temperature.
8. Besides, the signal from the outside air
temperature sensor also enters the MC, and
rotates the fan always at the maximum speed,
disregarding the controls in 2 through 7 in case
the air conditioner switch is ON at the outside air
temperature of 35 °C (95 °F) and above.
NOTE: In case any of the engine speed sensor,
hydraulic oil temperature sensor, engine
coolant
temperature
sensor,
torque
converter oil temperature sensor and out
side temperature sensor becomes out of
order, cooling by hydraulic fan control is
always made at the maximum speed.
T2-1-42
SYSTEM / Control System
At oil temperature or coolant temperature above the set temperature (Uncontrolled speed operation)
Fan Motor
Flow Control Valve
Hydraulic Oil Tank
Flow Control
Solenoid Valve
Hydraulic Oil Temperature Sensor
Fan Pump
Engine Coolant
Temperature Sensor
Out Side
Temperature
Sensor
MC
Air
Conditioner
Control
Panel
ECM1
ECM2
Transmission
Engine
Torque Converter
Oil Temperature Sensor
Monitor
Unit
T4HA-02-01-019
At oil temperature or coolant temperature below the set temperature (Controlled speed operation)
Fan Motor
Flow Control Valve
Hydraulic Oil Tank
Hydraulic Oil Temperature Sensor
Flow Control
Solenoid Valve
Fan Pump
Engine Coolant
Temperature Sensor
Out Side
Temperature
Sensor
MC
ECM1
ECM2
Transmission
Engine
Air
Conditioner
Control
Panel
Torque Converter
Oil Temperature Sensor
Monitor
Unit
T4HA-02-01-020
T2-1-43
SYSTEM / Control System
Hydraulic Fan Cleaning Control
Purpose: Controlling cleaning by hydraulic fan by
reversing the hydraulic fan to blow away
dust in case cleaning of the radiator, and oil
cooler are needed
Operation:
1. When the engine is started after preparing the
following conditions and turning the fan reverse
switch ON, signal is transmitted from the MC to
the reverse control solenoid valve.
2. When the reverse control solenoid valve is
operated, the reverse spool strokes, and the fan
motor rotation is reversed.
3. In reverse rotation, as hydraulic fan cooling
control is not made, the fan speed fluctuates from
maximum to minimum in response to the amount
of stepping of the accelerator pedal.
4. In case any one of the conditions below is
changed during reverse rotation, the engine
speed is immediately fixed to idling.
5. Hydraulic fan cleaning control is not released by
turning the fan reverse switch OFF only. Control is
released by the procedure of turning the fan
reverse switch OFF – turning the key switch OFF
– turning the key switch ON.
6. In case the engine speed is fixed to idling also, the
control is released by the procedure of turning the
fan reverse switch OFF – turning the key switch
OFF – turning the key switch ON.
Conditions:
• Fan switch: ON
• Parking brake switch: ON (Brake is effective.)
• Forward/reverse lever: neutral
• Forward/reverse switch: neutral
T2-1-44
NOTE: Reverse control solenoid valve is turned
ON temporarily when the key switch is
turned ON because the spool can stick in
case the reverse control solenoid valve is
not operated for a long time. It is also
turned ON once every one minute after the
key switch is turned ON. This operation is
not made during the hydraulic fan cleaning
operation.
SYSTEM / Control System
In cooling operation (Normal rotation)
Fan Motor
Reverse Spool
Reverse Control
Solenoid Valve
ECM2
Transmission
Engine
Hydraulic Oil
Tank
T4HA-02-01-027
In cleaning operation (Reverse rotation)
Fan Motor
Reverse Spool
Reverse Control Solenoid Valve
Hydraulic Oil
Tank
ECM2
Transmission
Engine
MC
ECM1
OFF
Parking Brake
Solenoid Valve
Parking Brake
Pressure Sensor
ON
Monitor
Unit
Fan Reverse
Switch
F
F
N
N
ON
R
R
OFF
Forward/Reverse
Lever
Forward/Reverse
Switch
Parking Brake
Switch
T2-1-45
T4HA-02-01-021
SYSTEM / Control System
Transmission Alarm Control
Purpose: Lighting the transmission alarm lamp on the
monitor unit for protection of the transmission in case of disorder of partslikely to
cause damage to the transmission
Operation: In case any of the parts shown right becomes out of order, the MC transmits signal
to the monitor unit, and the transmission
alarm lamp is lit.
Monitor
MC
• Torque converter input speed sensor
• Torque converter output speed sensor
• Vehicle speed sensor
• Transmission middle shaft sensor
• Forward/reverse lever
• Forward/reverse switch during work
ECM2
ECM1
Transmission
Engine
Torque Converter
Input Speed
Sensor
Torque Converter
Output Speed
Sensor
Monitor
Unit
Transmission
Alarm Lamp
Transmission
Middle Shaft Sensor
F
F
N
N
R
R
Forward/Reverse
Lever
Forward/Reverse Switch
T2-1-46
Vehicle Speed
Sensor
T4HA-02-01-022
SYSTEM / Control System
Forward/Reverse Indicator Control
Purpose: Lighting the forward/reverse indicator on the
monitor when the forward/reverse switch is
effective
NOTE: In case the forward/reverse lever is operated while traveling using the forward/reverse switch, input to the forward/reverse switch becomes ineffective,
and the vehicle body moves by operating
the forward/reverse lever. (Refer to the Forward/Reverse Lever Priority Control)
Operation:
1. Forward/reverse selector switch is turned ON after
the forward/reverse lever and the forward/reverse
switch are positioned at neutral.
2. Then the forward/reverse switch becomes
effective, and the monitor unit lights the
forward/reverse indicator of the monitor.
NOTE: Forward/reverse switch does not transmit
neutral signal. In case of no electric current
from the forward/reverse switch, the
controller judges the switch as neutral (N).
NOTE: In case the forward/reverse lever becomes
out of order, input to the forward/reverse
switch becomes ineffective, and the
forward/reverse indicator is unlit and fixed.
Monitor
MC
ECM1
Forward/Reverse Indicator
Monitor
Unit
F
F
N
N
OFF
R
R
ON
Forward/Reverse
Lever
Forward/Reverse
Switch
T2-1-47
Forward/Reverse
Selector Switch
T4GC-02-01-023
SYSTEM / Control System
Reverse Traveling Alarm Control
(Refer to the SYSTEM/Electric System)
Purpose: Sounding alarm buzzer when the forward/reverse lever or the forward/reverse
switch is selected
Operation:
1. When reverse of the forward/reverse lever or the
forward/reverse switch is selected, the MC earths
the terminal from the reverse light relay.
2. Reverse light relay is excited, and electric current
flows to the reverse light and the reverse buzzer.
Right
Reverse Light
Reverse Buzzer
MC
ECM1
F
N
Monitor
Unit
Reverse Light
Relay
R
Forward/Reverse
Lever
or
Forward/Reverse
Switch
From Terminal #108
of Fuse Box A
T2-1-48
Left
Reverse Light
T4GC-02-01-024
SYSTEM / Control System
Parking Brake Alarm Control
Purpose: Lighting the parking brake alarm lamp on the
monitor unit during parking operation of the
brake
NOTE: Parking brake of the vehicle body is
released if the pilot pressure flows in.
Operation:
NOTE: For operation circuit of the parking brake,
refer to the SYSTEM/Electric System.
1. When the parking brake switch is turned ON, the
MC confirms signal of the parking brake pressure
sensor.
2. At pressure below the set pressure, the MC
transmits signal to the monitor unit, and the
parking brake alarm lamp is lit.
IMPORTANT: Be careful that in case the parking
brake pressure sensor is abnormal,
traveling is possible even if the
parking brake switch is ON and the
parking brake is at work because the
parking brake alarm lamp is fixed to
OFF (release).
Monitor
MC
ECM2
ECM1
Transmission
Engine
Parking Brake
Alarm Lamp
Parking Brake
Pressure Sensor
Monitor
Unit
Parking Brake
ON
Parking Brake
Solenoid Valve
OFF
Parking Brake Switch
T4HA-02-01-025
T2-1-49
SYSTEM / Control System
(Blank)
T2-1-50
SYSTEM / Control System
CONTROL BY ELECTRIC AND
HYDRAULIC COMBINED CIRCUIT
Electric and hydraulic combined circuit has the
following controls.
• Ride control (optional)
• Bucket positioner control
• Lift arm float control
• Lift arm kick-out control
• Lift arm auto-leveler upward control
(Optional)
• Lift arm auto-leveler downward control
(Optional)
T2-1-51
SYSTEM / Control System
Ride Control (Optional)
Purpose: Reducing fatigue of the operator by
organizing a damper circuit in the lift arm
cylinder and reducing shock in traveling on
rough roads
Operation:
1. When the ride control switch is turned ON, the MC
makes the ride control effective, and the ride
control indicator of the monitor is lit.
2. At vehicle speed of 7 km/h (4 mph) and above, the
MC receives signal from the vehicle speed sensor,
and transmits electric current to the ride control
solenoid valve.
3. When the ride control solenoid valve is operated
and the spool moves, a damper circuit is
organized between the rod end and the bottom
end of the lift arm cylinder. When the vehicle body
travels on bumpy roads, the fluctuation of the
bottom pressure of the lift arm cylinder is
absorbed by the ride control accumulator, and the
shock of the whole vehicle body is reduced.
NOTE: Ride control is not made at the vehicle
speed of 7 km/h (4 mph) and below.
NOTE: In case the ride control switch or the ride
control solenoid valve becomes out of order,
the ride control is not made.
T2-1-52
SYSTEM / Control System
Lift Arm Cylinder
ECM2
MC
ECM1
Transmission
To Control
Valve
Engine
Monitor
Unit
Vehicle Speed Sensor
Ride Control
Accumulator
OFF
ON
Ride Control
Switch
Ride Control
Indicator
Relief Valve
Ride Control Valve
Ride Control
Solenoid Valve
Spool
Pilot
Pump
Hydraulic Oil
Tank
T4HA-02-01-026
T2-1-53
SYSTEM / Control System
Bucket Auto-leveler Control
Purpose: Automatically tilting the bucket at an
appropriate angle (horizontal) to start
digging in returning the bucket to the tilting
position
Operation:
1. In dumping operation of the bucket, the bar is
located in front of the bucket proximity switch.
While the bar passes by the bucket proximity
switch, the bucket proximity switch becomes ON,
and excites the electromagnet on the bucket
tilting end of the pilot valve.
2. When the bucket operation lever is moved farther
than the bucket tilting detent position (position to
move farther than the tilting position), the bucket
operation lever is held by the electromagnet on
the bucket tilting end, and pressure oil from the
pilot valve moves the bucket spool of the control
valve.
3. Pressure oil from the main pump flows into the
bottom end of the bucket cylinder through the
bucket spool of the control valve, and extends the
buket cylinder. When the bucket cylinder is
extended, the bar also passes by the bucket
proximity switch.
4. When the bar becomes distant from the bucket
proximity switch, the bucket proximity switch is
turned OFF, and the electromagnet on the bucket
tilt end is also turned OFF, which makes the
bucket operation lever in the neutral position. As
the bucket spool of the control valve also returns
to neutral, the bucket cylinder stops. As a result,
the bucket is tilted at the right digging angle
(horizontal).
T2-1-54
SYSTEM / Control System
Bucket Cylinder
Bucket Proximity Switch
From #194 Terminal
of Fuse Box B
Bar
Control Valve
Pilot Valve
for Bucket
Electromagnet
on Bucket Tilting End
Bucket
Pilot
Pump
Lift Arm
Main
Pump
T2-1-55
Hydraulic Oil
Tank
T4GB-02-01-033
SYSTEM / Control System
Lift Arm Float Control
Purpose: Free raising and lowering of the lift arm in
response to the external load for snow
removing and road cleaning
Operation:
1. When the lift arm operation lever is moved to the
floating position (farther position than the lift arm
lowering position), the lift arm operation lever is
retained by the electromagnet on the lift arm
lowering end, and pressure oil from the pilot valve
moves the lift arm spool of the control valve up to
the floating position (farthest left position).
NOTE: When the engine is rotating, the
electromagnet on the lift arm lowering end
is always excited by the electric current
from #194 terminal of Fuse Box B.
2. Pressure oil from the main pump is blocked by the
lift arm spool, and ports on the rod end and the
bottom end of the lift arm cylinder are connected
through the lift arm spool, leading to the tank port.
As the both ports of the lift arm cylinder have the
same pressure as the hydraulic oil tank, the lift
arm cylinder is not restricted, allowing free
movement of the lift arm depending on the
external force.
3. Lift arm operation lever returns to neutral, if pulled
more strongly than the magnetic force of the
electromagnet. As the lift arm spool of the control
valve also returns to neutral, the lift arm floating
control is released.
T2-1-56
SYSTEM / Control System
Lift Arm Cylinder
Bottom End
Port
Rod End
Port
Control Valve
From #194 Terminal
of Fuse Box B
Electromagnet
on Lift Arm Lowering End
Bucket
Pilot Valve
for Lift Arm
Lift Arm
Pilot
Pump
Main
Pump
T2-1-57
Hydraulic Oil
Tank
T4GB-02-01-034
SYSTEM / Control System
Lift Arm Kick-out Control
Purpose: Automatically locating the lift arm at proper
height in returning the lift arm to the highest
position
Operation:
1. When lowering the lift arm, the plate is located in
front of the lift arm proximity switch.
While the plate passes by the lift arm proximity
switch, the lift arm proximity switch becomes ON,
and the electromagnet on the lift arm end is also
excited.
2. When the lift arm operation lever is moved farther
than the lift arm raising detent position (position to
pull farther than the raising position), the bucket
operation lever is retained by the electromagnet
on the lift arm raising end, and pressure oil from
the pilot valve moves the lift arm spool of the
control valve toward raising.
3. Pressure oil from the main pump flows into the
bottom end of the lift cylinder through the lift arm
spool of the control valve, and extends the lift arm
cylinder. When the lift arm cylinder is extended,
the plate also passes by the lift arm proximity
switch.
4. When the plate becomes distant from the lift arm
proximity switch, the lift arm proximity switch is
turned OFF, and the electromagnet on the lift arm
raising end is also turned OFF, which makes the
lift arm operation lever in the neutral position. As
the lift arm spool of the control valve also returns
to neutral, the lift arm cylinder stops. As a result,
the lift arm stops.
T2-1-58
SYSTEM / Control System
Plate
Lift Arm
Proximity Switch
Lift Arm
Cylinder
Bottom End
Port
Rod End
port
Control Valve
Bucket
From #194 Terminal
Fuse Box B
Pilot Valve
for Lift Arm
Electromagnet
for Lift Arm
End
Lift Arm
Pilot
Pump
Main
Pump
T2-1-59
Hydraulic Oil
Tank
T4GB-02-01-035
SYSTEM / Control System
Lift Arm Auto-leveler Upward Control (Optional)
Purpose: Free locating of the lift arm between the
horizon and the highest position
Operation:
1. If the SET position of the lift arm auto-leveler
upward set switch is selected after the lift arm is
located within the allowable location of the lift arm
auto-leveler (a’ in the illustration), signal from the
lift arm angle sensor is memorized by the MC,
and that is the lift arm auto-leveler upward
location.
NOTE: When the lift arm is outside a’, even if the
SET position of the lift arm auto-leveler
upward set switch is selected, setting of the
lift arm auto- leveler upward cannot be
made. In case setting was thus
unsuccessful, or setting in a different
position is needed, make setting again with
the above in mind.
3. Pressure oil from the main pump flows into the
bottom end port of the lift cylinder through the lift
arm spool of the control valve, and raises the lift
arm.
4. When the lift arm angle sensor moves up to the lift
arm auto-leveler upward locating position,
earthing of #241 terminal of the MC is released,
and the electromagnet on the lift arm upward end.
Thus the lift arm operation lever returns to the
neutral position, and supply of pressure oil from
the pilot valve to the control valve is stopped.
5. As the lift arm spool of the control valve also
returns to neutral, the lift arm stops at the lift arm
auto-leveler upward stop position.
NOTE: Above the lift arm upward set position, the
electromagnet on the lift arm raising end is
always excited.
a’ (Lift Arm
Auto-leveler
Upward
Allowable Setting
Range)
Position of
Lift Arm Foot Pin
NOTE: In case the lift arm angle sensor becomes
out of order, the lift arm auto-leveler upward
control is not made.
a (Lift Arm Upward
Work Range)
Position of
Lift Arm Tip Pin
IMPORTANT: In case either the lift arm angle
sensor or the MC has been replaced,
be sure to make learning control of
the lift arm angle sensor. (Refer to
the OPERATIONAL PERFORMANCE
TEST/Adjustment)
2. When the lift arm auto-leveler upward switch is
turned ON, #241 terminal of the MC is earthed,
and excites electromagnet on the lift arm upward
end of the pilot valve. When the lift arm operation
lever is moved farther than the lift arm upward
detent position (position to pull farther than the
upward position), the lift arm operation lever is
retained by the electromagnet on the lift arm
upward end, and pressure oil is supplied to the
control valve from the pilot valve.
T2-1-60
SYSTEM / Control System
Link
Lift Arm
Angle Sensor
Lift Arm
Cylinder
Bottom End
Port
Rod End
Port
Lift Arm
Auto-leveler
Upward Set Switch
OFF
SET
ON
Control Valve
234
238
MC
237
Bucket
241
Electromagnet
on Lift Arm Raising End
From #194 Terminal
of Fuse Box B
Lift Arm
Pilot Valve
for Lift Arm
Pilot
Pump
Main
Pump
T2-1-61
Hydraulic Oil
Tank
T4GB-02-01-036
SYSTEM / Control System
Lift Arm Auto-leveler Downward Control (Optional)
Purpose: Free locating of the lift arm between the
horizon and the lowest position
Operation:
1. If the SET position of the lift arm auto-leveler
downward set switch is selected after the lift arm
is located within the allowable location of the lift
arm auto-leveler (b’ in the illustration), signal from
the lift arm angle sensor is memorized by the MC,
and that is the lift arm auto-leveler downward
location.
NOTE: When the lift arm is outside b’, even if the
SET position of the lift arm auto-leveler
downward set switch is selected, setting of
the lift arm auto- leveler downward cannot
be made. In case setting was thus
unsuccessful, or setting in a different
position is needed, make setting again with
the above in mind.
3. Pressure oil from the main pump flows into the
rod end port of the lift cylinder through the lift arm
spool of the control valve, and lowers the lift arm.
4. When the lift arm angle sensor moves down to the
lift arm auto-leveler downwards locating position,
earthing of #242 terminal of the MC is released,
and the electromagnet on the lift arm downward
end is unexcited for a while until it is excited again
soon after.
5. Thus the lift arm operation lever returns to the
neutral position, and supply of pilot pressure from
the pilot valve to the control valve is stopped.
6. As the lift arm spool of the control valve also
returns to neutral, the lift arm stops at the lift arm
auto-leveler downward stop position.
NOTE: In case the lift arm angle sensor becomes
out of order, the lift arm auto-leveler
downward control is not made.
Position of
Lift Arm Tip Pin
Position of
Lift Arm Foot Pin
b’ (Lift Arm
Auto-leveler
Downward
Allowable Setting
Range)
b (Lift Arm Downward
Work Range)
IMPORTANT: In case either the lift arm angle
sensor or the MC has been replaced,
be sure to make learning control of
the lift arm angle sensor. (Refer to
the OPERATIONAL PERFORMANCE
TEST/Adjustment)
2. When the lift arm auto-leveler downward switch is
turned ON, #242 terminal of the MC is earthed,
and excites electromagnet on the lift arm
downward end of the pilot valve. When the lift arm
operation lever is moved to the lift arm downward
detent position (position farther than the
downward position), the lift arm operation lever is
retained by the electromagnet on the lift arm
downward end, and pressure oil is supplied to the
control valve from the pilot valve.
T2-1-62
SYSTEM / Control System
Link
Lift Arm
Angle Sensor
Lift Arm
Cylinder
Bottom End
Port
Rod End
Port
Lift arm
Auto-leveler Downward
Set Switch
OFF
SET
ON
234
Control Valve
240
MC
239
242
Bucket
Electromagnet on
Lift Arm Lowering End
Pilot Valve
for Lift Arm
From #194 Terminal
of Fuse Box B
Pilot
Pump
Lift Arm
T4GB-02-01-037
T2-1-63
SYSTEM / Control System
(Blank)
T2-1-64
SYSTEM / ECM System
OUTLINE
Signals from the various sensors installed at the
engine are transmitted to the ECM2 (Engine Control
Module 2) , and signal from MC (Main Controller) is
also transmitted to the ECM2 (Engine Control Module
2) through ECM1 (Engine Control Module 1).
ECM2 makes an arithmetic operation, and actuates the
solenoid valve of the unit pump to make the following
controls mostly for the injector.
• Fuel Injection Control
• Engine Preheat and Start Control (Refer to
SYSTEM/Electric System.)
• Engine Stop Control (Refer to SYSTEM/Electric
System.)
• Fuel low-pressure pump transfers fuel to the unit
pump of each cylinder of the engine.
• Unit pump is driven by the engine rotation, and
generates high-pressure fuel.
• Injector injects high-pressure fuel from the unit
pump.
• ECM2 cooler is installed on the ECM2. Cooling
the ECM2 with fuel prevents malfunctions of the
ECM2 due to heat generation.
Air Bleed Valve
Fuel Filter
Fuel Temperature Sensor
Solenoid
Valve
Fuel Filter
Drain Valve
Engine Oil Level Sensor
Crankshaft Angle Sensor
TDC (Top Dead Center)
Sensor
Coolant Temperature Sensor
Unit
Pump
Engine Oil Combination Sensor
(Temperature and Pressure)
Intake air Combination Sensor
(Temperature and Pressure)
Injector
Engine Start Switch
Engine Stop Switch
Bypass Valve
Relief Valve
Fuel Low-pressure
Pump
MC
Overflow
Valve
Orifice
CAN
(Vehicle Body
Network)
ECM2
Manual
Pump
Fuel Tank
ECM1
T4HA-02-02-001
ECM2 Cooler
T2-2-1
SYSTEM / ECM System
FUEL INJECTION CONTROL
• At start of the engine, the ECM2 (Engine Control
Module 2) grasps the engine operating condition
by the signal from each sensor.
• ECM2 makes an arithmetic operation when a
signal from the MC (target engine speed
command) enters the ECM2.
• ECM2 transmits signal to the solenoid valve of the
unit pump for injecting fuel from the injector.
• ECM2 always compensates strength and time of
the signal to be transmitted to the unit pump for
effectively increasing the engine speed to the
target value in response to the engine operating
condition.
• ECM2 controls injection time and injection
pressure of the fuel injected from the injector by
compensating strength and time of the signal sent
to the unit pump from the ECM2.
• This realizes supply of stable output, restricting
redundant use of fuel and occurrence of nitrogen
oxide (NOx).
NOTE: Engine body is provided with the engine
start switch and engine stop switch, and
start and stop of the engine is possible at
site during engine inspection or something.
NOTE: Mode switches of the work mode switch
are supplied with respectively different
voltages from the monitor unit. MC judges
the selected mode by the supplied voltage.
NOTE: Two switches are installed inside the shift
switch, and the turning ON condition varies
depending on the combination of speed
shifts. MC judges the selected speed shift
by the combination of two input currents.
T2-2-2
SYSTEM / ECM System
Accelerator
Pedal Sensor
Accelerator
Pedal
Work Mode
Select Switch
L
N
P
Shift Switch
MC
Monitor
Unit
Vehicle Speed
Sensor
Engine
Cooling Water
Temperature
Sensor
ECM1
Air Bleed Valve
Fuel Filter
Fuel Temperature Sensor
Solenoid
Valve
Fuel Filter
Drain Valve
Engine Oil Level Sensor
Crankshaft Angle Sensor
Unit Pump
TDC (Top Dead Center)
Sensor
Coolant Temperature Sensor
Engine Oil Combination
Sensor (Temperature
and Pressure)
Intake Air Combination
Sensor (Temperature and
Pressure)
Engine Start Switch
Engine Stop Switch
Injector
Bypass Valve
Relief Valve
Fuel Low-pressure
Pump
Overflow
Valve
Orifice
Manual
Pump
Fuel Tank
ECM2
T4HA-02-02-002
ECM2 Cooler
T2-2-3
SYSTEM / ECM System
Fuel Injection
4. After Injection Process
When the ECM2 stops signal to the solenoid
valve of the unit pump, the solenoid valve is
unexcited, and the valve is opened.
Pressure in the high-pressure chamber lowers
rapidly, and fuel injection from the injector is
stopped.
Piston is further pressurized in accordance with
the camshaft movement, and the fuel in the
high-pressure chamber is discharged to the
suction chamber through the clearance of the
valve.
Inlet of the unit pump is always supplied with fuel
from the fuel low-pressure pump through the fuel filter,
and the fuel uninjected returns to the fuel tank.
Fuel is injected from the injector by the reciprocating
movement of the piston inside the unit pump moving
in unison with rotation of the cam shaft and by the
movement of the solenoid valve and the valve
operated excited by the signal from the ECM2
(Engine Control Module 2).
1. Sucking Process
When a cylinder of the engine is in the sucking
process, the piston of the unit pump also lowers.
Valve is opend by the force of the valve spring
because the solenoid valve is not excited.
Fuel in the suction chamber of the unit pump is
sucked into the high-pressure chamber through
the clearance of the valve.
IMPORTANT: Unit pump and the injector do not
contain
parts
replaceable
for
disassembly and adjustment, so be
sure to replace the whole assembly,
when necessary.
2. Before Injection Process
When the engine cylinder is in the compression
process, the piston of the unit pump also begins
to rise. But as injection of fuel from the injector is
not necessary yet, the fuel sucked into the
high-pressure chamber is discharged to the
suction chamber throught the clearance of the
valve by the amount the piston has stroked.
3. Injection Process
In the engine cylinder process of compression
immediately before the TDC, when the ECM2
transmits signal to the solenoid valve, the valve of
the unit pump is closed. As the piston continues
rising even after the valve is closed, the pressure
in the high-pressure chamber steeply rises, and
fuel is injected from the injector.
Pressure in the high-pressure chamber rises as
high as 180 MPa (1836 kgf/cm2) at the maximum.
T2-2-4
SYSTEM / ECM System
1. Suction Process
2. Before Injection Process
Injector
Valve
Valve
Valve Spring
Suction
Chamber
Suction
Chamber
Solenoid Valve
From Fuel
Low-pressure
Pump
To Fuel Tank
From Fuel
Low-pressure
Pump
To Fuel Tank
High-pressure
Chamber
High-pressure
Chamber
Piston
Piston
Cam Shaft
3. Injection Process
4. After Injection Process
Injector
Injector
Valve
Valve
Solenoid Valve
Suction
Chamber
Solenoid Valve
Signal from
ECM2 for
Excitement
From Fuel
Low-pressure
Pump
To Fuel
Tank
From Fuel
Low-pressure
Pump
High-pressure
Chamber
To Fuel
Tank
High-pressure
Chamber
Piston
Piston
Cam Shaft
Cam Shaft
T4HA-02-02-003
T2-2-5
SYSTEM / ECM System
(Blank)
T2-2-6
SYSTEM/Hydraulic System
OUTLINE
Hydraulic system is broadly be divided into the main
circuit, pilot circuit, steering circuit, and hydraulic
drive fan circuit.
• Main Circuit
Main circuit consists of the priority valve circuit,
neutral circuit, single operation circuit, and
combined operation circuit – composed of the
main pump, priority valve, control valve, cylinders,
etc.
• Pilot Circuit
Pilot circuit consists of the charging block circuit,
front attachment operation control circuit, pump
control circuit, brake circuit, and ride control circuit
(optional) – composed of the pilot pump, charging
block and valves for controlling each circuit.
• Steering Circuit
Steering circuit consists of the normal steering
circuit,
steering
shock
damping
circuit,
emergency steering circuit (optional), steering
stop circuit– composed of the pump, priority valve,
steering valve, cylinders, and other valves.
• Hydraulic Drive Fan Circuit
Hydraulic drive fan circuit consists of the flow
control circuit and reverse rotation control circuit –
composed of the motor for radiator cooling fan
and the pump for radiator cooling fan.
NOTE: Steering circuit can be divided into the main
circuit and the pilot circuit, but is described
here as an single circuit for making
explanation clear.
T2-3-1
SYSTEM/Hydraulic System
MAIN CIRCUIT
Outline
• Main pump draws hydraulic oil, from the hydraulic
oil tank through the suction filter and delivers.
• Delivered pressure oil flows to the steering valve
and the control valve through the priority valve.
• Pressure oil led to the steering valve flows to the
steering cylinders in response to operation of the
spool in the steering valve and the return oil flows
back to the hydraulic oil tank through the steering
valve.
• Pressure oil led to the control valve flows to the
cylinders in response to operation of the spool in
the control valve, and the return oil flows back to
the hydraulic oil tank through the control valve.
T2-3-2
SYSTEM/Hydraulic System
Bucket Cylinder
Steering Cylinders
Lift Arm Cylinders
Control Valve
Bucket
Spool
Steering
Valve
Lift Arm
Spool
Priority
Valve
Main Pump
Suction
Filter
Hydraulic oil
Tank
T4GB-02-02-010
T2-3-3
SYSTEM/Hydraulic System
Priority Valve Circuit
• At stop of the engine, the priority valve spool is
• When pressure at Port LS2 and the spring force
pushed leftward, by the spring force.
• When the engine is started, pressure oil from the
main pump flows toward the steering valve
through the priority valve spool, while also
entering Ports LS1 and LS2 through Orifices 1
and 2 respectively.
• At neutral of the steering valve, pressure oil led to
Port LS2 flows to the hydraulic oil tank through
Orifice 3 and the steering valve spool, so Port LS2
is not pressurized.
• As pressure at LS1 causes larger force than the
spring force, the priority valve spool moves right,
and pressure oil from the main pump is all
supplied to the control valve.
• Priority valve spool is provided with a notch for
leading pressure oil from the main pump toward
the steering valve and a notch for leading
pressure oil from the main pump toward the
control valve, which are both connected to the
main pump delivery port constantly.
• When the priority valve spool moves right, the
notch for leading pressure oil from the main pump
toward the steering valve moves until the delivery
port on the steering valve side in the priority valve
is closed. When pressure balance is obtained and
the spool stops moving.
• When the steering valve spool moves, the tank
port connected with Port LS2 is closed.
• At this time, Port LS2 is connected with the main
circuit through the steering valve spool, and
pressure corresponding to movement of the
steering valve spool arises at Port LS2.
overcome pressure at Port LS1, the priority valve
spool moves left.
• Larger the movement of the steering valve spool
is, the higher the pressure at Port LS2 rises, the
larger the priority valve spool moves left, and the
more pressure oil from the main pump is supplied
to the steering valve.
T2-3-4
NOTE: Orifice 2 of the priority valve is installed for
warming up the circuit by flowing pressure
oil to the hydraulic oil tank from Port LS2 at
neutral of the steering valve. Diameter of
Port 2 is small, and temperature of the oil
passing through it rises rapidly, but
pressure is not raised enough to influence
movement of the priority valve spool.
SYSTEM/Hydraulic System
Bucket Cylinder
Steering Cylinders
Lift Arm
Cylinders
Steering Valve
Control Valve
Hydraulic
Oil Tank
Bucket
Spool
Hydraulic
Oil Tank
Lift Arm
Hydraulic
Oil Tank
Priority
Valve
Spring
Orifice1
Orifice 1
Orifice 3
LS1
Spool
LS2
At Stop of Engine
Main Pump
NOTE: Illustration shows oil flow in idling operation
while the engine is rotating.
T2-3-5
T4HA-02-03-001
SYSTEM/Hydraulic System
Neutral Circuit
• At neutral position of the control lever, pressure oil
from the main pump returns to the hydraulic oil
tank through the neutral circuit of the control
valve.
• Only when the steering valve spool moves
actuated by the priority valve, pressure oil is
supplied to the steering valve, the steering valve
is not provided with a neutral circuit. (Refer to
Priority Valve Circuit in this section.)
Single Operation Circuit
• Pressure oil from the main pump enters the
control valve, and flows to the lift arm and bucket
spools.
• When the steering valve spool moves, the priority
valve spool moves left, and pressure oil from the
main pump flows to the steering valve. (Refer to
Priority Valve Circuit in this section.)
T2-3-6
SYSTEM/Hydraulic System
Bucket Cylinder
Steering Cylinders
Lift Arm
Cylinders
Steering Valve
Control Valve
Hydraulic
Oil Tank
Bucket
Spool
Hydraulic
Oil Tank
Lift Arm
Hydraulic
Oil Tank
Priority
Valve
Spool
Main Pump
T4HA-02-03-002
NOTE: Illustration shows oil flow in idling operation
while the engine is rotating.
T2-3-7
SYSTEM/Hydraulic System
Combined Operation Circuit
• Lift Arm Raising/Bucket Dumping
• When the bucket is dumped with the lift arm
raised, pilot pressure shift the lift arm and bucket
spools in the control valve.
• Also, the same pilot pressure that changed the lift
arm spool in the control valve shifts the selector
valve spool downward as well.
• Pressure from the own pump is applied to Port
LS1 of the priority valve, but Port LS2 is not
pressurized because it is connected to the
hydraulic oil tank.
• Pressure at Port LS1 causes larger force than the
spring force of the priority valve, and moves the
spool right.
• By movement of the spool, pressure oil from the
main pump flows to the lift arm cylinders through
the check valve in the control valve and the lift
arm spool, and raises the lift arm.
• Pressure oil from the main pump also flows to the
bucket cylinder though the flow rate control valve
in the control valve and the bucket spool, and
dumps the bucket.
• Lift arm raising operation is more heavy loaded
than the bucket dumping operation, but pressure
inside the spring chamber rises in the bucket
dumping operation because shift of the selector
valve is over.
• Raised pressure in the spring chamber prevents
the flow rate control valve from moving much, and
flow of pressure oil to the bucket spool is
restricted.
• As a result, flow rate to the lift arm cylinders is
secured, causing smooth operation of the lift arm
cylinders and bucket cylinder.
T2-3-8
SYSTEM/Hydraulic System
Steering Cylinders
Bucket Cylinder
Lift Arm
Cylinders
From Pilot Valve
(Bucket Damp)
Flow Rate
Spring
Control Valve Chamber
Steering Valve
Control Valve
Bucket
Hydraulic
Oil Tank
From Pilot Valve
(Lift Arm Raise)
Lift Arm
Selector Valve
From Pilot Valve
(Lift Arm Raise)
Check Valve
Priority
Valve
Hydraulic
Oil Tank
Spring
LS2
LS1
Spool
Main Pump
T4GB-02-02-018
T2-3-9
SYSTEM/Hydraulic System
• Lift Arm Raising/Steering right
• When the steering wheel is turned right with the
lift arm raised, pilot pressure shifts the lift arm
spool in the control valve and the steering valve
spool.
• Pressure from the own pump is applied to Port
LS1 of the priority valve through Orifice 1, and
main pressure returning from the steering valve
spool through Orifice 3 and the spring force are
applied to Port LS2.
• Pressure at Port LS2 changes in proportion to the
steering valve spool stroke, and when pressure at
Port LS2 is low, the priority valve spool moves left
slightly, and when it is high, the spool moves left
drastically.
• Flow rate and direction of the main pump are
controlled by the leftward stroke of the priority
valve spool, and the flow rate corresponding to
the stroke flows to the steering valve, and the
remainder flow rate flows to the control valve.
NOTE: When the steering wheel is turned quickly
and largely for reasons of avoiding danger
or something, the priority valve spool
largely moves left, and much of the
pressure oil from the main pump is
supplied to the steering valve, delaying
movement of the front attachment.
• Pressure oil led to the steering valve flows to the
steering cylinders, and the vehicle body turns
right.
• Pressure oil led to the control valve also flows to
the lift arm cylinders though the check valve and
the lift arm spool, and raises the lift arm.
• In this way, steering and lift arm operations are
simultaneously made.
T2-3-10
SYSTEM/Hydraulic System
Bucket Cylinder
Steering Cylinders
Lift Arm
Cylinders
Steering Valve
Control Valve
Hydraulic
Oil Tank
From Steering
Pilot Valve
(Right Steering)
Bucket
Spool
Hydraulic
Oil Tank
Lift Arm
From Pilot
Valve
(Left Arm
Raise)
Check Valve
Hydraulic
Oil Tank
Priority Valve
Spring
Orifice 2
Orifice 1
Orifice 3
LS1
Spool
LS2
Main Pump
T4GB-02-02-019
T2-3-11
SYSTEM/Hydraulic System
(Blank)
T2-3-12
SYSTEM/Hydraulic System
PILOT CIRCUIT
Outline:
Pressure oil from the pilot pump is used to operate the
circuit below.
• Charging Block Circuit
• Front Attachment Operation Control Circuit
• Pump Control Circuit
• Brake Circuit
• Ride Control Circuit (Optional)
Front Attachment
Control Circuit
Pilot Shutoff
Valve
Lift Arm Pilot
Valve
Bucket Pilot
Valve
Optional Pilot
Valve
Control Valve
Brake
Valve
Service
Brake
Brake Circuit
Parking
Brake
Charging Block
Main Pump
Regulator
Pump Control Circuit
Spool
Ride Control Circuit
(Optional)
Ride
Control
Solenoid
Valve
Ride Control Valve
Charging Block Circuit
Pilot
Filter
Pilot
Pump
Suction
Filter
Hydraulic
Oil
Tank
T4GC-02-02-001
T2-3-13
SYSTEM/Hydraulic System
Charging Block Circuit
• Charging block is installed for supplying pressure
oil from the pilot pump preferentially to the service
brake circuit, while distributing it to other pilot
circuits as well.
• When the engine is started, oil is delivered from
the pilot pump, and enters the charging block.
• At this time, when the amount of accumulated
pressure of the service brake accumulators is low,
the relief valve is closed.
• In this case, only pilot pressure is applied to Port
B of the priority valve, but both the pilot pressure
and the spring force are applied to Port A. So, the
priority valve moves right, restricting pressure oil
to flow further.
• Pressure oil from the pilot pump flows toward the
service brake circuit through the check valve, and
accumulates the service brake accumulators.
(to be continued to T2-3-16)
NOTE: Spring of the priority valve is so adjusted
that the valve is not completely closed.
Even in the minimum opening condition, a
certain amount of pressure oil is being
supplied to the circuits downstream.
T2-3-14
SYSTEM/Hydraulic System
Service Brake
Brake
Valve
Front Brake
Service Brake
Accumulators
Brake
Valve
Rear Brake
Check
Valves
Relief Valve
B
Priority
Valve
A
Spring
Charging Block
Pilot Pump
NOTE: Illustration shows oil flow when the priority
valve is closed in response to pressure
decrease in the service brake circuit.
T2-3-15
T4GC-02-02-002
SYSTEM/Hydraulic System
• When the service accumulators are pressurized
to a certain amount, the relief valve opens, and
pressure is lost because Port A of the priority
valve is connected to the hydraulic oil tank.
• Pressure at Port B of the priority valve causes
larger force than the spring force, and moves the
priority valve spool left. So, pressure oil from the
pilot pump is all supplied to the priority valve and
the circuits downstream.
• Pressure oil from the priority valve is supplied
through each port to the respective pilot circuits.
• When pressure in the pilot circuit rises higher than
a certain amount, the pilot relief valve opens, and
prevents components of the pilot circuit from
being damaged.
• Pressure oil from Port PS1 passes the steering
pilot valve to be supplied for actuation of the
steering valve spool. (Refer to Steering Circuit.)
• Pressure oil from Port X changes its flow in
response to the stroke of the pump torque
control solenoid valve which is controlled by the
signal from MC, and is used for controlling the
main pump regulator.
(Refer to Pump Control Circuit.)
• Pressure oil from Port BR3 is supplied for parking
brake release pressure by operation of the
parking brake solenoid valve. (Refer to Parking
Brake Circuit)
• Pressure oil from Port PS2 is supplied for
controlling the servo piston of the main pump
(Refer to Pump Control Circuit.) and the spool of
the ride control valve (Refer to Ride Control
Circuit.).
• Pressure oil from Port PP enters each pilot valve
through the pilot shutoff valve, and is supplied to
the control valve for actuation of the spool. (Refer
to Front Attachment Operation Control Circuit.)
T2-3-16
SYSTEM/Hydraulic System
Bucket
Pilot Valve
Lift Arm
Pilot Valve
Spare Pilot
Valve (Optional)
Pilot Shutoff Valve
To Service Brake
Circuit
Service Brake
Accumulators
Priority Valve
Relief Valve
B
Pilot Pump
Pilot
Relief Valve
Hydraulic Oil Tank
PS1
A
Spring
X
Pump Torque Control
Solenoid Valve
BR3
PS2
Parking Brake
Pressure Sensor
Parking Brake
Solenoid Valve
PP
Charging Block
NOTE: Illustration shows the oil flow in neutral
condition of the pilot valve when the service
brake accumulators are pressurized, the
priority valve is open, and the pilot shutoff
valve is open.
T2-3-17
T4GB-02-02-020
SYSTEM/Hydraulic System
Front Attachment Operation Control Circuit
• Pressure oil from the pilot pump flows the
charging block, and comes out of Port PP of the
charging block to be supplied to each pilot valve
through the pilot shutoff valve.
• Priority valve of the charging block supplies
pressure oil preferentially to the service brake
circuit when pressure in the service brake
accumulators are lowered. (Refer to Charging
Block Circuit.)
• Pilot shutoff valve is a manually operated type,
and is installed for prevention of accidents due to
mistaken operation by stopping suppy of pressure
oil to the pilot valve when it is closed.
• By controlling each pilot valve, pressure oil from
the pilot pump shifts the control valve spool.
• At both ends of the spool for the lift arm cylinders
of the control valve, slow-return valves are
installed for moderating sudden movement of the
spool.
T2-3-18
SYSTEM/Hydraulic System
Bucket
Pilot Valve
Lift Arm
Pilot Valve
1
3
2
4
Spare Pilot
Valve (Optional)
5
6
7
8
Control Valve
Pilot Shutoff Valve
8
Spare 2
7
To Service Brake
Circuit
Service Brake
Accumulators
6
Priority Valve
2
Spare 1
5
Bucket
1
Pilot Pump
4
Slow-Return
Valves
Lift Arm
3
Main Pump
PP
Charging Block
T4GB-02-02-021
NOTE: Numeral of each port of the pilot valves and
the control valve shows the port to be
connected.
Illustration shows the oil flow in neutral
condition of the pilot valve when the service
brake accumulators are pressurized, the
priority valve is open, and the pilot shutoff
valve is open.
T2-3-19
SYSTEM/Hydraulic System
Pump Control Circuit
(Refer to COMPONENT OPERATION / Pump
Device group)
• Pump Control by Servo Piston Control Pressure
• Servo piston control pressure (PS2) is supplied
from the charging block for actuation of the servo
piston of the main pump.
• Pump Flow Rate Control by Flow Rate Control
Pressure (Pi1/Pi2)
• Pressures upward and downward the orifice – Pi1
and Pi2 – of the pump flow rate control valve
installed at the farthest downstream of the control
valve neutral circuit are supplied to the main
pump regulator for adjusting the pump flow rate.
• Pump Flow Rate Control by Pump Torque Control
Solenoid Valve
• Signal from MC actuates the pump torque control
solenoid valve, and controls the pressure (X)
supplied to the main pump regulator for
controlling the pump flow rate.
T2-3-20
SYSTEM/Hydraulic System
Charging Block
Pilot Pump
Pump Torque Control
Solenoid Valve
Hydraulic Oil Tank
Command Signal from MC
Pilot Presser (X)
PS2
Orifice
Pump From Control Valve
Control Valve
Pi2
Pi1
Main Pump
Main Pump
Regulator
Servo
Piston
T4HA-02-03-003
T2-3-21
SYSTEM/Hydraulic System
Brake Circuit
Service Brake Circuit
(Refer to COMPONENT OPERATION / Charging
Block)
(Refer to COMPONENT OPERATION / Brake
Valve)
• Pressure oil from the pilot pump flows through the
charging block, and is accumulated in the service
brake accumulators.
• By stepping the brake pedal, pressure in the
service brake accumulators is applied to the front
brake and the rear brake through the brake valve,
and actuates the service brake.
• When the brake pedal is stepped several times,
pressure inside the service brake accumulators is
lowered, and the relief valve is closed.
• Priority valve spool moves right, and pressure in
the service brake accumulators is kept constant
by preferentially supplying pressure oil from the
pilot pump to the service brake circuit, and firmly
brakes the vihicle.
Parking Brake Circuit
• Pressure oil from the pilot pump is applied to the
parking brake solenoid valve through the charging
block.
• When the parking brake is switched OFF, the
parking brake solenoid valve is excited, and
pressure oil entering the parking brake cylinder
releases the parking brake.
• If the parking barke is switched ON, the parking
brake solenoid valve is unexcited, and resultant
stop of pressure oil supply to the parking brake
causes working of the parking brake.
• Even if pressure is lowered caused by damage of
hose or something in the upstream of the solenoid
valve, the parking brake accumulators so function
as to retain the parking brake circuit pressure for
a certain period of time.
NOTE: Spring of the priority valve is so adjusted
that the valve is not completely closed.
Even in the minimum opening condition, a
certain amount of pressure oil flow is being
supplied to the circuits downstream.
NOTE: Even when the engine is stopped, the
service brake circuit pressure is retained
for a while with the functions of the service
brake accumulators and the check valve.
T2-3-22
NOTE: Parking brake is released when the
solenoid valve is excited.
SYSTEM/Hydraulic System
Service Brake
Brake
Pedal
Front Brake
Service Brake
Accumulators
Brake
Valve
Rear Brake
Check
Valves
Relief Valve
Priority
Valve
Spring
Parking Brake
Pressure Sensor
Parking
Brake
Solenoid
Valve
Parking Brake
Release
Pilot
Accumulator
No Signal for
Parking Brake
Release
Brake
Charging Block
Pilot Pump
NOTE: Illustration shows oil flow when the relief
valve and the priority valve are open in
response to pressure increase in the
service brake circuit, and also oil flow when
the parking brake is working with the
unexcitement of the parking brake solenoid
valve.
T2-3-23
T4GC-02-02-003
SYSTEM/Hydraulic System
Ride Control Circuit (Optional)
(Refer to SYSTEM / Electric-Hydraulic Combined
Circuit Control in Control System)
• In front attachment operation, operating pressure
from the lift arm cylinders is accumulated in the
ride control accumulator through the charge cut
spool.
• When the ride control switch is turned ON, the
ride control solenoid valve is excited, and the
spool moves downward.
• Bottom end of the lift arm cylinders is connected
with the ride control accumulator, while the rods
side end of the lift arm cylinders is connected to
the hydraulic oil tank.
• In this way, force to raise the front attachment is
relieved to the hydraulic oil tank, and force to
lower the front attachment is absorbed by the ride
control accumulator, thus enabling stable
traveling on rough roads.
T2-3-24
SYSTEM/Hydraulic System
Ride Control
Accumulator
Lift Arm Cylinders
To Control
Valve
Ride Control Valve
Ride Control
Command Signal
Ride Control
Solenoid Valve
Spool
Charge Cut
Spool
Hydraulic Oil Tank
Pilot
Pump
NOTE: Illustration shows oil flow when the ride
control solenoid valve is excited.
T2-3-25
T4GB-02-02-009
SYSTEM/Hydraulic System
STEERING CIRCUIT
Normal Steering Circuit
• Normally, pressure oil from the main pump flows
to the steering valve through the priority valve, but
is not pressurized because the pilot line (LS2) is
led to the hydraulic oil tank.
• Therefore, pressure oil is all supplied to the
control valve because the priority valve spool is
shifted to the right pushed by pressure (LS1) from
the own main pump large enough to overcome
the spring force of the priority valve.
• When the steering wheel is turned, the spool in
the steering pilot valve is shifted, and pressure oil
from the pilot pump moves the steering valve
spool.
• When the steering wheel is quickly turned, a large
amount of pilot pressure oil is supplied in a short
period of time to the end of the steering valve
spool through the steering pilot valve, and the
steering valve spool moves quickly and largely.
• When the steering wheel is slowly turned, a small
amount of pilot pressure oil is supplied gradually
to the end of the steering valve spool through the
steering pilot valve, and the steering valve spool
moves slowly and slightly.
• In proportion to the stroke of the steering valve
spool, pressure in the pilot line (LS2) rises, and
the priority valve spool is pushed left by the spring
force of the priority valve and pressure of the pilot
line (LS2).
• In this way, pressure oil from the main pump flows
to the steering cylinders through the priority valve
and the steering valve, and the steering cylinders
are
actuated.
(Refer
to
COMPONENT
OPERATION / Pump Device)
T2-3-26
NOTE: When pressure oil passes inside the
steering pilot valve, it flows to the steering
valve after passing the Gerotor part.
Gerotor is connected with the middle shaft
of the pilot steering valve, so powered
steering effect is generated. (Refer to
COMPONENT OPERATION / Steering
Pilot Valve)
SYSTEM/Hydraulic System
Steering Cylinders
Steering
Accumulators
Steering Valve
Hydraulic Oil Tank
Spool
Orifice
Orifice
Pump
Discharge Pressure
Switch
Steering
Pilot
Valve
To Control
Valve
Gerotor
Spool
Priority
Valve
Spring
Emergency
Steering
Pump Equipment
LS2
Steering
Wheel
LS1
Pilot
Pump
Hydraulic
Oil Tank
Main Pump
NOTE: Illustration shows flow of pressure oil when
the steering wheel is turned right.
T2-3-27
T4GB-02-02-023
SYSTEM/Hydraulic System
Steering Shock Damping Circuit
• Pressure of the pressure oil supplied from the
steering pilot valve to the spool end of the
steering valve is reduced by passing through the
orifice inside the steering valve, and is applied to
the spool end of the opposite side. In this way, the
vehicle shock due to sudden shift of the spool is
damped, and stable steering operation is possible.
(Refer to COMPONENT OPERATION / Steering
Valve)
• Steering accumulators are provided for damping
the joggling of the vehicle taking place at stop of
the steering wheel rotation.
Emergency Steering Circuit (Optional)
• When traveling, if the main pump delivery is
stopped or drastically decreased caused by
failure of the engine or the main pump, the signal
of the pump delivery pressure swithc is
transmitted into the monitor controller, and the
monitor controller starts the motor of the
emergency steering pump equipment.
• Pressure oil is supplied from the emergency
steering pump for 1 minute, and steering
operation is possible.
• When 1 minute have passed or when the key
switch has been turned OFF after moving the
vehicle to a safe place, the emergency steering
pump stops.
NOTE: When engine is started, the monitor unit
automatically
starts
the
emergency
steering pump unit to confirm its function.
When the pressure sensing signal of the
emergency
steering
pump
delivery
pressure switch enters the monitor unit, the
emergency
steering
pump
unit
automatically stops. (EU Model Only)
T2-3-28
SYSTEM/Hydraulic System
Steering Cylinders
Steering
Accumulators
Steering Valve
Spool
Orifice
Orifice
Pump
Delivery Pressure
Switch
Steering
Pilot
Valve
To Control
Valve
Gerotor
Spool
Priority
Valve
Spring
Emergency
Steering
Pump Delivery
Pressure Switch
Emergency
Steering
Pump Equipment
LS2
Steering
Wheel
LS1
Pilot
Pump
Main Pump
NOTE: Illustration shows flow of pressure oil when
the steering wheel is turned right.
T2-3-29
T4GB-02-02-023
SYSTEM/Hydraulic System
Steering Stop Circuit
(Refer to COMPONET OPERATION / Steering
Valve)
• When either of the left or right cylinder is at the
• As a result, the steering valve spool is shifted at
stroke end, the stop valve spool contacts the
frame, and the stop valve closes to block
pressure oil from being supplied to the steering
valve from the steering pilot valve.
neutral, and supply of pressure oil from the main
pump to the steering cylinders is stopped.
Steering Cylinders
Steering Valve
Spool
Stop
Valve
Stop
Valve
External Force
Applied
Steering
Pilot Valve
Main Pump
Pilot Pump
Hydraulic
Oil Tank
T4GB-02-02-00
NOTE: Illustration shows flow of oil when the
steering valve is turned right.
T2-3-30
SYSTEM/Hydraulic System
(Blank)
T2-3-31
SYSTEM/Hydraulic System
HYDRAULIC DRIVE FAN CIRCUIT
(Refer to COMPONET OPERATION / Others)
(Refer to COMPONET OPERATION / Hydraulic Fan
Motor)
• Pressure oil from the fan pump flows to the fan
motor for radiator cooling through the flow control
valve and the reverse rotation spool.
• Electric current corresponding to the oil
temperature is sent from MC to the flow control
solenoid valve.
• Pressure oil is supplied to the flow control valve
spool end in response to the stroke of the flow
control solenoid valve, when it is excited.
• When the flow control valve is operated, pressure
oil from the fan pump to the fan motor is restricted,
and speed of the fan motor is controlled.
• When the fan reverse rotation switch is turned ON,
electric current flows from MC to the reverse
rotation control solenoid valve.
• When the reverse rotation control solenoid valve
is operated, pressure oil is supplied to the reverse
rotation spool end.
• When the reverse rotation spool is shifted, the
inlet port of pressure oil supplied to the fan motor
is shifted, and the fan motor rotates reversely.
T2-3-32
SYSTEM/Hydraulic System
Fan Motor
Reverse Rotation Spool
Reverse Rotation Control
Solenoid Valve
Reverse Rotation
Signal from MC
Flow Control Valve
Flow Control Solenoid Valve
Hydraulic oil
Tank
Hydraulic oil
Tank
Fan Pump
Flow Adjustment
Signal from MC
NOTE: Illustration shows flow of pressure oil
controlling nothing.
T2-3-33
T4GB-02-02-008
SYSTEM/Hydraulic System
(Blank)
T2-3-34
SYSTEM/Electric System
OUTLINE
Electric circuit can largely be divided into the main
circuit part, lamplight circuit and control circuit
• Main Circuit
Circuit for engine start/stop, circuit for battery
charging, and circuit for accessories
• Lamplight Circuit
Circuit for use in traveling (composed of head lights,
turn signals, brake lights, and horn)
• Control Circuit (Refer to the SYSTEM/Control
System.)
Control circuit for engine, pumps, transmission, and
valves [composed of actuators like solenoid valves,
MC (main controller), ECM1 and 2 (engine control
module), ICF (information controller), monitor unit,
switches, sensors, and pressure switches]
In this chapter, functions and compositions of the main
circuit and lamplight circuit are explained.
T2-4-1
SYSTEM/Electric System
MAIN CIRCUIT
• Electric Power Circuit: for supplying electricity to
the electric system as power source
• Indicator Light Check Circuit: for checking monitor
warning lamps and indicators
• Accessory Circuit: for working at ACC of the key
switch
• Preheat Circuit: for assisting engine start in chilly
weather
• Starting Circuit: for starting engine
• Charging Circuit: for supplying electricity to the
battery and replenishing electricity
• Surge Voltage Prevention Circuit: for preventing
occurrence of surge voltage at stop of the engine
• Engine Stop Circuit: for stopping the engine by
the ECM
T2-4-2
SYSTEM/Electric System
ELECTRIC
POWER
SWITCH:OFF)
CIRCUIT
(KEY
Ground terminal of the battery is earthed to the base
machine. Electric current from the plus terminal flows
as follows at OFF of the key switch.
→
Even at OFF of the key switch, very small amount of
electric current is being supplied to the circuit, so the
ground terminal of the battery needs to be
disconnected in case of a long downtime.
#6 Terminal
Key Switch
Head Light Switch
Battery
↓
Fusible
Link
→ Fuse Box B
→
#11 Terminal
→
#9 Terminal
Load Dump Relay
→
#2 Terminal
GPS
Flasher Relay
ICF
MC
Optional Control Unit (Optional)
→
#7 Terminal
ECM Relay
→
#37 Terminal
Interior Light
Radio
MC
→
→
#381 Terminal
#711 Terminal
Optional Control Unit (Optional)
Monitor Unit
Head Light Switch
Key Switch
Fuse Box B
348
149
126
6
11
9
35
158
127
654
2
7
39
42
37
381
711
Fusible
Link
Battery
Relay
638
34
263
70
710
75
Battery
T4HA-02-04-003
T2-4-3
SYSTEM/Electric System
INDICATOR LIGHT CHECK CIRCUIT (KEY
SWITCH:ON)
• When the key switch is turned ON, Terminal B is
• Monitor unit checks warning lamps and indicators
connected inside the key switch to ACC and
Terminal M.
• Electric current from Terminal M of the key switch
is enters #67 Terminal of the monitor unit.
by lighting them, and also starts the liquid crystal
display.
Key Switch
Fuse Box B
Monitor Unit
67
Fusible
Link
348
149
577
327
222
323
6
11
9
35
158
127
654
2
838
711
75
Battery
Relay
148
126
638
34
263
Battery
T4HA-02-04-011
T2-4-4
SYSTEM/Electric System
ACCESSORY CIRCUIT
• At ACC of the key switch, Terminal B is connected
inside the key switch to Terminal ACC.
• Electric current from Terminal ACC of the key
switch enters #3 Terminal of the radio through #34
and #35 Terminals of Fuse Box B, enabling the
radio to work.
Key Switch
Fuse Box B
348
149
577
327
222
323
6
11
9
35
158
127
654
838
711
75
Battery
Relay
Battery
Radio
Fusible
Link
148
126
638
34
T4GB-02-03-003
T2-4-5
SYSTEM/Electric System
PREHEAT CIRCUIT (KEY SWITCH:ON)
• When the key switch is turned ON, Terminal B is
connected inside the key switch to Terminal M.
• Part of the electric current from Terminal M flows
to the glow relay, and the remainder excites the
battery relay through #54 and #55 Terminals of
Fuse Box A, and the battery power source
supplies electricity to the glow relay through the
fuse (100A).
• Electric current from #55 Terminal of Fuse Box A
also enters ECM2 and #56 Terminal of ECM1,
then preheating circuit of the ECM1 and 2 is
started.
• Signals corresponding to the coolant temperature
and intake-air temperature are sent from the
coolant temperature sensor and intake-air
temperature sensor respectively to the ECM1
through the ECM2.
• Depending on the signals from the coolant
temperature sensor and intake-air temperature
sensor, the ECM1 earths #60 Terminal if the
temperatures are both below a set temperature,
and earths #60 Terminal, controlling excitement
time of the glow relay.
• While the glow relay is being excited, electricity
from the power source is supplied to the glow plug
from the glow relay, and so preheating is made.
• While preheating is being made, as #233 Terminal
of the ECM1 is earthed, electricity flows from
#233 Terminal of the monitor unit to #233 terminal
of the ECM1, and the monitor unit lights the glow
signal.
• In case preheating is not made, the glow signal is
lit for two seconds for checking of indicator lights.
NOTE: A signal value being supplied to the
intake-air heater from the glow relay is
entering #658 Terminal of the ECM1.
When the signal value becomes a set
temperature,
the
intake-air
heater
temperature is judged as having risen
above the set temperature.
In this case, even during preheating, the
ECM1 cancels earthing #60 Terminal and
excitement of the glow relay.
T2-4-6
SYSTEM/Electric System
Key Switch
Fuse Box A
264
362
692
157
From #6 Terminal
of Fuse Box B
55
163
693
108
54
12
99
698
699
700
697
79
Glow Relay
Monitor
Unit
Glow
Signal
CAN
Coolant
Temperature
Sensor
233
60
56
233
658
Intake-air
Heater
Fuse
(120A)
Battery
Relay
Fusible
Link
ECM1
ECM2
Intake-air
Temperature Sensor
To #638
Terminal of
Fuse Box B
Battery
T4HA-02-04-002
NOTE: Illustration shows flow of electricity in case
preheating is being made with the glow
relay excited and glow plug supplied with
electricity from the power source.
T2-4-7
SYSTEM/Electric System
STARTING
START)
CIRCUIT
(KEY
SWITCH:
Forward/Reverse Lever at Neutral Position
• At START of the key switch, Terminal B is
connected inside the key switch to Terminals M
and ST.
• Electric current from Terminal M excites the
battery relay through #54 and #55 Terminals of
Fuse Box A, so electricity from the battery power
source is led from the battery relay to Terminals B
of the starter motor.
• Electric current from Terminal M of the key switch
also flows to the neutral relay, and flows to all the
controllers as a signal for notifying the key switch
position at ON.
• Electric current from Terminal ST of the key switch
flows to #665 Terminal of the ECM1 and #115
Terminal of the ECM2 as a signal for notifying the
key switch position at START.
• At this moment, if both the forward and reverse
signals from the forward-reverse lever and the
forward-reverse switch do not come, the MC
cancels earthing of #627 Terminal, and the neutral
relay is not excited.
• Therefore, the ECM2 lets electric current flow to
Terminal S of the starter motor, and the starter
motor rotates because no signal flows from #116
Terminal of the ECM2 to the neutral relay.
T2-4-8
SYSTEM/Electric System
Key Switch
Fuse Box A
264
362
692
210
From #6 Terminal
of Fuse Box B
Signal of Key ON to (Monitor Unit)
Signal of Key ON to (MC, ECM, and ICX)
157
55
163
693
108
12
54
79
99
698
699
700
697
Neutral Relay
665
ECM1
Neutral Signal
(Forward/Reverse Lever)
Forward Signal
(Forward/Reverse Lever)
Reverse Signal (Forward/Reverse Lever)
Fuse
(120A)
115
116
Forward Signal (Forward/Reverse Switch)
Reverse Signal (Forward/Reverse Switch)
Fusible
Link
ECM2
627
82
83
MC
84
354
355
Battery Relay
Battery
To #638 Terminal
of Fuse Box B
Starter
Motor
Alternator
T4HA-02-04-004
T2-4-9
SYSTEM/Electric System
Forward/Reverse Lever at Operate Position
• Starting Safety Circuit (Neutral Relay)
• At START of the key switch, Terminal B can be
connected inside the key switch to Terminals M
and ST.
• Electric current from Terminal M excites the
battery relay through #54 and #55 Terminals of
Fuse Box A, so electricity from the battery power
source is led from the battery relay to Terminals B
of the starter motor.
• At this moment, if both the forward and reverse
signals from the forward-reverse lever and the
forward-reverse switch do not come, the MC
cancels earthing of #627 Terminal, and the neutral
relay is not excited.
• Therefore, the ECM2 lets electric current flow to
Terminal S of the starter motor, and the starter
motor rotates because no signal flows from #116
Terminal of the ECM2 to the neutral relay.
• At this moment, if the forward and reverse signals
from the forward-reverse lever or the
forward-reverse switch is come, the MC earthing
of #627 Terminal, and the neutral relay is excited.
• Therefore, ECM2 stop the electric current flow to
Terminal S of the starter motor, and the starter
motor does not rotates because signal flows from
#116 Terminal of the ECM2 to the neutral relay.
T2-4-10
SYSTEM/Electric System
Key Switch
Fuse Box A
264
362
692
210
From #6 Terminal
of Fuse Box B
Signal of Key ON to (Monitor Unit)
Signal of Key ON to (MC, ECM, and ICX)
157
54
55
163
693
108
12
79
99
698
699
700
697
Neutral Relay
665
ECM1
Neutral Signal
(Forward/Reverse Lever)
Forward Signal
(Forward/Reverse Lever)
Reverse Signal (Forward/Reverse Lever)
Fuse
(120A)
115
116
Forward Signal (Forward/Reverse Switch)
Reverse Signal (Forward/Reverse Switch)
Fusible
Link
ECM2
627
82
83
MC
84
354
355
Battery Relay
Battery
To #638 Terminal
of Fuse Box B
Starter
Motor
Alternator
T4HA-02-04-005
T2-4-11
SYSTEM/Electric System
CHARGING CIRCUIT (KEY SWITCH:ON)
• Engine starts, and the key switch returns to ON
automatically.
• At ON, Terminal B is connected inside the key
switch to ACC and Terminal M.
• Electric current from Terminal M of the key switch
excites the battery relay through #54 and #55
Terminals of Fuse Box A.
• When the engine rotates, the alternator begins to
generate electricity, and the electric current from
Terminal B of the alternator flows to the battery
through the battery relay, charging the battery.
• In the mean time, the electric current from
Terminal L of the alternator flows to #119 Terminal
of the monitor unit to have the monitor unit turn off
the alternator indicator, and also flows to #594
Terminal of the ICF and #592 Terminal of the GPS
to record history data of the engine operation
time.
T2-4-12
SYSTEM/Electric System
Key Switch
Fuse Box A
264
362
692
From #6 Terminal
of Fuse Box B
Alternator
Indicator
Monitor
Unit
592
GPS
119
594
ICX
To #638 Terminal
of Fuse Box B
157
867
55
163
693
108
12
144
133
121
696
695
698
699
700
54
79
99
120
674
697
Fuse
(120A)
Fusible
Link
Battery
Relay
Battery
ECM2
Starter
Motor
T4HA-02-04-006
Alternator
T2-4-13
SYSTEM/Electric System
SURGE VOLTAGE PREVENTION CIRCUIT
• When the engine is stopped (key switch: OFF),
the electric current from Terminal M of the key
switch is stopped, and the battery relay is turned
OFF.
• Even if the key switch is turned off, the engine
does not stop immediately keeping freewheeling,
and the alternator continues generation of
electricity.
• As the generated electric current does not flow to
the battery, surge voltage (voltage rise) is
generated, resulting in causes for failures of
electronic equipment like the controller and other
parts. For this reason, the surge voltage
protection circuit is provided.
• During charging, the electric generation current
from Terminal L of the alternator enters #119
Terminal of the monitor unit. Monitor unit earths
#33 Terminal to the ground.
• Electric current flows to the excitement circuit of
the load dump relay, and the load dump relay
works.
• Therefore, even if the key switch is turned OFF
during rotation of the engine, the electric current
from the battery keeps exciting the battery relay
through the load dump relay. Also, the battery
relay is turned OFF about ten seconds after the
alternator stops generation of electricity.
T2-4-14
SYSTEM/Electric System
Key Switch
Load Dump
Relay
Fuse Box B
838
348
149
577
327
222
323
6
11
9
35
158
127
654
2
7
39
42
37
381
711
33
Monitor
Unit
119
148
126
638
34
263
70
710
75
Fuse
(120A)
Fusible
Link
Battery
Relay
Battery
ECM2
Starter
Motor
Alternator
T4HA-02-04-007
T2-4-15
SYSTEM/Electric System
ENGINE STOP CIRCUIT
• When the key switch is turned OFF from ON, the
• ECM2 unexcites the fuel injection solenoid valve,
electric current flowing from Terminal M to ECM2
and #56 Terminal of the ECM1 to show the key
switch at ON is stopped.
and the engine is stopped.
Key Switch
Fuse Box A
264
362
692
210
From #6 Terminal
of Fuse Box B
157
54
55
163
80
108
12
79
99
698
699
700
697
To #638 Terminal
of Fuse Box B
56 ECM1
Fuel Injection
Solenoid Valve
Fuse
(120A)
CAN
Fusible
Link
Battery
Relay
ECM2
Battery
T4HA-02-04-001
T2-4-16
SYSTEM/Electric System
LAMPLIGHT CIRCUIT
• Head Light Circuit: for turning on and off head
lights, clearance lights and license light.
• Turn Signal Circuit: for turning on and off turn
signals
• Brake Light Circuit: for turning on and off brake
lights
• Hazard Light Circuit: for turning on and off hazard
light indicators
• Horn Circuit: for sounding horn
• Reverse Light/Buzzer Circuit: for turning on and
off reverse lights and reverse buzzer
• Parking Brake Circuit: for working and releasing
parking brake
• Emergency Steering Check Circuit (Optional): for
confirming operation of emergency steering pump
unit
T2-4-17
SYSTEM/Electric System
HEAD LIGHT CIRCUIT
Clearance and License Light Circuit
• Terminal B of the key switch is directly connected
to the head light switch.
• When the head light switch is positioned at
(Clearance Lights), part of the electricity from the
S terminal of the head light switch enters #47
Terminal of the monitor unit, and the illumination
light of the monitor unit is lit.
• Remainder of the electricity from the S terminal of
the head light switch enters #710 Terminal of
Fuse Box B, and further divided to #39 and #42
Terminals.
• Electricity from the power source coming out of
#39 Terminal of Fuse Box B lights front left and
rear left clearance lights.
• Electricity from the power source coming out of
#42 Terminal of Fuse Box B lights the license light
and the front right and rear right clearance lights.
T2-4-18
SYSTEM/Electric System
Head Light Switch
Key Switch
Fuse Box A
Illumination
Light
264
362
692
210
124
135
867
55
63
163
47
Monitor
Unit
157
123
54
121
696
695
698
699
700
Front Right
Clearance Light
120
694
697
Fuse Box B
838
348
149
577
Rear Right
Clearance Light
License
Light
126
6
11
9
35
158
127
654
2
7
39
42
37
381
711
638
34
263
70
710
75
Rear Left
Clearance Light
Fusible
Link
Front Left
Clearance Light
Battery
Battery Relay
T2-4-19
T4HA-02-04-009
SYSTEM/Electric System
Head Light Lighting Circuit
• When the key switch is turned ON, the electricity
from the power source coming out of Terminal M
of the key switch excites the battery relay through
#54 and #55 Terminals of Fuse Box A, and the
electricity from the battery power source flows to
Fuse Box A and Fuse Box B.
• Electricity from the battery power source coming
out of #124 Terminal of Fuse Box A enters the
right head light relay.
• Electricity from the battery power source coming
out of #121 Terminal of Fuse Box A enters the left
head light relay.
• Electricity from the battery power source coming
out of #127 Terminal of Fuse Box B enters the
high beam relay.
• When the head light switch is positioned at
(Head Lights), the electricity from the power
source coming out of Terminal S lights each of the
clearance lights (Refer to Clearance Light
Lighting Circuit.), and the electricity from the
power source coming out of Terminal H flows to
the high-low beam switch.
• At this moment, if the high-low beam switch is
turned to Lo (Low Beam), the electricity from the
power source enters the right head light relay and
the left head light relay, and the electricity from
the battery power source enters the head lights to
light them by exciting the respective relays.
• If the high-low beam switch is turned to Hi (High
Beam), the electricity from the power source
excites the high-beam relay, and the electricity
from the battery power source enters and lights
the high-beam lights. Electricity from the power
source coming out of the high-low beam switch
also enters #130 Terminal of the monitor unit, and
lights the high-beam indicators.
T2-4-20
SYSTEM/Electric System
Head Light Switch
High-Low Beam Switch
Key Switch
Lo
Hi
Fuse Box A
Monitor
Unit
High-Beam
Indicator
High-Beam Right Head Light Left Head Light
Relay
Relay
Relay
130
264
362
692
210
124
135
867
55
63
163
157
123
54
121
696
695
698
699
700
120
694
697
Fuse Box B
838
348
149
577
Right High-Beam Light
126
6
11
9
35
158
127
654
2
7
39
42
37
381
711
Right Head Light
Left High-Beam Light
Left Head Light
638
34
263
70
710
75
Fusible
Link
Battery
Battery Relay
T2-4-21
T4HA-02-04-010
SYSTEM/Electric System
TURN SIGNAL CIRCUIT
• Electricity from the battery power source also
• Electricity from the power source coming out of
flows to the flasher relay coming out of #11
Terminal of Fuse Box B.
• In case the turn signal switch is turned to left (L),
Terminal L of the turn signal switch is earthed, and
the left turn signal relay is excited.
the flasher relay enters the front and rear left turn
signal lights and #23 Terminal of the monitor unit
through the left turn signal relay.
• As a result, front and rear left turn signal lights
and the left turn signal indicators flicker.
Turn Signal Switch
Left
Turn Signal
Monitor
Unit
Right
Turn Signal
Key Switch
Left Turn
Signal Relay
Right Turn
Signal Relay
23
26
Rear Right
Turn Signal Light
Flasher
Relay
Fuse Box B
348
149
577
327
222
323
6
11
9
35
158
127
654
838
711
75
148
126
638
34
Front Right
Turn Signal
Rear Left
Turn Signal
Fusible
Link
Battery Relay
Front Left
Turn Signal
Battery
T4GB-02-03-011
T2-4-22
SYSTEM/Electric System
BRAKE LIGHT CIRCUIT
• When the key switch is turned ON, the electricity
• When the brake pedal is stepped, the brake light
from the power source coming out of Terminal M
of the key switch excites the battery relay, and the
electricity from the battery power source enters
#99 Terminal of Fuse Box A and the brake light
relay through #12 Terminal.
switch is earthed.
• As a result, the brake light relay is excited, and
the electricity from the battery power source
enters the brake lights, and light them.
Key Switch
From #6 Terminal
of Fuse Box B
Brake Light Relay
Brake Pedal
Fuse Box A
264
362
692
210
124
135
867
55
163
693
108
12
144
133
121
696
695
698
699
700
Brake Light Switch
Right Brake Light
157
123
54
79
99
120
694
697
Left Brake Light
Fusible
Link
Battery
Relay
Battery
To #638 Terminal
of Fuse Box B
T4GB-02-03-012
T2-4-23
SYSTEM/Electric System
HAZARD LIGHT CIRCUIT
• Electricity from the battery power source also
• Electricity from the power source coming out of
flows to the flasher relay coming out of #11
Terminal of Fuse Box B.
• In case the hazard switch is turned ON, the
hazard switch is earthed, and the left and right
turn signal relays are excited.
the flasher relay enters all of the front and rear left
and right turn signal lights and #23 and #26
Terminals of the monitor unit through the left and
right turn signal relays.
• As a result, all of the front and rear left and right
turn signal lights and the left and right turn signal
indicators flicker.
Turn Signal Switch
Left
Turn signal
Right
Turn signal
Monitor
Unit
Diode
A
Diode
C
Diode
B
Diode
D
Left Turn
Signal Relay
Right Turn
Signal Relay
23
26
Rear Right
Turn Signal Light
Front Right
Turn Signal Light
Hazard
Switch
Flasher
Relay
Key Switch
Fuse Box B
838
348
149
577
327
222
323
6
11
9
35
158
127
654
2
7
39
42
37
381
711
148
126
638
34
263
70
710
75
Rear Left
Turn Signal Light
Fusible
Link
Battery Relay
Front Left
Turn Signal Light
Battery
T4GB-02-03-013
T2-4-24
SYSTEM/Electric System
HORN CIRCUIT
• When the key switch is turned ON, the electricity
from the power source coming out of Terminal M
excites the battery relay through #54 and #55
Terminals of Fuse Box A, and the electricity from
the battery power source enters #120 Terminal of
Fuse Box A and the horn relay through #133
Terminal.
• Horn switch is earthed when pushed.
• As a result, the horn relay is excited, and the
electricity from the battery power source enters
the horn, and the horn sounds.
Key Switch
From #6 Terminal
of Fuse Box B
Fuse Box A
264
362
692
210
124
135
867
55
163
693
108
12
144
133
121
696
695
698
699
700
Horn Relay
Horn
Switch
Horn
157
123
54
79
99
120
694
697
Battery
Relay
Fusible
Link
Battery
To #638 Terminal
of Fuse Box B
T4GB-02-03-014
T2-4-25
SYSTEM/Electric System
REVERSE LIGHT/BUZZER CIRCUIT
• When the key switch is turned ON, the electricity
from the power source coming out of Terminal M
excites the battery relay through #54 and #55
Terminals of Fuse Box A.
• Electricity from the battery power source enters
#99 Terminal of Fuse Box A, and enters the
reverse light relay through #108 Terminal.
• When the forward-reverse lever is turned to
reverse, Terminal R is earthed, and the MC earths
#109 Terminal because the electricity from the
power source flows to the forward-reverse lever
through #84 Terminal of the MC.
• As a result, the reverse light relay is excited, and
the electricity from the battery power source flows
to the reverse light and the reverse buzzer.
T2-4-26
SYSTEM/Electric System
Forward/Reverse Lever
Key Switch
From #6 Terminal
of Fuse Box B
Fuse Box A
MC
84
264
362
692
210
124
135
867
55
163
693
108
12
144
133
121
696
695
698
699
700
Reverse
Light
Relay
109
Right Reverse Light
157
123
54
79
99
120
694
697
Reverse Buzzer
Left Reverse Light
Fusible
Link
Battery
Relay
Battery
To #638 Terminal
of Fuse Box B
T4GC-02-04-003
T2-4-27
SYSTEM/Electric System
PARKING BRAKE CIRCUIT
• When the key switch is turned ON, the electricity
• However, as a self-exciting circuit is formed in
from the power source coming out of Terminal M
excites the battery relay through #54 and #55
Terminals of Fuse Box A.
• Electricity from the power source enters #79
Terminal of Fuse Box A and Parking Brake Relay
1 through #163 Terminal of Fuse Box A.
• Electricity from the power source coming out of
Terminal D of Parking Brake Relay 1 through
Terminal B of Parking Brake Relay 1 flows to
Terminal B of Parking Brake Relay 2 and Terminal
B of the parking brake switch.
• Parking brake switch is composed of three circuits
of ON, NEUTRAL, and OFF, and so constructed
as to remain at ON when turned ON, but to
automatically return to NEUTRAL when turned
OFF.
• When the parking brake switch is turned OFF,
electric current flows from Terminal E of the
parking brake switch to Terminal A of Parking
Brake 2 and the parking brake solenoid valve.
• At this moment, if the engine is not running,
Parking Brake Relay 1 is excited because #684
Terminal of the monitor unit is earthed.
• Therefore, the parking brake cannot be released
because the electricity from the power source
having been supplied through Parking Brake 1 to
Terminal B of the parking brake switch and
Terminal B of the parking brake relay is blocked.
• In case the engine is running, Parking Brake
Relay 2 is excited because the electric current
from Terminal L of the alternator enters #119
Terminal of the monitor unit, releasing earthing of
#684 Terminal of the monitor unit.
• As a result, a circuit in which electricity flows from
Terminal C of Parking Brake Relay 2 to Terminal A
of Parking Brake Relay 2 (self-exciting circuit) is
formed, and the parking brake solenoid valve
works, releasing the parking brake.
• As the parking brake switch automatically returns
to neutral, the circuit from Terminal E of the
parking brake switch to Parking Brake Relay 2 is
blocked.
Parking Brake Relay 2, electric current keeps
flowing to the parking brake solenoid valve,
keeping the released condition of the parking
brake until the key switch is turned OFF or the
parking brake switch is turned ON.
IMPORTANT: Parking brake cannot be released
unless the engine is running.
T2-4-28
• When the parking brake switch is turned ON,
Terminal A of the parking brake switch is earthed,
and Parking Brake Relay 1 is excited.
• Electricity from the power source having been
supplied to Terminal B of Parking Brake Relay 2
and Terminal B of Parking Brake Switch through
Terminal D of Parking Brake Relay 2 is blocked.
• As a result, the parking brake works because
Parking Brake Relay 2 and the parking brake
solenoid valve are unexcited.
SYSTEM/Electric System
Key Switch
From #163Terminal
of Fuse Box A
From #6 terminal
of Fuse Box B
684
Monitor Unit
119
From Terminal L
of Alternator
(When forming a self-exciting circuit)
ON
NEUTRAL
Parking Brake
Switch
イ
Parking Brake Parking Brake
Relay 2
Relay 1
OFF
AB
E F GH
A B CD E
A B CD E
684
Monitor Unit
119
To #638 Terminal
of Fuse Box B
Fuse
(100A)
Battery
Relay
Fuse Box A
264
362
692
210
124
135
867
55
163
693
108
12
144
133
121
696
695
698
699
700
157
123
54
79
99
120
694
697
Battery
Parking Brake
Solenoid Valve
From Terminal L
of Alternator
T4GB-02-03-016
NOTE: Illustration shows flow of electric current
when the parking brake switch remains
pushed after the parking brake switch has
been turned OFF during rotation of the
engine.
T2-4-29
SYSTEM/Electric System
EMERGENCY STEERING CHECK CIRCUIT
(OPTIONAL)
(Manual Check Circuit)
• When the key switch is turned ON, the electric
current from Terminal M the battery relay, and the
electricity from the power source enters the
emergency steering relay through #323 terminal
of Fuse Box B, and also enters Terminal B of the
emergency steering pump unit.
• When the emergency steering check switch is
turned ON, electric current flows to #179 Terminal
of the monitor unit.
• At the same time, as the monitor unit excites #180
Terminal, the emergency steering relay is excited.
• Electricity from the power unit enters Terminal C
of the emergency steering pump unit through the
emergency steering relay, exciting Terminal B,
and the emergency steering pump unit is started.
IMPORTANT: Emergency steering pump unit is
not so designed as to be operated
for a long time. When its operation
has been confirmed, turn the
emergency steering check switch
OFF by stopping pushing the switch.
(Auto Check Circuit)(EU Model Only)
• When the engine is started by turning the key
switch to the ST position, the alternator starts
generating electricity.
• When part of the electricity generation signal from
Terminal L of the alternator enters the monitor unit,
and rises to the predetermined voltage, Terminal
#180 is earthed, and the emergency steering
relay is excited.
• Electricity from the power unit enters Terminal C
of the emergency steering pump unit through the
emergency steering relay, exciting Terminal B,
and the emergency steering pump unit is started.
• The emergency steering pump unit works for
several seconds, and then the earthed circuit of
Terminal #180 is automatically cancelled and the
emergency steering pump unit stops.
• In case hydraulic oil higher than the
predetermined value has been being delivered
during operation of the emergency steering pump
unit, the emergency steering pump delivery
pressure switch is turned OFF, and the automatic
inspection operation is stopped normally.
• In case hydraulic oil higher than the
predetermined value has not been being
delivered, the emergency steering pump delivery
pressure switch remains ON, and the emergency
steering operation warning lamp on the monitor
unit flickers to notify abnormality of the
emergency steering pump unit.
T2-4-30
SYSTEM/Electric System
Key Switch
Fuse Box A
264
362
692
210
124
135
464
55
163
80
108
12
157
123
54
79
120
Emergency
Steering
Check Switch
Emergency
Steering
Relay
694
695
698
699
700
697
Fuse Box B
Emergency
Steering
Pump Delivery
Pressure Sensor
(EU Model Only)
119
179
180
Emergency
Steering
Pump Unit
348
149
577
327
222
323
6
11
9
35
158
148
126
638
710
381
711
Monitor
Unit
838
75
Battery Relay
Fuse
(100A)
Battery
Alternator
T4GB-02-03-020
T2-4-31
SYSTEM/Electric System
(Blank)
T2-4-32
MEMO
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SECTION 3
COMPONENT OPERATION
Group 1 Pump Device
CONTENTS
Group 5 Steering Valve
Outline ...................................................... T3-1-1
Outline ...................................................... T3-5-1
Main Pump ............................................... T3-1-2
Operation .................................................. T3-5-4
Regulator.................................................. T3-1-4
Steering Overload Relief Valve ................. T3-5-8
Priority Valve .......................................... T3-1-18
Pilot Pump,Pump Delivery
Pressure Switch .................................. T3-1-19
Steering Main Relief Valve...................... T3-1-20
Group 2 Control Valve
Group 6 Pilot Valve
Outline (Two Lever Type Pilot Valve for
Front Attachment) ................................... T3-6-1
Operation .................................................. T3-6-2
Electromagnetic Detent............................. T3-6-6
Outline ...................................................... T3-2-1
Outline (Joystick Type Pilot Valve for
Hydraulic Circuit ....................................... T3-2-8
Front Attachment) ................................... T3-6-7
Main Relief Valve.................................... T3-2-12
Operation .................................................. T3-6-8
Overload Relief Valve ............................. T3-2-14
Electromagnetic Detent........................... T3-6-12
Restriction Valve..................................... T3-2-17
Outline (Lever Type Pilot Valve for
Negative Control Valve ........................... T3-2-18
Additional Circuit) (Optional) ................. T3-6-13
Flow Rate Control Valve ......................... T3-2-20
Operation ................................................ T3-6-14
Outline (Joystick Type Pilot Valve for
Group 3 Hydraulic Fan Motor
Outline ...................................................... T3-3-1
Operation ................................................. T3-3-4
Additional Circuit) (Optional) ................... T3-6-17
Operation ................................................ T3-6-18
Flow Control Valve.................................... T3-3-6
Reverse Control Valve .............................. T3-3-8
Fun Pump ............................................... T3-3-10
Group 4 Pilot Valve
Outline ...................................................... T3-4-1
Construction ............................................. T3-4-2
Operation ................................................. T3-4-3
4HAT-3-1
Group 7 Charging Block
Group 11 Brake Valve
Outline ...................................................... T3-7-1
Outline .................................................... T3-11-1
Priority Valve ............................................ T3-7-6
Operation ................................................ T3-11-4
Pilot Relief Valve ...................................... T3-7-7
Pump Torque Control Proportional
Group 12 Others
Solenoid Valve ....................................... T3-7-8
Pilot Shutoff Valve................................... T3-12-1
Service Brake Accumulator,
Propeller Shaft ........................................ T3-12-2
Pilot Accumulator ................................... T3-7-9
Emergency Steering Check Block ........... T3-12-3
Parking Brake Solenoid Valve................ T3-7-10
Emergency Steering Pump (Optional) ..... T3-12-4
Service Brake Pressure Sensor.............. T3-7-12
Parking Brake Pressure Sensor ............. T3-7-12
Group 8 Ride Control Valve
Outline ...................................................... T3-8-1
Operation ................................................. T3-8-4
Charge Cut Spool ..................................... T3-8-6
Over Load Relief Valve ............................. T3-8-8
Ride Control Accumlator ......................... T3-8-10
Drain Plug ...............................................T3-8-11
Group 9 Drive Unit
Outline ...................................................... T3-9-1
Torque Converter...................................... T3-9-2
Transmission ............................................ T3-9-4
Transmisson Regulator Valve ................. T3-9-26
Transmission Control Valve .................... T3-9-28
Manual Spool (Emergency Travel
Spool .................................................... T3-9-36
Proportional Solenoid Valve.................... T3-9-38
Group 10 Axle
Outline .................................................... T3-10-1
Differential .............................................. T3-10-2
Torque Proportioning Differential (TPD).. T3-10-6
Limited Slip Differential (LSD)................. T3-10-8
Service Brake ........................................T3-10-10
Final Drivel Axle Shaft ...........................T3-10-12
4HAT-3-2
COMPONENT OPERATION / Pump Device
OUTLINE
Pump device has a main pump (1) and a pilot pump (2),
and main pump (1) has a built-in priority valve (6).
Driving force of the engine is transmitted to the shaft
(3) through the transmission input shaft, and actuates
main pump (1) and pilot pump (2).
Main pump (1) is a swash-plate type variable
displacement axial plunger pump.
Pilot pump (2) is a gear pump.
Pump delivery pressure switch (4) is provided for
controlling the main pump.
1
2
5
6
3
4
T4GB-03-01-001
1 - Main Pump
3 - Shaft
5-
2 - Pilot Pump
4 - Pump Delivery Pressure
Switch
6-
T3-1-1
Steering Main Relief
Valve
Priority Valve
COMPONENT OPERATION / Pump Device
MAIN PUMP
Main pump supplies pressure oil for operating the
cylinders and other hydraulic components. Also, the
pump is provided with a regulator for controlling the
delivery flow.
Shaft (5) is connected with the cylinder block (1), and
shaft (5) and cylinder block (1) corotate.
1
2
When cylinder block (1) rotates, plungers (2)
reciprocate inside the cylinder block because of the
tilting of swash plate (4), and delivers the hydraulic oil.
Control of the main pump delivery is made by changing
the tilting angle of swash plate (4) with servo piston 1
(3) and servo piston 2 (6) which increase or decrease
the stroke of plungers (2).
3
4
5
6
8
7
T4GB-03-01-002
1 - Cylinder Block
2 - Plunger
34-
Servo Piston 1 (2 pieces)
Swash Plate
56-
T3-1-2
Shaft
Servo Piston 2
78-
Feed Back Lever
Link
COMPONENT OPERATION / Pump Device
Increase and Decrease Operations of Delivery
Flow
Tilting angle variation of swash plate (4) is made by
the movement of servo piston 1 (3) and servo piston
2 (6).
Movement of the servo pistons is controlled by the
regulator. Also, the feed back of the swash plate
movement is given to the regulator by feed back lever
(7) and link (8).
7
8
6
3
4
NOTE: Refer to the following pages for operation of
the regulator.
• Tilting Change Operation
Tilting center of the swash plate is located at A in the
drawings right.
Pilot pressure is always applied to servo piston 2 (6).
Therefore, when the circuit of servo piston 1’s (3) is
connected to the hydraulic oil tank, swash plate (4)
tilts clockwisw around A.
Conversely, as there are two servo piston 1’s (3),
when pilot pressure is applied to both of servo piston
1’s (3) and servo piston 2, the swash plate (4) tilts
counterclockwise around A.
T4GB-03-01-022
A
Minimum Tilting
6
3
4
• Feed Back Operation
End of feed back lever (7) is inserted into the boss
on the side face of the swash plate (4). When swash
plate (4) tilts, the boss also moves, and feed back
lever (7) moves together.
For example, if swash plate (4) tilts to the maximum
tilting position from the minimum tilting position, the
center of feed back lever (7) moves from B to C.
This movement of feed back lever (7) moves link (8),
and feed back is given to the regulator.
Housing
Maximum Tilting
8
7
T4GB-03-01-023
A
4
Boss
Housing
C
T3-1-3
B
T4GB-03-01-024
COMPONENT OPERATION / Pump Device
REGULATOR
Regulator controls flow of the main pump, receiving
various kinds of signal pressure.
The regulator includes the spring (1), sleeve 1 (2),
sleeve 2 (7), spool 1 (3), spool 2 (6), piston (4), load
piston (5), inner spring (8), and outer spring (9).
Regulator opens and closes the circuit leading to servo
piston 1 (10) by receiving various kinds of signal
pressure, and controls delivery flow of the pump by
varying the tilting angle of swash plate (11).
NOTE: Pilot primary pressure (Pg) is always
applied to Servo Piston 2 (12).
3
2
Pi1
T
Air
Vent
1
4
Pi2
Pg
ST
T
Pd1
T
5
7
6
10
8、9
Large
Small
Tilting Angle
12
T4GB-03-01-006
Pd1 - Pump Delivery Pressure
(Self Delivery Pressure)
ST - Pump Torque Control
Pressure
TReturn Line to Hydraulic
Oil Tank
T3-1-4
Pi1 - Pump Control
Pressure 1
Pi2 - Pump Control
Pressure 2
Pg - Pilot Primary
Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
2
5
4
3
6
7
10
4 - Piston
5 - Load Piston
6 - Spool 2
8
9
11
T4GB-03-01-007
12
1 - Spring
2 - Sleeve 1
3 - Spool 1
1
7 - Sleeve 2
8 - Inner Spring
9 - Outer Spring
T3-1-5
10 - Servo Piston 1(2 pieces)
11 - Swash Plate
12 - Servo Piston 2
COMPONENT OPERATION / Pump Device
Control Function of Regulator
Regulator has the following three control functions.
• Control by Pump Control Pressure
Pump flow control valve inside the control valve
controls the pump control pressure (Pi1 - Pi2) in
response to the operating stroke of the control lever.
By receiving this pump control pressure (Pi1 - Pi2),
the regulator increases or decreases the pump
delivery flow in response to the pressure.
When the control lever is operated, pump control
pressure (Pi1 - Pi2) lowers, and the regulator
increases the pump delivery flow. If the control lever
is returned to neutral, pump control pressure (Pi1 Pi2) rises, and the regulator decreases the pump
delivery flow.
Flow (Q)
0
Pump Control Pressure (Pi1-Pi2)
• Control by Pump Delivery Pressure (Self Delivery
Pressure)
Pump Delivery Pressure (Self Delivery Pressure)
Pd1 enters the regulator. In case this pump pressure
exceeds the set P - Q line, the pump delivery flow is
decreased to return the pressure to the P - Q line.
Flow (Q)
Pressure Increase
Flow Decrease
• Control by Pilot Pressure from Torque Control
Solenoid Valve
MC (Main Controller) makes arithmetic operations of
the operating conditions of the vehicle body, and
transmits signals to the pump torque control
solenoid valve to obtain needed pump torque.
Pump torque control solenoid valve transmits Pump
Torque Control Pressure ST corresponding to this
signal to the regulator. Regulator, receiving the pilot
pressure, decreases the pump delivery flow.
0
Flow (Q)
0
T3-1-6
Pressure (P)
Pressure (P)
COMPONENT OPERATION / Pump Device
(Blank)
T3-1-7
COMPONENT OPERATION / Pump Device
Control by Pump Control Pressure
Flow Decrease
1. When the control lever stroke is reduced,
pressure difference arising before and after the
flow control valve (difference between pressure
Pi1 and Pi2) in the control valve is enlarged.
2. Pump Control Pressure Pi1 pushes Spool 1 (3),
and Spool 1 (3) moves toward the arrow.
3. This movement causes Pilot Primary Pressure Pg
to be led to servo piston 1 (10) also.
4. As there are two servo piston 1’s (10), the swash
plate (11) tilts toward the flow decreasing
direction.
5. Movement of swash plate (11) is conveyed to
sleeve 1 (2) through feed back lever link (13).
Sleeve 1 (2) moves toward the movement of
spool 1 (3).
6. Pilot pressure having been led to servo piston 1
(10) is blocked when sleeve 1 (2) has moved the
same distance as spool 1 (3). This causes servo
piston 1’s (10) to stop and the flow decrease is
completed.
Flow (Q)
0
Pump Control Pressure (Pi1-Pi2)
3
2
Pi1
1
Air
Vent
T
4
Pi2
Pg
ST
T
Pd1
T
13
10
Small
Large
12
Tilting Angle
T4GB-03-01-006
1234-
Spring
Sleeve 1
Spool 1
Piston
Pd1 ST T-
T3-1-8
10 - Servo Piston 1
11 - Swash Plate
12 - Servo Piston 2
13 - Feed Back Lever Link
Pump Delivery Pressure
(Self Delivery Pressure)
Torque Control
Pressure
Return Line to Hydraulic
Oil Tank
Pi1 Pi2 Pg -
Pump Control
Pressure 1
Pump Control
Pressure 2
Pilot Primary Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
11
10
T4GB-03-01-008
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-009
T3-1-9
COMPONENT OPERATION / Pump Device
Flow Increase
1. When the control lever stroke is enlarged,
pressure difference arising before and after the
flow control valve (difference between pressure
Pi1 and Pi2) in the control valve is reduced.
2. Force due to spring (1) and Pump Control
Pressure Pi2 pushes spool 1 (3), and spool 1 (3)
moves toward the arrow.
3. This movement causes the circuit of servo piston
1’s (10) to be led to the hydraulic oil tank.
4. As Pilot Primary Presuure Pg is always applied to
servo piston 2 (12), the swash plate (11) tilts
toward the flow increasing direction.
5. Movement of the swash plate (11) is transmitted
to sleeve 1 (2) through the feed back lever link
(13). Sleeve 1 (2) moves toward the movement of
spool 1 (3).
6. When sleeve 1 (2) has moved the same distance
as spool 1 (3) did, communication of servo piston
1’s (10) with the hydraulic tank is stopped, and
this causes servo piston 1’s (10) to stop and the
flow increase is completed.
Flow (Q)
0
Pump Control Pressure (Pi1-Pi2)
3
2
Pi1
1
Air
Vent
T
4
Pi2
Pg
ST
T
Pd1
T
13
10
Large
Small
12
Tilting Angle
T4GB-03-01-006
1234-
Spring
Sleeve 1
Spool 1
Piston
10 - Servo Piston 1
11 - Swash Plate
12 - Servo Piston 2
13 - Feed Back Lever Link
Pd1 - Pump Delivery Pressure
(Self Delivery Pressure)
ST - Pump Torque Control
Pressure
TReturn Line to Hydraulic
Oil Tank
T3-1-10
Pi1 Pi2 Pg -
Pump Control
Pressure 1
Pump Control
Pressure 2
Pilot Primary Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
Pump
Control Pressure
Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-010
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-011
T3-1-11
COMPONENT OPERATION / Pump Device
Control by Pump Delivery Pressure
(Self Delivery Pressure)
Flow Decrease
1. When load is applied to the pump by making one
operation or another, Pump Delivery Pressure
Pd1 rises. (As done during an operation, the
pump control pressure (Pi1 - Pi2) remains
lowered.)
2. Load piston (5) pushes spool 2 (6), the inner
spring (8), and the outer spring (9), and Spool 2
(6) moves toward the arrow.
3. This movement causes Pilot Primary Pressure Pg
to be led to servo piston 1’s (10) also.
4. As there are two servo piston 1 (10), the swash
plate (11) tilts toward the flow decreasing
direction.
5. This movement of the swash plate (11) is
conveyed to sleeve 2 (7) through the feed back
lever link (13). Sleeve 2 (7) moves toward the
movement of spool 2 (6).
6. Pilot pressure having been led to servo piston 1
(10) is blocked when sleeve 2 (7) has moved the
same distance as spool 2 (6). This causes servo
piston 1’s (10) to stop and the flow decrease is
completed.
Flow (Q)
0
Pressure (P)
Pi1
T
Air
Vent
Pi2
Pg
ST
T
Pd1
T
5
7
6
10
8、9
Large
Small
Tilting Angle
12
13
T4GB-03-01-006
56789-
Load Piston
Spool 2
Sleeve 2
Inner Spring
Outer Spring
Pd1 - Pump Delivery Pressure
(Self Delivery Pressure)
ST - Pump Torque Control
Pressure
TReturn Line to Hydraulic
Oil Tank
T3-1-12
10 - Servo Piston 1
11 - Swash Plate
12 - Servo Piston 2
13 - Feed Back Lever Link
Pi1 Pi2 Pg -
Pump Control
Pressure 1
Pump Control
Pressure 2
Pilot Primary Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
Pump
Control Pressure
Pi1
5
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
9
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-012
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
13
Self Delivery
Pressure Pd1
9
12
10
11
T4GB-03-01-013
T3-1-13
COMPONENT OPERATION / Pump Device
Flow Increase
1. When the pump load is reduced, Self Delivery
Pressure Pd1 lowers. (As done during an
operation, the pump control pressure (Pi1 - Pi2)
remains lowered.)
2. Load piston (5) and spool 2 (6) are pushed by
inner spring (8) and outer spring (9), and spool 2
(6) moves toward the arrow.
3. This movement causes the circuit of servo piston
1’s (10) to be led to the hydraulic oil tank.
4. As Pilot Primary Presuure Pg is always applied to
servo piston 2 (12), swash plate (11) tilts toward
the flow increasing direction.
5. Movement of swash plate (11) is conveyed to
sleeve 2 (7) through feed back lever link (13).
sleeve 2 (7) moves toward the movement of spool
2 (6).
6. When sleeve 2 (7) has moved the same distance
as spool 2 (6), the openings of spool 2 (6) and
sleeve 2 (7) close, stopping communication of
servo piston 1’s (10) with the hydraulic tank, and
this causes servo piston 1’s (10) to stop and the
flow increase is completed.
Flow (Q)
0
Pressure (P)
Pi1
T
Air
Vent
Pi2
Pg
ST
T
Pd1
T
5
7
8、9
6
10
12
Large
Small
Tilting Angle
13
T4GB-03-01-006
56789-
Load Piston
Spool 2
Sleeve 2
Inner Spring
Outer Spring
Pd1 - Pump Delivery Pressure
(Self Delivery Pressure)
ST - Pump Torque Control
Pressure
TReturn Line to Hydraulic
Oil Tank
T3-1-14
10 - Servo Piston 1
11 - Swash Plate
12 - Servo Piston 2
13 - Feed Back Lever Link
Pi1 Pi2 Pg -
Pump Control
Pressure 1
Pump Control
Pressure 2
Pilot Primary Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
13
Self Delivery
Pressure Pd1
9
12
10
11
T4GB-03-01-014
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
Self Delivery
Pressure Pd1
13
12
10
11
T4GB-03-01-015
T3-1-15
COMPONENT OPERATION / Pump Device
Control of Torque Control Solenoid Valve by Pilot
Pressure
Flow Decrease
1. Command from the MC (main controller) drives
the pump torque control solenoid valve, and
Pump Torque Control Pressure ST enters the
regulator.
2. Adding to Self Delivery Pressure Pd1, Pump
Torque Control Pressure ST works on load piston
(5).
3. Load piston (5) pushes spool 2 (6), inner spring
(8), and outer spring (9), and spool 2 (6) moves
toward the arrow.
4. This movement causes Pilot Primary Pressure Pg
to be led to servo piston 1’s (10) also.
5. As there are two servo piston 1 (10), swash plate
(11) tilts toward the flow decreasing direction.
6. This movement of swash plate (11) is conveyed to
sleeve 2 (7) through feed back lever link (13).
sleeve 2 (7) moves toward the movement of spool
2 (6).
7. Pilot pressure having been led to servo piston 1
(10) is blocked when sleeve 2 (7) has moved the
same distance as spool 2 (6). This causes servo
piston 1’s (10) to stop and the flow decrease is
completed.
Flow (Q)
0
Pressure (P)
Pi1
T
Air
Vent
Pi2
Pg
ST
T
Pd1
T
5
7
8、9
6
10
Large
Small
Tilting Angle
12
13
T4GB-03-01-006
56789-
Load Piston
Spool 2
Sleeve 2
Inner Spring
Outer Spring
Pd1 - Pump Delivery Pressure
(Self Delivery Pressure)
ST - Pump Torque Control
Pressure
TReturn Line to Hydraulic
Oil Tank
T3-1-16
10 - Servo Piston 1
11 - Swash Plate
12 - Servo Piston 2
13 - Feed Back Lever Link
Pi1 Pi2 Pg -
Pump Control
Pressure 1
Pump Control
Pressure 2
Pilot Primary Pressure
(From Pilot Pump)
COMPONENT OPERATION / Pump Device
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
9
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-016
5
Pump
Control Pressure
Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
13
Self Delivery
Pressure Pd1
9
12
10
11
T4GB-03-01-017
T3-1-17
COMPONENT OPERATION / Pump Device
PRIORITY VALVE
(Refer to the Main Curcuit in the SYSTEM /
Hydraulic System)
Main pump has a built-in priority valve.
Priority valve is installed for effectively distributing the
main pump delivery oil to the steering valve and the
control valve.
Before Steering Operation
Operation
1. Before Steering Operation
Pressure oil from the main pump tends to flow to
the steering valve through Port CF, but flows to
the both ends of the priority valve spool because
Port CF is blocked.
Pressure oil on one end of the spool flows from
Port LS to the hydraulic oil tank through the
steering valve, and its pressure is lowered. The
spool to both ends of which different pressures
are applied moves toward Port LS, overcoming
the the spring force. Therefore, the majority of the
main pump pressure oil flows to the control valve
through Port EF.
2. In Steering Operation
If steering is operated, and the steering valve
spool moves, pressure at Port LS rise in response
to the amount of the steering valve spool
movement. The spool is pushed up by the
pressure at Port LS and the spring force.
Therefore, the main pump pressure oil flows to
both Port EF and Port CF. When the steering
valve spool moves to the maximum stroke, the
majority of the main pump pressure oil flows to
the steering valve through Port CF.
Port
CF
To Steering Valve
From Main Pump
To Control Valve
Port
EF
Spool
Spring
Port LS
To Hydraulic
Oil Tank
T4GB-03-01-018
In Steering Operation
Port
CF
To Steering Valve
From Main Pump
To Control Valve
Spool
Port
EF
Spring
Port LS
T4GB-03-01-019
T3-1-18
COMPONENT OPERATION / Pump Device
PILOT PUMP
Drive gear (1) is driven throught the shaft of the main
pump, and the diven gear (2) geared to this also
rotates.
1 - Drive Gear
Suction Port
1
2
2 - Driven Gear
Delivery Port
T137-02-03-005
PUMP DELIVERY PRESSURE SWITCH
Pump delivery pressure necessary for various kinds of
control is sensed. Hydraulic pressure is received by
the diaphragm (9), and deformation of the diaphragm
is sensed as an electric signal.
6 - Earth
7 - Output
8 - Electric Source (5V)
9 - Pressure-applied Part
(Diaphragm)
6
T3-1-19
7
8
9
T157-02-03-010
COMPONENT OPERATION / Pump Device
STEERING MAIN RELIEF VALVE
Main pump has a built-in steering main relief valve.
When the steering circuit pressure exceed the set
pressure, pressure oil is returned to the hydarulic oil
tank through inside of the main pump housing.
Before Operation
Steering Circuit Pressure for
up to Set Pressure
Operation
In case steering circuit pressure exceed the set
pressure, the puppet is pushed toward the spring,
and pressure is returned to the hydraulic oil tank
through inside of the main pump housing.
NOTE: When the steering relief valve is operated,
the spool of the priority valve moves to the
Port LS end, and the majority of the
pressure oil from the main pump flows to
the control valve through Port EF. (Refer to
T3-1-18.)
T4GB-03-01-020
In Operation
Steering Circuit Pressure for
less than Set Pressure
To Main Pump
Housing
T4GB-03-01-021
T3-1-20
COMPONENT OPERATION / Control Valve
OUTLINE
Control valve controls pressure, flow, and direction of
oil in the hydraulic circuit.
The control valve includes the main relief valve,
overload relief valve, negative control valve, restriction
valve, flow control valve, and spool, and the operation
is of the hydrauil pilot type.
Lift Arm
Bucket
T4GB-03-02-002
T3-2-1
COMPONENT OPERATION/Control Valve
Component Layout
1
2
3
4
5
6
8
7
8
9
11
10
T4GB-03-02-008
T3-2-2
COMPONENT OPERATION/Control Valve
D
10
C
7
8
6
8
A
E
5
4
3
T4GB-03-02-009
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4 - Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7 - Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9 - Low-pressure Relief Valve
T3-2-3
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
COMPONENT OPERATION/Control Valve
1
2
3
4
5
6
8
7
8
9
11
10
T4GB-03-02-008
T3-2-4
COMPONENT OPERATION/Control Valve
Section A*
11
7
6
8
8
Section B*
1
2
5
4
T4GB-03-02-010
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4-
Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7-
Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9-
* Refer to T3-2-3
T3-2-5
Low-pressure Relief Valve
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
COMPONENT OPERATION/Control Valve
1
2
3
4
5
6
8
7
8
9
10
11
T4GB-03-02-008
T3-2-6
COMPONENT OPERATION/Control Valve
Section C*
10
9
Section D*
C
3
E
Section E*
3
T4GB-03-02-011
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4-
Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7-
Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9-
* Refer to T3-2-3.
T3-2-7
Low-pressure Relief Valve
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
COMPONENT OPERATION/Control Valve
HYDRAULIC CIRCUIT
Main Circuit
Main circuit contains a parallel circuit, which enables
compound operations.
Main circuit (between the pump and the cylinder) is
provided with the main relief valve. The main relief
valve prevents pressure inside the main circuit from
increasing over the set pressure during operation
(when any control lever is operated).
Front circuit (between the control valve and the
cylinder) of the lift arm bucket is provided with the
overload relief valve. Overload relief valve prevents
surge pressure from being developed be external
loads in the front circuit and from increasing over the
set pressure at neutral position of the spool (neutral
position of the control lever).
T3-2-8
COMPONENT OPERATION/Control Valve
Bucket Cylinder
Lift Arm
Cylinder
Control Valve
Overload
Valve
Bucket
Lift Arm
Parallel Circuit
Main Relief Valve
Main Pump
T4GB-03-02-023
T3-2-9
COMPONENT OPERATION/Control Valve
Pilot Operation Circuit
Pressure oil from the pilot valve (shown in numerals)
works on the spool of the control valve, and moves
the spool.
• Pressure oil is being sent to the bucket spool for
dumping and crowding operations.
• Pressure oil is being sent to the lift arm spool for
raising and lowering operations.
Spool for lowering is two-staged, and the first
stage is for lowering the lift arm, while the second
stage is for floating the lift arm.
T3-2-10
COMPONENT OPERATION/Control Valve
Bucket
Pilot Valve
Lift Arm
Pilot Valve
1
3
2
4
Pilot Pump
Control Valve
Bucket
2
1
4
Lift Arm
3
4
Main Pump
T4GB-03-02-024
1 - Bucket Crowding
2 - Bucket Dumping
3 - Lift Arm Lowering
4 - Lift Arm Raising
T3-2-11
COMPONENT OPERATION/Control Valve
MAIN RELIEF VALVE
Main relief valve prevents pressure inside the main
circuit from increasing over the set pressure during
operation of the cylinder.
This prevents oil leakage from the hoses and piping
fittings as well as cylinder breakage.
Operation of Relief Valve
1. Pressure at port HP (in the main circuit) works on
the pilot poppet through orifice A of the main
poppet and orifice B of the seat.
2. When the pressure at port HP rises to the setting
force of spring B, the pilot poppet opens, and
pressure oil flows to port LP (in the hydraulic oil
tank) passing through passage A and the
periphery of the sleeve.
3. At this time, pressure difference arises between
port HP and the spring chamber, caused by orifice
A.
4. When this pressure difference reaches the value
corresponding to the set force of spring A, the
main poppet opens, and the pressure oil at port
HP flows to port LP.
5. As a result, pressure in the main circuit lowers.
6. If the main circuit pressure lowers to the set
pressure, the main poppet is closed by the force
of spring A.
T3-2-12
COMPONENT OPERATION/Control Valve
Normally (When not Relieving):
Orifice A
Main Poppet
Orifice B
Seat
Passage A Spring B
HP
Sleeve
LP
Spring
Chamber
Spring A
Pilot Poppet
T4GB-03-02-025
When Relieving:
Orifice A
Main Poppet Orifice B Seat
Passage A
Spring B
HP
Sleeve
LP
Spring
Chamber
Spring A
Pilot Poppet
T4GB-03-02-026
T3-2-13
COMPONENT OPERATION/Control Valve
OVERLOAD RELIEF VALVE
(With Make-up Function)
Overload relief valve is installed on the bottom end of
the lift arm, and the bottom and rod ends of the bucket.
Overload relief valve so controls pressure in each front
circuit not to rise abnormally.
It also makes make-up operation by refilling oil from
the hydraulic tank for preventing cavitation.
Operation
1. Pressure at port HP (in the front circuit) works on
the pilot poppet through the orifice of the piston.
2. When the pressure at port HP rises to the setting
force of spring B, the pilot poppet opens, and
pressure oil flows to port LP (in the hydraulic oil
tank) passing through passage A and the
periphery of the sleeve.
3. At this time, pressure difference arises between
port HP and the spring chamber, caused by the
orifice.
4. When this pressure difference reaches the value
corresponding to the set force of spring A, the
piston and the main poppet open, and the
pressure oil at port HP flows to port LP.
5. As a result, pressure in the the main circuit lowers.
6. If the front circuit pressure lowers to the set
pressure, the piston and the main poppet are
closed by the force of spring A.
Make-up Operation
1. When the pressure at port HP (in the front circuit)
lowers than the pressure at port LP (in the
hydraulic oil tank), the sleeve moves right.
2. Hydraulic oil at port LP flows into port HP, and
cavitation is prevented.
3. When the pressure at port HP rises to the set
pressure, the sleeve is closed by the force of
spring C.
T3-2-14
COMPONENT OPERATION/Control Valve
Normally (When not Relieving):
Main Poppet
Sleeve
Spring A
Passage A
Spring B
HP
LP
Orifice
Piston
When Relieving:
T4GB-03-02-030
Spring Chamber
Main Poppet
Pilot Poppet
Sleeve
Spring A
Spring C
Passage A
Spring B
HP
LP
Orifice
Piston
T4GB-03-02-031
Spring
Chamber
When Making Up:
Pilot Poppet
Sleeve
HP
LP
T4GB-03-02-032
Spring C
T3-2-15
COMPONENT OPERATION/Control Valve
(Blank)
T3-2-16
COMPONENT OPERATION/Control Valve
RESTRICTION VALVE
Restriction valve is installed at the inlet part to the pilot
circuit on both ends of the spool for the lift arm.
If the pilot valve is made at the neutral position during
operation of the lift arm, the pilot pressure oil having
been supplied to the spool for the lift arm is drained
through the orifice of the check valve of the restriction
valve, and pilot pressure gradually lowers.
As a result, shock to the body occurring in operation of
the front attachment can be reduced by gradually
returning the lift arm spool to the neutral position.
Check Valve
Spool End
Orifice
Pilot
Valve End
T4GB-03-02-014
T3-2-17
COMPONENT OPERATION/Control Valve
NEGATIVE CONTROL VALVE
Orifice
Control valve has a built-in negative control valve.
Negative control valve controls the main pump delivery
flow of the main pump by the flow control pressure
(Pc1 and Pc2).
Negative
Control Valve
Pc2
Pc1
Operation
• At Neutral
Pressure oil coming through the control valve
neutral circuit at neutral position of the control
valve is supplied as pilot pressure for controlling
the pump delivery flow from before and after the
orifice of the negative control valve installed at the
outlet of the control valve.
At this time, spool B moves left because
differential pressure is occurring between the Pc1
and higher than Pc2. Therefore, pilot pressure
(PS2) enters the large-diameter chamber for the
servo piston through spool B and spool A. Pilot
pressure (PS2) also enters the small-diameter
chamber for the servo piston, but as the the
large-diameter chamber has a larger area than
the small-diameter chamber, the servo piston
moves right, and the pump delivery flow is
reduced.
• In Operation
In operations handling the lift arm and bucket,
pressure oil is not supplied to Pc1 and Pc2.
At this time, differential pressure is lowered
between the Pc1 and Pc2, so the regulator for the
main pump is at neutral, and restriction of delivery
flow is not made (increase pump delivery flow).
Main Pump
Neutral
Circuit
T3-2-18
Servo Piston
Large-Diameter
Chamber
Small-Diameter
Chamber
Spool A
Pilot Pressure
(PS2)
Spool B
T4GB-03-02-033
COMPONENT OPERATION/Control Valve
From Main Pump
*
,*
Section D １ ２
Pc1
E
Orifice Part
*
Section E １
Pc1
Pc2
Negative Control
Valve
T4GB-03-02-017
*1: Refer to T3-2-3.
*2: Refer to T3-2-7.
T3-2-19
COMPONENT OPERATION/Control Valve
FLOW CONTROL VALVE
In Compound Operation of Bucket Crowding and
Lift Arm Raising
Flow control valve is installed in the bucket circuit, and
narrows the circuit in compound operations, giving
priority to operations of the other actuators.
In Single Operation of Bucket Crowding
1. Pressure oil from the main pump flows toward the
poppet.
2. Pressure oil entering the poppet pushes the
poppet left, and flows to the bucket spool, with its
small portion also flowing to the bucket spool
through the check valve inside the poppet to be
supplied to the bucket cylinder.
1. Part of the pressure oil from the main pump is
supplied to the lift arm cylinder through the lift arm
spool.
2. Remainder of the pressure oil from the main
pump is supplied toward the bucket spool.
3. Pressure oil from the main pump passes the
parallel circuit, and flows to the changeover valve
through the check valve of the poppet.
4. At this time, the changeover valve is positioned
on the orifice end because pilot pressure for
raising the lift arm is working on the changeover
valve.
5. By the effect of the orifice of the changeover valve,
pressure on the spring end of the poppet rises,
and force to push the poppet right (for closing)
arises.
6. As a result, flow to the bucket spool is restricted,
and more pressure oil is supplied to the lift arm
end having higher pressure, and both the bucket
cylinder and the arm cylinder move.
Spring A
Check Valve
Spring B
Poppet
to Bucket Spool
Pilot Pressure
for Lift Arm Raising
Pressure Oil
from Main Pump
Changeover Valve
To Hydraulic Oil Tank
To Bucket Spool
T1V1-03-03-064
T3-2-20
COMPONENT OPERATION/Control Valve
In Single Operation of Bucket Crowding
Bucket
Cylinder
Spring A
Bucket Spool
Poppet
Pilot Pressure
Spring B
Lift Arm Spool
Check
Valve
Main Pump
T4GB-03-02-021
In Compound Operation of Bucket Crowding and Lift Arm Raising
Bucket
Cylinder
Spring A
Poppet
Bucket Spool
Pilot Pressure
Pilot Pressure
Changeover
Valve
Check
Valve
Parallel Circuit
Lift Arm Cylinder
Spring B
Lift Arm
Spool
Pilot Pressure
Main Pump
T4GB-03-02-022
T3-2-21
COMPONENT OPERATION/Control Valve
(Blank)
T3-2-22
COMPONENT OPERATION / Hydraulic Fan Motor
OUTLINE
Shaft of the fan motor is provided with the cooling fan,
and the pressure oil from the fan pump rotates the
cooling fan by driving the shaft.
Fan motor has a built-in reverse control solenoid valve,
a flow adjustment solenoid valve, and others, and
controls the motor rotational direction and rotation
speed.
Reverse Control
Solenoid Valve
Flow Adjustment
Solenoid Valve
C
A
B
B
C
A
T4GB-03-03-001
T3-3-1
COMPONENT OPERATION / Hydraulic Fan Motor
Component Layout
Cooling Fan
Shaft
Fan Motor
Reverse Spool
Reverse Control
Solenoid Valve
Flow Control Valve
Reverse Signal
from MC
Flow Control Valve
Spring
Flow Adjustment
Solenoid Valve
Relief Valve
Hydraulic Oil
Tank
Hydraulic Oil
Tank
Fan Pump
Flow Adjustment
Command Signal
from MC
T3-3-2
T4GB-02-02-008
COMPONENT OPERATION / Hydraulic Fan Motor
Section B-B*
Section C-C*
5
6
7
8
9
10
Section A-A*
1
2
3
4
12
11
T4GB-03-03-002
1 - Shaft
4 - Cylinder Block
2 - Thrust Plate
3 - Piston
5 - Center Spring
6 - Valve Pｌａｔｅ
7 - Flow Adjustment Solenoid
Valve
8 - Flow Control Valve
9 - Relief Valve
*Refer to T3-3-1
T3-3-3
10 - Reverse Control Solenoid
Valve
11 - Reverse Spool
12 - Flow Control Valve Spring
COMPONENT OPERATION / Hydraulic Fan Motor
OPERATION
Fan motor is a swash-plate type axial piston motor,
and converts the pressure oil sent from the fan motor
into rotational motion.
Operation Principle of Hydraulic Motor
1. Pressure oil from the fan motor is led to cylinder
block (4) through valve plate (6).
2. Pressure oil entering cylinder block (4) pushes
respective pistons (3).
3. This force F1 works on thrust plate (2), and is
divided into the component forces of F2 and F3
because thrust plate (2) is fixed to shaft (1) at an
angle of ⍺°.
4. Resultant force of F3 is a rotational force, and
rotates cylinder block (4) through pistons (3).
5. Cylinder block (4) is conncted to shaft (1) by the
splines, and the output shaft rotates.
T3-3-4
COMPONENT OPERATION / Hydraulic Fan Motor
α°
F1
F3
F2
2
1
4
2
3
4
6
3
T4GB-03-03-003
From Fan Pump
To Tank
T4GB-03-03-004
T3-3-5
COMPONENT OPERATION / Hydraulic Fan Motor
FLOW CONTROL VALVE
In case the cooling water and oil are below the set
temperature, the flow control valve supplies necessary
amount of the pressure oil from the fan pump, and
returns redundant amount to the tank to make control
for lowering the engine load and wind noise of the
cooling fan.
Operation
1. Pressure oil flowing from port P works on the A
end as upstream pressure of flow control valve
orifice (8), and on the B end as its downstream
pressure, and the differential pressure works on
flow control valve spring (12).
2. When the pressure difference becomes larger
than the set force, flow control valve spool (8)
moves, and redundant flow flows to port T.
T3-3-6
COMPONENT OPERATION / Hydraulic Fan Motor
7
8
From Fan Pump
P
B
A
12
T
T4GB-03-03-005
To Tank
T3-3-7
COMPONENT OPERATION / Hydraulic Fan Motor
REVERSE CONTROL VALVE
Fan motor is reversed by operations of the reverse
control solenoid valve and the reverse spool.
Operation
• At Neutral of Reverse Control Solenoid Valve
1. When reverse control solenoid valve (1) is at
neutral, the pressure oil (P) from the fan pump is
blocked by changeover valve (2).
2. As reverse spool (11) is being pushed by spring
(4), the pressure oil (P) from the fan pump flows
to port MB, and the fan motor rotates normally.
• In Operation of Reverse Control Solenoid Valve
1. When reverse control solenoid valve (1) is
operated, the pressure oil from the fan pump
flows to the right end of reverse spool (11)
through changeover valve (2).
2. When the pressure oil entering the right end of
reverse spool (11) overcomes the spring (4),
reverse spool (11) moves leftwards.
3. Pressure oil (P) from the fan pump flows to port
MA, and the fan motor makes reverse rotation.
T3-3-8
COMPONENT OPERATION / Hydraulic Fan Motor
At Neutral
1
P
OFF
2
MB
MA
4
T
3
T4GB-03-03-006
In Operation
1
P
ON
2
MA
MB
4
T
T3-3-9
3
T4GB-03-03-007
COMPONENT OPERATION / Hydraulic Fan Motor
FAN PUMP
Fan pump is a gear pump always supplying pressure
oil to the fan motor during the engine operation.
Fan pump is installed to the engine.
1
2
3
4
5
T4GB-03-03-008
6
1 - Drive Gear
2 - Oil Seal
3 - Bushing
4 - Body
5 - Cover
6 - Front Cover
7
8
9
7 - Gasket
8 - Driven Gear
9 - Side Plate
T3-3-10
10
10 - Gasket
COMPONENT OPERATION / Steering Pilot Valve
OUTLINE
Steering pilot valve is located between the brake/pilot
pump and the steering valve.
Steering pilot valve supplies the pressure oil from the
pilot pump to the steering valve in response to the
movement of the steering handle. (Refer to the
Steering Curcuit in the SYSTEM / Hydraulic System)
Port L (for Steering Left)
Port R (for Steering Right)
Steering
Handle
T487-03-02-001
Port T
(to Hydraulic Oil Tank)
Port P
(from Brake/Pilot Pump)
T3-4-1
COMPONENT OPERATION / Steering Pilot Valve
CONSTRUCTION
8
7
11
Steering pilot valve consists of gerotor (8), drive (7),
sleeve (3), spool (4), pin (5), housing (1), centering
springs (2), and others.
10
When the steering handle is rotated, spool (4) rotates,
and an oil passage is generated between spool (4) and
sleeve (3). Flow of the pressure oil from the pilot pump
is controlled by spool (4) and sleeve (3), and flows to
the steering valve.
Centering springs (2) are arranged both in spool (4)
and sleeve (3), and so function as to return sleeve (3)
to the neutral position when holding the handle is
stopped.
9
1
2
5
4
3
4
2
1
6
T1F3-03-07-002
3
Port R
Port L
Hole
5
Port P
10
9
8
7
6
T4GB-03-04-008
1 - Housing
2 - Centering Spring
3 - Sleeve
456-
Spool
Pin
Plate
789-
T3-4-2
Drive
Gerotor
Spacer
10 - Cap
11 - Check Valve
COMPONENT OPERATION / Steering Pilot Valve
OPERATION
4
Sleeve (3), spool (4), and drive (7) are mutually
connected by pin (5). When the handle (or the spool
(4)) is turned, a relative angular difference arises
between sleeve (3) and spool (4) because the hole of
spool (4) is a lengthened one.
Movement of the steering handle is conveyed only to
spool (4), and port P (from the steering pump) is
connected to port R (to the steering valve) or port L
through sleeve (3) and spool (4).
1
3
Port L
2
Port R
Handle
Port T
Port P
7
8
7
T4GB-03-04-007
11
1
6
10
9
2
T1F3-03-07-002
1
5
4
3
T3-4-3
7
8
COMPONENT OPERATION / Steering Pilot Valve
Steering Left:
4. Return oil from the steering valve enters port R,
and flows in the order of housing (1) - sleeve (3) spool (4) - sleeve (3) - port T to return to the
hydraulic oil tank.
5. When the pressure oil from the brake/pilot pump
enters gerotor (8), gerotor (8) rotates leftwards.
Rotation of gerotor (8) is transmitted to the sleeve
(3) through drive (7), and sleeve (3) rotates
leftwards similarly.
6. When sleeve (3) rotates the same amount of turns
as spool (4), passages of sleeve (3) and spool (4)
are closed, and operation of the steering valve is
stopped.
7. Therefore, gerotor (8) rotates in response to
rotation of the handle, and the steering valve is
operated in response to the amount of turns of the
handle.
1. When the steering handle is turned left, spool (4)
rotates, and the pressure oil from the brake/pilot
pump flows in the order of port P - sleeve (3) spool (4) - sleeve (3) - housing (1) - gerotor (8).
2. Pressure oil from gerotor (8) flows in the order of
housing (1) - sleeve (3) - spool (4) - sleeve (3) port L - steering valve, and controls the steering
valve.
3. Steering valve drives the steering cylinder with the
pressure oil from the main pump, and directs the
vehicle body toward left.
Steering Cylinder
Steering Valve
Main Pump
Port L
Port R
Port P
Port T
Brake/Pilot
Pump
1
8
7
4
2
3
Steering Pilot Valve
T4GB-03-04-009
T3-4-4
L
R
P
COMPONENT OPERATION / Steering TPilot
Valve
Steering Right
When the steering handle is turned right, the
pressure oil from the pilot pump flows in the order of
port P - port R - steering cylinder, and operates the
steering valve to direct the front wheel right.
Return oil from the steering valve flows in the order of
port L - port T to return to the hydraulic oil tank.
T4GB-03-04--010
Neutral
When the steering handle is not being turned, the oil
from the pilot pump works on port P of the steering
pilot valve, but does not flow to the steering valve
because it is blocked by spool (4). Therefore, the
steering cylinder is not operated.
T
P
4
T4GB-03-04--011
T3-4-5
COMPONENT OPERATION / Steering Pilot Valve
(Blank)
T3-4-6
COMPONENT OPERATION / Steering Valve
OUTLINE
Steering valve is located between the main pump and
the steering cylinder.
Steering valve supplies the pressure oil from the main
pump to the steering cylinder in response to the pilot oil
pressure of the steering pilot valve.
Steering cylinder is provided with the overload relief
valve.
A
C
B
T4GB-03-04-001
T3-5-1
COMPONENT OPERATION / Steering Valve
Component Layout
4
1
2
3
Port A
Port T
Port B
Port Pa
Port Pb
5
Port A: Pressure for Steering
Right
Port P: From Main Pump
6
Port DR
Port P
Port LS
Port B: Pressure for Steering
Left
Port T: Return to Hydraulic Oil
Tank
4
5
Port Pa: Pilot Pressure for
Steering Right
Port LS: To Port LS of Priority
Valve
T3-5-2
T4GB-03-04-002
Port Pb: Pilot Pressure for
Steering Left
Port DR: Return to Hydraulic Oil
Tank
COMPONENT OPERATION / Steering Valve
Section A
*
7
Port P
Port DR
1
Port T
Section B
*
3
Port LS
Port B
Port A
2
Port Pb
Port Pa
4
5
7
Section C
*
T4GB-03-04-003
4
6
T4GB-03-04-006
1 - Spool
2 - Overload Relief Valve
3 - Overload Relief Valve
4 - Lord Check Valve
5 - Variable Orifice
6 - Fixed Orifice
*: Refer to T3-5-1
T3-5-3
7-
Passage A
COMPONENT OPERATION / Steering Valve
OPERATION
In Neutral
1. When steering spool (1) is in the neutral position,
port A and port B of the steering cylinder are
closed.
2. Pressure oil from the main pump does not flow to
the steering cylinder because port P is closed.
T3-5-4
COMPONENT OPERATION / Steering Valve
Section A
*
Port P
Port DR
Port T
Section B
:*
Port B
Port A
T4GB-03-04-004
1
*: Refer to T3-5-1.
T3-5-5
COMPONENT OPERATION / Steering Valve
When Steering Left
1. When the steering handle is turned left, the pilot
pressure oil is sent to port Pb from the steering
pilot valve, and spool (1) moves right.
2. Pressure oil from the main pump is sent to the
steering valve through port P, and further sent to
passage A (7) through variable orifice (5).
3. Pressure oil in passage A (7) pushes and opens
load check valve (4), and flows to the steering
cylinder through port B.
4. And the return oil from the steering cylinder enters
spool (1) through port A, and returns to the
hydraulic oil tank through port T.
5. Also, the pilot pressure oil flowing into port Pb
pushes spool (1) on port Pb end, while flowing to
port Pa after being decompressed by fixed orifice
(6). This reduces the shock caused by fast
operation of the handle. (Refer to T3-5-2 and also
Steering Curcuit in the SYSTEM / Hydraulic
System)
NOTE: Opening area of the variable orifice (5) is
proportional to the amount of stroke of the
spool (1) due to the pilot pressure from the
steering pilot valve. (Refer to the Steering
Curcuit in the SYSTEM / Hydraulic System)
T3-5-6
COMPONENT OPERATION / Steering Valve
Port P
1
7
5
Port T
Port LS
Port B
Port A
Port Pb
Port Pa
4
6
5
7
T3-5-7
T4GB-03-04-005
COMPONENT OPERATION / Steering Valve
STEERING OVERLOAD RELIEF VALVE
Steering overload relief valve is installed in the left and
right steering circuits. Overload relief valve controls
pressure in the respective steering circuits from rising
abnormally high when the steering cylinder is moved
by an external force.
Make-up Operation
Operation of Relief Valve
1. Pressure at port HP (in the steering circuit) works
on the pilot poppet, passing the orifice in the
piston.
2. When the pressure at port HP rises to the setting
force of spring B, the pilot poppet opens, and
pressure oil flows to port LP (in the hydraulic oil
tank), passing passage A and the periphery of the
sleeve.
3. At this moment, pressure difference arises
between port HP and the spring chamber caused
by the orifice.
4. When this pressure difference reaches the value
corresponding to the set force of spring A, the
piston and the main poppet open, and the
pressure oil at port HP flows to port LP.
5. As a result, the pressure in the steering cylinder
circuit lowers.
6. If the steering cylinder circuit pressure lowers to
the set pressure value, the piston and the main
poppet are closed by the force of spring A.
T3-5-8
1. When the pressure at port HP (in the steering
cylinder circuit) lowers than the pressure at port
LP (in the hydraulic oil tank), the sleeve moves
right.
2. Hydraulic oil flows into port HP, and cavitation is
prevented.
3. If the pressure at port HP rises to the set pressure
value, the sleeve is closed by the force of spring
C.
COMPONENT OPERATION / Steering Valve
Normally (When not Relieving):
Main
Poppet
Sleeve
Spring A
Passage A
Spring B
HP
T4GB-03-02-030
LP
Orifice
Piston
When Relieving:
Spring Chamber
Main
Poppet
Pilot
Poppet
Sleeve
Spring A
Spring C
Passage A
Spring B
HP
LP
Orifice
Piston
T4GB-03-02-031
Spring
Chamber
In Make-up Operation:
Pilot
Poppet
Sleeve
HP
LP
T4GB-03-02-032
Spring C
T3-5-9
COMPONENT OPERATION / Steering Valve
(Blank)
T3-5-10
COMPONENT OPERATION / Pilot Valve
OUTLINE (TWO LEVER TYPE PILOT
VALVE FOR FRONT ATTACHMENT)
Pilot valve is a valve for controlling the pilot pressure
oil for moving the spool of the control valve. Provided
with the PPC (Pressure Proportional Control Valve)
function,
the
pilot
valve
outputs
pressure
corresponding to the control lever stroke of the control
lever, and moves the spool of the control valve.
The bi-directional, four-port type is adopted for the
front-end attachment.
Port No.
1
2
3
4
Bucket Crowd
Bucket Tilting Out
Lift Arm Lower
Lift Arm Raise
Hydraulic Symbol
P
1
2
3
4 T
T4GB-03-05-001
P
T3-6-1
1
2
3
4
T
T4GB-03-05-002
COMPONENT OPERATION / Pilot Valve
OPERATION
At Neutral (between A and B of Pusher Stroke)
1. At the neutral position of the control lever, spool
(7) is completely blocking the pressure oil of port
P. Also, the outlet port is connected to port T
through the notch part of spool (7), and the
pressure oil at the output port is equal to the
pressure in the hydraulic tank.
2. When the control lever is moved slightly, lever (1)
is tilted, and push rod (2) and pusher (3) are
pushed in. Pusher (3) and spring guide (4) remain
mutually connected, and move downward,
compressing return spring (6).
3. At this time, spool (7) is pushed by balance spring
(5), and moves downward until the clearance in
Part A becomes zero.
4. During this movement, the output port remains
connected with port T, and pressure oil is not
supplied to the output port.
NOTE: Lever stroke during the period when the
clearance (A) becomes zero is the play of
the control lever.
T3-6-2
E
Pilot
Pressure
F
D
C
A
B
Pusher Stroke
Output Diagram
T505-02-07-006
COMPONENT OPERATION / Pilot Valve
Pusher Stroke: between A and B
1
2
3
4
5
6
Port T
(Clearance of
Part A: 0)
（A）
Port P
Notch Part
7
Output Port
1 - Lever
2 - Push Rod
3 - Pusher
4 - Spring Guide
T4GB-03-05-004
T4GB-03-05-003
5 - Balance Spring
6 - Return Spring
T3-6-3
7-
Spool
COMPONENT OPERATION / Pilot Valve
During Metering or Pressure Decrease (In Pusher
Stroke between C and D)
Full Stroke (Pusher Stroke between E and F)
1. When the control lever is further tilted, the ouput
port is connected with port P through spool (7).
2. Pressure oil from Port P flows into the output port
through spool (7), and the pressure at the output
port is raised.
3. Pressure at the output port works on face B of
spool (7), and tends to push up spool (7).
4. In case the force tending to push up the spool (7)
is smaller than the spring force of balance spring
(5), balance spring (5) is not compressed.
Therefore, port P and the output port remain
connected, and the pressure at the output port
keeps rising.
5. When the pressure at the output port rises further,
the force tending to push spool (7) up increases. If
this force becomes larger than the force of
balance spring (5), spool (7) moves upwards,
compressing the balance spring (5).
6. When spool (7) moves upward, the output port is
not connected any longer, and pressure oil stops
flowing from port P to the output port.
And pressure increase at the output port is
stopped.
7. In this way, balance spring (5) is compressed by
the amount spool (7) is pushed down, and the
pressure at the output port is the balanced
pressure working on the spring force and spool
(7).
T3-6-4
1. When the control lever is fully stroked, pusher (3)
moves downward until spring guide (4) contacts
the shoulder part of the casing.
2. At this time, spool (7) is directly pushed by the
bottom of pusher (3). Therefore, the output port
remains connected with port P through the notch
part of spool (7) because even if the pressure at
the output port is raised, spool (7) does not move
upward.
3. As a result, the pressure on the output port end is
equal to the pressure at port P.
Stroke amount C of the pusher determines the
total stroke of the lever.
E
Pilot
Pressure
F
D
C
A
B
Pusher Stroke
Output Diagram
T505-02-07-006
COMPONENT OPERATION / Pilot Valve
Pusher Stroke: between C and D
Pusher Stroke: between E and F
3
5
(C)
Port T
4
Notch Part
Face B
Port P
Port P
7
7
Output Port
3-
Pusher
4-
Spring Guide
Output Port
T4GB-03-05-005
5-
T3-6-5
Balance Spring
7-
Spool
T4GB-03-05-006
COMPONENT OPERATION / Pilot Valve
Electromagnetic Detent
Coil for detent is installed at the push rod part of the
pilot valve.
3. Adsorbed condition is retained until the coil
assembly is unexcited or until adsorption is
forcefully cancelled by moving the control lever
the other way around.
1. When one of the control levers is tilted, push rod
(2) and plate (8) of the other are pushed upwards
by the spring force.
2. If the control lever is operated until its stroke end,
plate (8) of the other is adsorbed by coil assembly
(10).
2
10
8
T4GB-03-05-007
2-
Push Rod
8-
Pｌａｔｅ
10 - Coil Assembly
T3-6-6
COMPONENT OPERATION / Pilot Valve
OUTLINE (JOYSTICK TYPE PILOT VALVE
FOR FRONT ATTACHMENT)
Port No.
1
2
3
4
Bucket Crowd
Bucket Tilting Out
Lift Arm Lower
Lift Arm Raise
Hydraulic Symbol
1
2
3
4
P
T
T4GB-03-05-001
2
3
T
1
4
P
T3-6-7
T4GB-03-05-008
COMPONENT OPERATION / Pilot Valve
OPERATION
At Neutral
1. At neutral, spool (7) completely blocks the
pressure oil at port P. Also, the output port is
connected with port T through the fine control
hole of spool (7).
For this reason, the pressure at the output port is
equal to the pressure at port T.
2. If the control lever is tilted slightly, disc (1) is tilted,
and push rod (2) and piston (3) are pushed in.
Piston (3) pushes down spring guide (4) and
balance spring (5), and moves downward.
3. At this time, spool (7) is pushed by spring (5), and
moves downward until the clearance at part A
becomes zero.
4. During this movement, the output port remains
connected with port T, and pressure oil is not
supplied to the output port.
NOTE: Lever stroke during the period when the
clearance (A) becomes zero is the play of
the control lever.
T3-6-8
COMPONENT OPERATION / Pilot Valve
At Neutral
1
2
3
4
5
6
Port T
(A)
Port P
(Clearance of Part A: 0)
Fine Control Hole
7
Output Port
T4GB-03-05-009
12-
Disc
Push Rod
3 - Piston
4 - Spring Guide
T4GB-03-05-010
56-
T3-6-9
Balance Spring
Return Spring
7 - Spool
COMPONENT OPERATION / Pilot Valve
During Metering or Pressure Decrease
Full Stroke
1. When the control lever is further tilted, the ouput
port is connected with port P through the fine
control hole of spool (7).
2. Pressure oil from port P flows into the output port
through spool (7), and the pressure at the output
port is raised.
3. Pressure at the output port works on spool (7),
and tends to push up spool (7).
4. In case the force tending to push up spool (7) is
smaller than the spring force of balance spring (5),
balance spring (5) is not compressed. Therefore,
port P and the output port remain connected, and
the pressure at the output port keeps rising.
5. When the pressure at the output port rises further,
the force tending to push spool (7) up increases. If
this force becomes larger than the force of
balance spring (5), spool (7) moves upwards,
compressing the balance spring (5).
6. When spool (7) moves upward, the output port is
not connected any longer, and pressure oil stops
flowing from port P to the output port.
And pressure increase at the output port is
stopped.
7. In this way, balance spring (5) is compressed by
the amount spool (7) is pushed down, and the
pressure at the output port is the balanced
pressure working on the spring force and spool
(7).
1. When the control lever is fully stroked, disc (7)
pushes down push rod (2) and piston (3), and
spring guide (4) pushes down spool (7).
2. Output port is connected with port P through the
fine control hole of spool (7).
3. Spool (7) is being pushed down by spring guide
(4), and the output port remains connected
through the fine control hole of spool (7) because
even if the pressure at the output port is raised,
spool (7) does not move upward.
4. As a result, the pressure on the output port end is
equal to the pressure at Port P.
T3-6-10
COMPONENT OPERATION / Pilot Valve
During Metering or Pressure Decrease
Full Stroke
2
3
4
5
Fine Control Hole
Port P
Fine Control Hole
Port P
7
7
Output Port
Output Port
T4GB-03-05-011
23-
Push Rod
Piston
45-
Spring Guide
Balance Spring
T4GB-03-05-012
7-
T3-6-11
Spool
COMPONENT OPERATION / Pilot Valve
ELECTROMAGNETIC DETENT
Coil for detent is installed at the push rod part of the
pilot valve.
3. Adsorption condition is retained until coil
assembly (8) is unexcited or until adsorption is
forcefully cancelled by operating the control lever
toward the other direction.
1. When one of the control levers is tilted, push rod
(2) and plate (9) of the other are pushed upwards
by the spring force.
2. If the control lever is operated until its stroke end,
plate (9) of the other is adsorbed by coil assembly
(8).
2
8
9
T4GB-03-05-013
2-
Push Rod
8-
Coil Assembly
9-
T3-6-12
Plate
COMPONENT OPERATION / Pilot Valve
OUTLINE (LEVER TYPE PILOT VALVE
FOR ADDITIONAL CIRCUIT) (OPTIONAL)
Port No.
1
2
Optional
Optional
T
T
Hydraulic Symbol
P
P
T
P
1
1
2
2
T554-02-07-009
1
T3-6-13
2
T1LA-03-04-001
COMPONENT OPERATION / Pilot Valve
OPERATION
At Neutral (between A and B of Pusher Stroke)
1. At the neutral position of the control lever, spool
(7) is completely blocking the pressure oil of port
P. Also, the outlet port is connected to port T
through the notch part of spool (7), and the
pressure oil at the output port is equal to the
pressure in the hydraulic tank.
2. When the control lever is moved slightly, cam (1)
is tilted, and pusher (2) and spring guide (4) are
pushed in. Pusher (3) and spring guide (4) move
downward, remaining mutually connected, and
compressing return spring (6).
3. At this time, spool (7) is pushed by balance spring
(5), and moves downward until the clearance in
Part A becomes zero.
4. During this movement, the output port remains
connected with port T, and pressure oil is not
supplied to the output port.
5. When the pressure at the output port rises further,
the force tending to push spool (7) up increases. If
this force becomes larger than the force of
balance spring (5), spool (7) moves upwards,
compressing balance spring (5).
6. When spool (7) moves upward, the notch part
closes, and pressure oil stops flowing from port P
to the output port. And pressure increase at the
output port is stopped.
7. In this way, balance spring (5) is compressed by
the amount the spool (7) is pushed down, and the
pressure at the output port is the balanced
pressure working on the spring force and spool
(7).
NOTE: Lever stroke during the period when Part A
becomes zero is the play of the control
lever.
Pilot
Pressure
D
During Metering or Pressure Decrease (In Pusher
Stroke between C and D)
1. When the control lever is further tilted, the hole
part of spool (7) is connected with notch part (B).
2. Pressure oil from port P flows into the output port
through notch part (B) and the hole part of spool
(7), and the pressure at the output port is raised.
3. Pressure at the output port works on the bottom of
spool (7), and tends to push up spool (7).
4. In case the force tending to push up spool (7) is
smaller than the spring force of balance spring (5),
balance spring (5) is not compressed. Therefore,
port P and the output port remain connected, and
the pressure at the output port keeps rising.
T3-6-14
C
A
B
Pusher Stroke
T1F3-03-09-004
Output Diagram
COMPONENT OPERATION / Pilot Valve
Between A and B of Pusher Stroke
1
2
3
4
5
Port T
6
(A)
Clearance at
Part A: 0
Port P
Hole Part
7
Passage
T1LA-03-04-002
Output Port
T1LA-03-04-003
Between C and D of Pusher Stroke
5
Port T
Notch Part (B)
Port P
Hole Part
7
Output Port
1 - Cam
2 - Pusher
3 - Plate
4 - Spring Guide
T1LA-03-04-004
56-
T3-6-15
Balance Spring
Return Spring
7 - Spool
COMPONENT OPERATION / Pilot Valve
(Blank)
T3-6-16
COMPONENT OPERATION / Pilot Valve
OUTLINE (JOYSTICK TYPE PILOT VALVE
FOR ADDITIONAL CIRCUIT) (OPTIONAL)
Port No.
1
2
3
4
Optional
Optional
Optional
Optional
P
Hydraulic
Symbol
T
P
1
3
2
4
4
T105-02-07-020
3
１
2
T1V1-03-04-001
T
T3-6-17
COMPONENT OPERATION / Pilot Valve
OPERATION
Head of spool (6) is hung by the top face of spring
guide (3). Spring guide (3) is lifted up by return spring
(5).
At Neutral (Output Diagram: between A and B):
1. At neutral, spool (6) completely blocks the
pressure oil at port P (from the pilot pump). Also,
the output port is connected with port T (to the
hydraulic oil tank) through the internal passage of
spool (6).
2. For this reason, the pressure at the output port (to
the control valve) is equal to the pressure at Port
T.
3. If the control lever is tilted slightly, cam (1) is tilted,
and pusher (2) is pushed in. Pusher (2) and
spring guide (3), mutually connected, push down
return spring (5), and moves downward.
4. At this time, the pressures at the output port and
port T are equal, so spool (6) moves downward
with the bottom face of its head keeping contact
with spring guide (3) by the force of balance
spring (4).
5. This condition continues until hole part (7) of
spool (6) is connected with port P.
T3-6-18
E
Pilot
Pressure
F
D
C
A B
Lever Stroke
T523-02-05-001
Output Diagram
COMPONENT OPERATION / Pilot Valve
1
1
2
2
3
3
4
4
5
5
6
7
Port P
6
6
Output Port
Port T
7
1 - Cam
2 - Pusher
Port T
7
Port P
Output Port
3 - Spring Guide
4 - Balance Spring
Port T
Port P
Output Port
T1V1-03-04-007
5 - Return Spring
6 - Spool
T3-6-19
T1V1-03-04-008
7 - Hole Part
COMPONENT OPERATION/Pilot Valve
During Metering or Pressure Decrease (Output
Diagram: between C and D)
1. When the control lever is further tilted and pusher
(2) is pushed down, hole part (7) of spool (6)
reaches port P, and the prsessure oil from port P
flows into the output port.
2. Pressure at the output port works on the bottom of
spool (6), and tends to push up spool (6).
3. In case the force working on spool (6) is smaller
than the spring force of balance spring (4),
balance spring (5) is not compressed. Therefore,
spool (6) is not pushed up, and the pressure at
the output port keeps rising.
4. When the pressure at the output port rises further,
the force tending to push spool (6) up increases. If
this force becomes larger than the force of the
balance spring (4), spool (6) moves upwards,
compressing the balance spring (4).
5. When spool (6) moves upward, hole part (7)
closes, pressure oil stops flowing from Port P to
the output port, and pressure increase at the
output port is stopped.
6. In this way, the balance spring (4) is compressed
by the amount spool (6) is pushed down, and the
pressure at the output port is the balanced
pressure working on the spring force and spool
(6).
T3-6-20
E
Pilot
Pressure
F
D
C
A B
Lever Stroke
T523-02-05-001
Output Diagram
COMPONENT OPERATION/Pilot Valve
1
1
2
2
3
3
4
4
5
5
6
6
Port T
7
Port P
7
Output Port
1 - Cam
2 - Pusher
Port T
3 - Spring Guide
4 - Balance Spring
Port P
Output Port
T1V1-03-04-009
5 - Return Spring
6 - Spool
T3-6-21
7 - Hole Part
T1V1-03-04-010
COMPONENT OPERATION/Pilot Valve
Full Stroke (Output Diagram: between E and F)
1. When the control lever is fully stroked, pusher (2)
moves downward until it contacts the shoulder
part of the casing.
2. At this time, spool (6) is directly pushed by the
bottom of the pusher (2). Therefore, even if the
pressure at the output port is raised, hole part (7)
of spool (6) is not closed.
3. As a result, the pressure on the output port end is
equal to the pressure at port P.
E
Pilot
Pressure
D
C
A
NOTE: Stroke amount E of the pusher (2)
determines the total stroke of the lever.
B
Lever Stroke
T523-02-05-001
Output Diagram
T3-6-22
F
COMPONENT OPERATION/Pilot Valve
1
2
2
3
4
5
E
6
Port T
7
Port P
Output Port
1 - Cam
2 - Pusher
3 - Spring Guide
4 - Balance Spring
T1V1-03-04-011
T1V1-03-04-007
5 - Return Spring
6 - Spool
T3-6-23
7 - Hole Part
COMPONENT OPERATION/Pilot Valve
(Blank)
T3-6-24
COMPONENT OPERATION / Charging Block
OUTLINE
Charging block is installed for supplying the pressure
oil from the pilot pump not only to the service brake
accumulator and the brake valve by giving them priority,
but also to the parking brake, the steering pilot valve,
and others.
Charging block consists of the priority valve, relief
valve, pump torque control proportional solenoid valve,
pilot relief valve, check valve, and others.
2
Port for Attaching
Service Brake
Accumulator (Rear)
Port for Attaching
Service Brake
Accumulator (Front)
3
5
Pump Torque
Control
Proportional
Solenoid Valve
13
Parking Brake
Solenoid Valve
17
Port for Attaching
Pilot Accumulator
T4GB-03-06-001
T3-7-1
COMPONENT OPERATION / Charging Block
Component Layout
1
2
3
4
5
6
7
8
22
9
10
11
21
12
13
14
20
15
16
17
18
T4GB-03-06-013
4
19
1 - Service Brake Accumulator
(Rear)
2 - Adaptor
9 - Priority Valve
16 - Port BR3 （To Parking Brake）
10 - Pilot Relief Valve
3 - Port M2
(To Rear End of Brake Valve)
4 - Check Valve
5 - Port M1
(To Front End of Brake Valve)
6 - Service Brake Accumulator
(Front)
7 - Service Brake Pressure Sensor
8 - Port P (from Pilot Pump)
11 - Port DR (To Hydraulic Oil Tank)
17 - Port PS2
(To Main Pump Regulator
and Ride Control Valve (Optional))
18 - Pilot Accumulator
12 - Port DR2(To Hydraulic Oil Tank)
13 - Port PS1
(To Steering Pilot Valve)
14 - Port X
（To Main Pump Regulator）
15 - Parking Brake Pressure Sensor
T3-7-2
19 - Port PP （To Pilot Shutoff Valve）
20 - Parking Brake Solenoid Valve
21 - Pump Torque Control Proportional
Solenoid Valve
22 - Relief Valve
COMPONENT OPERATION / Charging Block
11
Section V-V*
10
14
Section U-U*
12
21
15
16
Section T-T*
20
Section S-S
19
*
18
4
T4GB-03-06-003
*Refer to T3-7-1.
4
T3-7-3
COMPONENT OPERATION / Charging Block
Layout Drawing
1
2
3
4
5
6
7
8
22
9
10
11
21
12
13
14
20
15
16
17
18
T4GB-03-06-013
4
19
1 - Service Brake Accumulator
(Rear)
2 - Adaptor
9-
Priority Valve
3 - Port M2
(To Rear End of Brake Valve)
4 - Check Valve
5 - Port M1
(To Front End of Brake Valve)
6 - Service Brake Accumulator
(Front)
7 - Service Brake Pressure Sensor
8 - Port P (From Pilot Pump)
11 - Port DR (To Hydraulic Oil Tank)
10 - Pilot Relief Valve
12 - Port DR2 (To Hydraulic Oil Tank)
13 - Port PS1
(To Steering Pilot Valve)
14 - Port X
（To Main Pump Regulator）
15 - Parking Brake Pressure Sensor
T3-7-4
16 - Port BR3 （To Parking Brake）
17 - Port PS2
(To Main Pump Regulator
and Ride Control Valve (Optional))
18 - Pilot Accumulator
19 - Port PP （To Pilot Shutoff Valve）
20 - Parking Brake Solenoid Valve
21 - Pump Torque Control Proportional
Solenoid Valve
22 - Relief Valve
COMPONENT OPERATION / Charging Block
Section Z-Z*
6
1
4
Section Y-Y*
*
Section X-X
7
8
4
Section W-W*
22
9
*Refer to T3-7-1.
T3-7-5
T4GB-03-06-004
COMPONENT OPERATION / Charging Block
PRIORITY VALVE (REFER TO THE PILOT
CURCUIT IN THE SYSTEM / HYDRAULIC
SYSTEM)
1. Pressure oil from the pilot pump flows in through
port P, and works on the both ends of the plunger
of the priority valve.
2. Same pressure is applied to the both ends of the
plunger, so the plunger does not move, and a
restricted amount of pressure oil is supplied to the
other pilot circuits.
3. When the service brake accumulator is
accumulated exceeding the set pressure, the
piston of the relief valve pushes the needle valve.
4. Pressure oil in the spring chamber of the plunger
flows to the hydraulic oil tank through port DR.
5. Plunger is pushed toward the spring chamber to
stroke because the spring chamber is
decompressed.
6. A larger amount of the pressure oil from the pilot
pump is supplied to the other pilot circuits through
the priority valve.
Below Set Pressure of Service Brake Accumulator
Relief Valve
From Port P
Plunger
(Section W-W)
T4GB-03-06-005
To Service Brake Circuit
To Other
Pilot Circuits
Above Set Pressure of Service Brake Accumulator
Needle Valve
Piston
Service Brake
Accumulator
Pressure
To Port Dr
From Port P
Plunger
Spring Chamber
(Section W-W)
T4GB-03-06-006
To Other Pilot Circuits
T3-7-6
COMPONENT OPERATION / Charging Block
PILOT RELIEF VALVE
1. Pilot relief valve prevents the pressure in the pilot
circuit from increasing over the set pressure
during operations of the actuators like the pilot
valve.
2. When the pilot circuit pressure is above the set
pressure, pressure oil works on the poppet of the
pilot relief valve.
3. Poppet works toward the spring to be connected
with port DR.
4. Pressure oil in the pilot circuit returns to the
hydraulic oil tank through port DR.
5. When the pilot circuit pressure is below the set
pressure to the spring force, the poppet moves
left, closing connection of port DR.
Normally
Poppet
(Section V-V)
From Port P
T4GB-03-06-007
When Relieving
Poppet
(Section V-V)
T3-7-7
Port DR
Spring
T4GB-03-06-008
COMPONENT OPERATION / Charging Block
PUMP TORQUE CONTROL PROPORTIONAL SOLENOID VALVE (REFER TO THE
PILOT CURCUIT IN THE SYSTEM /
HYDRAULIC SYSTEM)
Pilot pressure supplied to the main pump regulator for
controlling the pump delivery flow is controlled by the
operation of the pump torque control proportional
solenoid valve.
Not in Operation of Solenoid Valve
To Main Pump
Regulator
Port X
1. When there is no signal from the MC (Main
Controller), the spool of the solenoid valve is
being pushed by the spring.
2. Pilot pressure oil is supplied to port ST of the main
pump regulator through port X.
3. When signal is transmitted from the MC, the spool
moves toward the spring in response to the signal
of the spool, and the amount of the pilot pressure
oil flowing out of port X is lowered.
4. When the signal from the MC becomes the
maximum value, the spool fully strokes toward the
spring, and the pilot pressure oil is blocked by the
spool.
5. Port X and port DR2 are connected, and the pilot
pressure oil at port X is lost.
Spring
(Section U-U)
Pilot Pressure Oil
T4GB-03-06-009
In Operation of Solenoid Valve
Port X
Port
DR2
Spool
(Section U-U)
Spring
Pilot Pressure Oil
T4GB-03-06-010
T3-7-8
COMPONENT OPERATION / Charging Block
SERVICE BRAKE ACCUMULATOR /
PILOT ACCUMULATOR
Accumulator is installed in the pilot circuit leading to
the service brake and the pilot valve.
High-pressure nitrogen gas is contained in the
accumulator, and the pilot pressure oil compresses
the nitrogen gas through the diaphragm.
Circuit pressure oil is retained by compression of the
nitrogen gas.
IMPORTANT: Construction of the accumulator
does not allow disassembly.
Replace the whole assembly, when
necessary.
Seal Ring
Retainer
Shell
Diaphragm
Valve Poppet
T4GB-03-06-011
T3-7-9
COMPONENT OPERATION / Charging Block
PARKING BRAKE SOLENOID VALVE
Pressure oil from the pilot pump is accumulated in the
pilot accumulator, and its pressure always works on
the outlet of the parking brake solenoid valve.
When the parking brake solenoid valve is operated,
the pilot accumulator enters the parking brake through
the spool, and releases the parking brake.
Parking Brake
Solenoid Valve
Port for Attaching
Pilot Accumulator
T3-7-10
T4GB-03-07-004
COMPONENT OPERATION / Charging Block
Not in Operation
Parking Brake
Pressure Sensor
Parking Brake
Drain Port
Spool
Spring
Parking Brake
Solenoid Valve
(Section T-T)
Pilot Accumulator
Pressure
T4GB-03-07-005
In Operation
Parking Brake
Pressure Sensor
Parking Brake
Spool
Spring
Parking Brake
Solenoid Valve
(Section T-T)
Pilot Pressure
Accumulator
Pressure
T3-7-11
T4GB-03-07-006
COMPONENT OPERATION / Charging Block
SERVICE BRAKE PRESSURE SENSOR
Brake pressure necessary for the service brake is
sensed. Sensor is installed in the service brake circuit
of the charging block, and senses the oil pressure of
the service brake accumulator.
1 - Earth
2 - Output
3 - Electric Power Source
（5V）
4 - Pressure Applied Part
（Diaphragm）
1
2
4
3
T4GB-03-06-012
PARKING BRAKE PRESSURE SENSOR
Brake pressure oil necessary for the parking brake is
sensed. Sensor is installed in the parking brake circuit
of the charging block, and senses the oil pressure of
the pilot accumulator.
3 - Pressure-applied Part
5 - (Diaphragm)
6 - Earth
7-
Output
8-
Electric Source （5V）
5
6
7
8
T176-03-01-023
T3-7-12
COMPONENT OPERATION / Ride Control Valve
OUTLINE
(Refer to the SYSTEM / Control System)
Ride control valve enables stable traveling by
absorbing the force generated in the lift arm cylinder in
traveling on rough roads.
Ride control valve consists of the ride control solenoid
valve, spool, charge-cut spool, overload relief valve,
and others.
Overload
Relief Valve
A
B
Ride Control
Solenoid Valve
T4GB-03-08-001
T3-8-1
COMPONENT OPERATION / Ride Control Valve
Component Layout
Lift Arm
Cylinder
Ride Control
Accumulator
5
Ride Control Valve
SP
3
Pi
1
4
B
A
2
To Hydraulic Oil Tank
T
From Charging
Block
T4GB-03-08-002
1 - Ride Control Solenoid Valve
2 - Charge-cut Spool
34-
Overload Relief Valve
Spool
5-
T3-8-2
Draing Plug
COMPONENT OPERATION / Ride Control Valve
Section A*
Port Pi
To Ride Control
Accumulator
1
Port SP
3
Port B
Port A
Port T
2
*Refer to T3-8-1.
T3-8-3
4
T4GB-03-08-003
COMPONENT OPERATION / Ride Control Valve
OPERATION
1. At neutral, port Pi and the ouput port are not
connected, blocked by the spool.
2. When the signal from the MC (Main Controller)
enters the solenoid, the solenoid is excited.
3. Solenoid pushes the spool with the force
corresponding to the signal from the MC, so port
Pi and the output port are connected, and pilot
pressure oil pushes the main spool.
4. When the main spool is pushed toward spring 2,
port A (on the bottom end of the lift arm cylinder)
and the ride control accumulator are connected,
and port B (on the rod end of the lift arm cylinder)
and port T are connected.
5. As a result, the pushing force of the lift arm
cylinder is absorbed by the accumulator, and the
load generated by the pushing up force is
absorbed by sucking up the hydraulic oil from the
tank port.
Section A*
Pilot Pressure
Spool
To Ride Control
Accumulator
Port Pi
Port A
Port B
Spring 1
Output Port
Spring 2
T4GB-03-08-006
Tank Port
Main Spool
*Refer to T3-8-1.
T3-8-4
COMPONENT OPERATION / Ride Control Valve
(Blank)
T3-8-5
COMPONENT OPERATION / Ride Control Valve
CHARGE-CUT SPOOL
Charge-cut spool accumulates the pressure oil in the
lift arm cylinder in the ride control accumulator, and
shuts down the pressure oil from the lift arm cylinder
when the ride control accumulator is accumulated to
the set pressure.
1. When the ride control is not in operation, the
pressure oil on the lift arm cylinder bottom end
flows to port X, passing the orifice through port A.
2. Pressure oil flowing into port X passes in the
spool of the charge-cut spool, and opening the
check valve, flows into port Y to be accumulated
in the ride control accumulator.
3. As Spool Sectional Area M is larger than Spool
Sectional Area N, when the ride control
accumulator is accumulated to the set pressure,
the pressure oil from port X pushes the spool
toward the spring.
4. When the spool moves toward the spring, the
passage of the pressure oil from the spool to port
Y is closed, and accumulating the ride control
accumulator is stopped.
T3-8-6
COMPONENT OPERATION / Ride Control Valve
During Accumulation of Accumulator
Orifice
Spring
Port A
Spool
Port X
To Ride Control
Accumulator
Port Y
Check Valve
T4GB-03-08-007
After Accumulation of Accumulator
Sectional Area M
Sectional Area N
T3-8-7
T4GB-03-08-008
COMPONENT OPERATION / Ride Control Valve
OVERLOAD RELIEF VALVE
Overload relief valve is installed for preventing hoses
and the ride control accumulator from being damaged
in case the pressure in the bottom end circuit of the lift
arm cylinder is suddenly raised by an external force or
something during operation of the lift arm cylinder.
Operation
1. Pressure at port HP (in the main circuit) works on
the pilot poppet, passing orifice A of the main
poppet and orifice B of the seat.
2. When the pressure at port HP rises to the setting
force of spring B, the pilot poppet opens, and
pressure oil flows to port LP, passing passage A
and the periphery of the sleeve.
3. At this moment, pressure difference arises
between port HP and the spring chamber caused
by orifice A.
4. When this pressure difference reaches the value
corresponding to the set force of spring A, the
main poppet opens, and the pressure oil at port
HP flows to port LP.
5. As a result, the pressure in the actuator circuit
lowers.
6. If the actuator circuit pressure lowers to the set
pressure, the main poppet is closed by the force
of spring A.
IMPORTANT: Never disassemble or adjust the
overload relief valve. Replace the
whole assembly, when necessary.
T3-8-8
COMPONENT OPERATION / Ride Control Valve
Normally:
Sleeve
Make-up Valve
Main Poppet
Orifice A
Orifice B
Seat
Passage A Spring B
HP
LP
Spring C
T176-03-03-012
Spring Chamber
Spring A
Pilot
Poppet
When Relieving:
Sleeve
Main Poppet
Orifice A
Orifice B
Seat
Passage A
Spring B
HP
LP
T176-03-03-013
Spring
Chamber
Spring A
T3-8-9
Pilot
Poppet
COMPONENT OPERATION / Ride Control Valve
RIDE CONTROL ACCUMULATOR
Ride control accumulator is installed in the
accumulation circuit of the ride control.
High-pressure nitrogen gas is contained in the
accumulator, and the pressure oil compresses the
nitrogen gas through the piston.
Compression of the nitrogen gas dampens shock of
the pressure oil due to pitching and the like of the lift
arm cylinder raising circuit.
IMPORTANT: Construction of the ride control
accumulator
does
not
allow
disassembly. Replace the whole
assembly, when necessary.
T4GB-03-08-009
T3-8-10
COMPONENT OPERATION / Ride Control Valve
DRAIN PLUG
Ride control valve is provided with the drain plug for
returning the pressure oil of the ride control
accumulator to the oil tank at the time of maintenance
or something.
When necessary, connect the accumulator port (port
SP) and the tank port (port T) by loosening the lock nut
first and the drain plug later.
CAUTION: Excessive loosening (More than 2
turns) of the drain plug can result in oil burst
due to removal of the drain plug itself.
Section B
*
Port SP
Lock Nut
Drain Plug
Relief Plug
Port T
*Refer to T3-8-1.
T3-8-11
Ｔ4ＧＢ-03-08-010
COMPONENT OPERATION / Ride Control Valve
(Blank)
T3-8-12
COMPONENT OPERATION / Drive Unit
OUTLINE
Drive unit consists of the transmission and the torque
converter.
Drive unit is connected with the engine. Power from the
engine is transmitted to the transmission through the
engine flywheel and the torque converter.
Torque Converter
T4GC-03-09-005
Transmission
T3-9-1
COMPONENT OPERATION / Drive Unit
TORQUE CONVERTER
Torque converter consists of the converter wheel
assembly, pump drive device, turbine shaft, and others.
In the converter wheel assembly, impeller (7) and
turbine (3) are mutually opposed with stator (4)
installed in between, and they are all contained in the
casing filled with oil.
Engine rotation is transmitted from the engine wheel to
the transmission through input plate (2), cover wheel
(1), impeller (7), turbine (3), and turbine shaft (11).
Hydraulic oil for the torque converter supplied from the
transmission control valve enters the converter wheel
through the oil passage of the stator support.
When impeller (7) is rotated by the engine rotation, oil
flows along the blade of impeller (7) toward the
periphery, and flows into the turbine (3). This oil flow
collides with the blade of turbine (3), and rotates
turbine (3) and turbine shaft (11). Also, the output
torque of turbine shaft (11) is generated by the reaction
force caused by the oil flow direction change due to
collision of oil with the blade of turbine (3).
Stator (4) always rectifies the oil flow coming out of
turbine (3) in the determined direction, and flows the oil
into impeller (7) for enlarging torque.
T3-9-2
COMPONENT OPERATION / Drive Unit
7
8
9
10
11
1
2
3
4
5
6
T4GC-03-09-001
1 - Cover Wheel
2 - Input Plate
3 - Turbine
4 - Stator
5 - Input Guide
6 - Stator Hub
7 - Impeller
8 - Impeller Hub
9 - Pump Drive Gear
T3-9-3
10 - Guide Carrier
11 - Turbine Shaft
COMPONENT OPERATION / Drive Unit
TRANSMISSION
Transmission so fuctions as to transform the rotation
speed and rotation direction of the power transmitted
from the torque converter.
Transmission is composed of the four clutch shaft
assemblies, the reverse gear, output shaft, parking
brake, control valve, and others.
Safety valve is installed at the inlet part of the hydraulic
oil for the torque converter, and relieves redundant oil
into the converter housing.
Input
Forward
Clutch
Reverse
Gear
Reverse
Clutch
Idler Gear
3rd & 4th
Speeds Clutch
1st & 2nd
Speeds Clutch
Output
T4GC-03-09-002
Transmission Gear Layout Drawing
(Viewed from Vehicle Front End）
T3-9-4
COMPONENT OPERATION / Drive Unit
Front View of Transmission
1
A
2
5
B
6
B
C
3
C
7
8
4
A
T4GC-03-09-003
1 - Breather
2 - from Oil Cooler
3 - Control Valve
4 - Oil Feed Port
5 - Charging Pump
6 - Rotation Sensor (A)
T3-9-5
7 - Rotation Sensor (B)
8 - Vehicle Speed Sensor
COMPONENT OPERATION / Drive Unit
Rear View of Transmission
1
D
D
2
3
9
8
7
E
6
4
Detail E
5
T4GC-03-09-004
Section DD
1 - Engine Speed Sensor
2 - Suction Tube
3 - Hose
4 - Strainer
5 - To Oil Cooler
6 - Converter Outlet Boss
7 - Oil Pressure Gauge Port
8 - Safety Valve
9 - Spring
T3-9-6
COMPONENT OPERATION / Drive Unit
Side View of Transmission
2
1
3
4
3
5
6
9
10
7
8
T4GC-03-09-005
1 - Converter Inlet Pressure
Port
2 - Regulator Valve
3 - Forward Clutch Pressure
Port
4 - Reverse Clutch Pressure
Port
5 - 1st Speed Clutch Pressure
Port
6 - 2nd Speed Clutch Pressure
Port
7 - 3rd Speed Clutch Pressure
Port
8 - 4th Speed Clutch Pressure
Port
9 - Parking Brake Release
Pressure Inlet
T3-9-7
10 - Parking Brake Pressure
Switch Port
COMPONENT OPERATION / Drive Unit
Cross-Sectional Drawing of Transmission
1
2
14
3
4
Section BB※
13
5
12
11
10
9
Section CC※
15
1234-
Charging Pump
Pump Drive Shaft
Forward Clutch
Distributor Cap
5678-
7
8
Section AA※
T4GC-03-09-006
16
Parking Brake
Front Output Flange
Output Shaft
Drain Plug
6
9 - Rear Output Flange
10 - 1st & 2nd Speeds Clutch
11 - Distributor Cap
12 - Idler Shaft
※Refer to T3-9-5
T3-9-8
13 - Torque Converter
14 - Reverse Clutch
15 - Distributor Cap
16 - 3rd & 4th Speeds Clutch
COMPONENT OPERATION / Drive Unit
Clutch Shaft
Clutch shaft assemblies contain clutch discs of the
respective speed shifts, and transmit or stop power.
1
2
3
4
5
A
6
7
8
9
10
11
B
12
13
Detail B
Detail A
1234-
Hub Gear
End Plate
Return Spring
Seal Ring (Inner)
567-
Bleed Valve
Seal Ring (Outer)
Piston
T4GC-03-09-007
8 - Disk
9 - Plate
10 - Hub Gear
T3-9-9
11 - Shaft
12 - Plug
13 - Seal Ring
COMPONENT OPERATION / Drive Unit
(Forward Clutch Shaft)
T4GC-03-09-008
(Reverse Clutch Shaft)
T4GC-03-09-009
T3-9-10
COMPONENT OPERATION / Drive Unit
(1st & 2nd Speeds Clutch Shaft)
T4GC-03-09-010
(3rd & 4th Speeds Clutch Shaft)
T4GC-03-09-011
T3-9-11
COMPONENT OPERATION / Drive Unit
Operation
In Operation
Clutch is operated by the pressure oil from the
transmission control valve.
Pressure oil transmitted from the transmission control
valve reaches the back of piston (7) through the oil
passage inside shaft (11). Oil passage is blocked
because the pressure oil pushes the bleed valve (5)
in piston (7) toward disc (8), and piston (7) is pushed
toward disc (8). Piston (7) transmits power to the
whole of shaft (11) and hub gear (1) connected by
pressing and adhering disc (8) and plate (9).
Not in Operation
When pressure oil is not transmitted from the
transmission control valve, bleed valve (5) is opened
by the centrifugal force of shaft (11), so the risidual
pressure oil in the piston and others are discharged
toward disc (8). Piston (7) is pushed back by the
return spring (3) between plates (9).
There arises a clearance between disc (8) and plate
(9), so shaft (11) and clutch hub gear (1) rotate
separately, and power is not transmitted.
T3-9-12
COMPONENT OPERATION / Drive Unit
In Operation
1
8
9
7
11
Detail A
From
Control Valve
A
T4GC-03-09-012
Not in Operation
1
9
3
8
7
5
11
Detail B
B
T4GC-03-09-013
1 - Hub Gear
3 - Return Spring
57-
Bleed Valve
Piston
89-
T3-9-13
Disk
Plate
11 - Shaft
COMPONENT OPERATION / Drive Unit
Transmission of Power
1
2
Input
Reverse
Gear
4
Forward
Clutch
Reverse
Clutch
5
3
7
9
1st & 2nd
Speeds Clutch
Idler Gear
8
6
3rd & 4th
Speeds Clutch
12
10
13
14
11
15
16
Output
1234-
Input Gear
Reverse Gear
F-R Gear
F Hub Gear
5678-
F-R Gear
R Hub Gear
Idler Gear
Idler Gear
9 - 2nd Hub Gear
10 - 1st Hub Gear
11 - Low-range Gear
12 - 4th Hub Gear
T3-9-14
T4GC-03-09-002
13 - 3rd Hub Gear
14 - High-range Gear
15 - Output Gear
16 - Output Gear
COMPONENT OPERATION / Drive Unit
5
6
Reverse Clutch
2
1
4
Forward Clutch
8
10
3
11
7
9
1st & 2nd
Speeds Gear
16
15
14
12
13
T4GC-03-09-014
T3-9-15
COMPONENT OPERATION / Drive Unit
Forward 1st Speed
In the case of forward 1st speed, the forward clutch
and the 1st speed part of the 1st & 2nd speeds clutch
are connected. Torque converter transmits torque to
F hub gear (4) geared to the input gear (1).
Torque from F hub gear (4) is transmitted to the 1st
speed hub gear (10) through F - R gear (3), the idler
gear (7), and the idler gear (8).
Furthermore, torque is outputted from the 1st hub
gear (10) to the low-range gear (11), and eventually
outputted to the output gear (16).
1
Input
4
Forward
Clutch
3
7
1st & 2nd
Speeds
Clutch
8
10
11
16
Output
Power Flow: Forward 1st Speed
T3-9-16
T4GC-03-09-015
COMPONENT OPERATION / Drive Unit
1
4
Forward Clutch
3
8
10
7
11
1st & 2nd
Speeds Clutch
16
T4GC-03-09-016
1 - Input Gear
3 - F−R Gear
47-
F Hub Gear
Idler Gear
8 - Idler Gear
10 - 1st Speed Hub Gear
T3-9-17
11 - Low-Range Gear
16 - Output Gear
COMPONENT OPERATION / Drive Unit
Forward 2nd Speed
In the case of forward 2nd speed, the forward clutch
and the 2nd speed part of the 2nd speed clutch are
connected. Torque converter transmits torque to F
hub gear (4) geared to input gear (1).
Torque from F hub gear (4) is transmitted to the 2nd
speed hub gear (9) through F - R gear (3) and idler
gear (7).
Furthermore, torque is outputted from 2nd hub gear
(9) to low-range gear (11), and eventually outputted
to output gear (16).
1
Input
4
Forward
Clutch
3
7
1st & 2nd Speeds
Clutch
9
11
16
Output
Power Flow: Forward 2nd Speed
T3-9-18
T4GC-03-09-017
COMPONENT OPERATION / Drive Unit
1
4
Forward Clutch
3
7
11
1st & 2nd Speeds
Clutch
16
9
T4GC-03-09-018
1 - Input Gear
3 - F−R Gear
47-
F Hub gear
Idler Gear
9 - 2nd Speed Hub Gear
11 - Low-range Gear
T3-9-19
16 - Output Gear
COMPONENT OPERATION / Drive Unit
Forward 3rd Speed
In the case of forward 3rd speed, the forward clutch
and the speed 3 part of the 3rd & 4th Speeds clutch
are connected. Torque converter transmits torque to
F hub gear (4) geared to the input gear (1).
Torque from F hub gear (4) is transmitted to 3rd
Speed hub gear (13) through F - R gear (3) and idler
gear (8).
Furthermore, torque is outputted from 3rd hub gear
(13) to high-range gear (14), and eventually
outputted to output gear (15).
1
Input
4
Forward
Clutch
3
7
8
13
14
15
Output
Power Flow: Forward 3rd Speed
T3-9-20
T4GC-03-09-019
COMPONENT OPERATION / Drive Unit
1
4
3
Forward
Clutch
8
7
15
14
3rd & 4th
Speeds Clutch
13
T4GC-03-09-020
1 - Input Gear
3 - F−R Gear
47-
F Hub Gear
Idler Gear
8 - Idler Gear
13 - 3rd Hub Gear
T3-9-21
14 - High-Range Gear
15 - Output Gear
COMPONENT OPERATION / Drive Unit
Forward 4th Speed
In the case of forward 4th speed, forward clutch and
the 4th speed part of 3rd & 4th speeds clutch are
connected. Torque converter transmits torque to F
hub gear (4) geared to input gear (1).
Torque from F hub gear (4) is transmitted to 4th
speed hub gear (12) through F - R gear (3) and the
idler gear (7).
Furthermore, torque is outputted from the 4th hub
gear (12) to the high-range gear (14), and eventually
outputted to the output gear (15).
1
Input
4
Forward
Clutch
3
3rd & 4th
Speeds Clutch
7
12
14
15
Output
Power Flow: Forward 4th Speed
T3-9-22
T4GC-03-09-021
COMPONENT OPERATION / Drive Unit
1
4
Forward Clutch
3
7
15
12
3rd & 4th
Speeds Clutch
14
T4GC-03-09-022
1 - Input Gear
3 - F−R Gear
47-
F Hub Gear
Idler Gear
12 - 4th Hub Gear
14 - High-Range Gear
T3-9-23
15 - Output Gear
COMPONENT OPERATION / Drive Unit
Reverse 1st Speed
In the case of reverse 1st speed, the reverse clutch
and the 1st Speed part of the 1st & 2nd Speeds
clutch are connected. Torque converter transmits
torque to R hub gear (6) from reverse gear (2) geared
to input gear (1).
Torque from R hub gear (6) is transmitted to 1st
speed gear (10) through F - R gear (5), idler gear (7),
and idler gear (8).
Furthermore, torque is outputted from 1st hub gear
(10) to low-range gear (11), and eventually outputted
to output gear (16).
Processes of the idler gear and after are applied to
the other reverse speed shifts similarly.
1
2
Input
Reverse
Clutch
7
6
5
8
1st & 2nd
Speeds Clutch
10
11
16
Output
Power Flow: Reverse 1st Speed
T3-9-24
T4GC-03-09-023
COMPONENT OPERATION / Drive Unit
5
Reverse Clutch
6
2
1
7
8
10
11
1st & 2nd
Speeds Clutch
16
T4GC-03-09-024
1 - Input Gear
2 - Reverse Gear
5 - FR Gear
678-
R Hub Gear
Idler Gear
Idler Gear
10 - 1st Hub Gear
11 - Low-Range Gear
16 - Output Gear
T3-9-25
COMPONENT OPERATION / Drive Unit
TRANSMISSION REGULATOR VALVE
The transmission regulator valve so controls the
pressure oil from the charging pump as to be constant,
and supplies it to the transmission control valve for
controlling the clutch.
Pressure oil entering the P port of the regulator valve
from the charging pump passes the small hole of the
regulator spool, and enters the back chamber of the
spool. When the oil pressure entering the back
chamber rises higher than the pressure corresponding
to the spring force, the regulator spool moves toward
the spring, and the pressure oil at the P port flows from
the outlet port to the torque converter. This movement
of the spool keeps the pressure at port P constant. port
P is connected to the transmission control valve, and
pressure oil of a constant pressure is supplied to the
transmission control valve. The pressure oil from Port
P passes the oil passage inside the transmission
casing, and is transferred to the transmission control
valve. Oil overflow passes the oil passage in the
mission case, and is transferred to the torque
converter.
T3-9-26
COMPONENT OPERATION / Drive Unit
Normally
Small Hole of
Regulator Spool
Regulator Spool
Spring
From
Charging Pump
T4GC-03-09-025
When overflowing
Regulator Spool
Spring
To Transmission
Control Valve
From
Charging Pump
To Torque
Converter
T3-9-27
T4GC-03-09-026
COMPONENT OPERATION / Drive Unit
TRANSMISSION CONTROL VALVE
Transmission control valve transfers to each clutch the
oil sent from the regulator valve, and makes
changeover of the vehicle travel direction and speed
shift.
Transmission control valve is composed of the valve
body and the solenoid valves for the respective
clutches, and controls the clutch oil pressure by
operating the shift lever to actuate each solenoid valve,
and by moving the modulation spool of the valve body.
Proportional solenoid valves are controlled about their
oil pressure by the electric signal transmitted from the
controller, and can obtain oil pressure waves of
different characteristics depending on the vehicle
condition.
T3-9-28
COMPONENT OPERATION / Drive Unit
Control Valve
4th Speed Clutch
3rd Speed Clutch
2nd Speed Clutch
1st Speed Clutch
Reverse Clutch
Forward Clutch
Regulator
Valve
Clutch
Lubrication
Torque
Converter
Cooler
Torque
Converter
Torque
Converter
Safety
Valve
Filter
Charging
Pump
T4GC-03-09-027
T3-9-29
COMPONENT OPERATION / Drive Unit
9
8
7
6
5
4
T4GC-03-09-028
3
1 - Cover
2 - Valve Body
3 - Solenoid Body
2
4 - 4th Speed Proportional
Solenoid Valve
5 - 3rd Speed Proportional
Solenoid Valve
6 - 2nd Speed Proportional
Solenoid Valve
7 - 1st Speed Proportional
Solenoid Valve
8 - Reverse Proportional
Solenoid Valve
9 - Forward Proportional
Solenoid Valve
T3-9-30
1
COMPONENT OPERATION / Drive Unit
1
2
3
24
4
5
23
6
7
8
22
9
21
10
11
12
20
13
14
19
15
16
17
18
T4GC-03-09-029
From
Charging Pump
1 - Solenoid Body
7 - Emergency Reverse Spool
2 - Valve Body
8 - Reverse Modulation Spool
3 - Cover
9 - Reverse Modulation Spring
4 - Emergency Forward Spool
10 - 1st Speed Modulation
Spool
11 - 1st Speed Modulation
Spring
12 - Emergency 2nd Speed
Spool
5 - Forward Modulation Spool
6 - Forward Modulation Spring
13 - 2nd Speed Modulation
Spool
14 - 2nd Speed Modulation
Spring
15 - 3rd Speed Modulation
Spool
16 - 3rd Speed Modulation
Spring
17 - 4th Speed Modulation
Spool
18 - 4th Speed Modulation
Spring
T3-9-31
19 - 4th Speed Proportional
Solenoid Valve
20 - 3rd Speed Proportional
Solenoid Valve
21 - 2nd Speed Proportional
Solenoid Valve
22 - 1st Speed Proportional
Solenoid Valve
23 - Reverse Proportional
Solenoid Valve
24 - Forward Proportional
Solenoid Valve
COMPONENT OPERATION / Drive Unit
Operation
Modulation mechanism enables smoother speed
change by varying the pressure increase wave or
pressure decrease wave of each clutch depending on
the the vehicle condition (engine speed, vehicle
speed, and others).
Vehicle condition is judged by analyzing the
information (electric signal) sensed by the engine
speed sensor, vehicle speed sensor, and shift lever
utilizing the mission controller, and the electric signal
is transmitted from the controller to the proportional
solenoid valve depending on the shift change.
Proportional solenoid valve regulates the oil pressure
depending on the electric signal transmitted from the
controller, and transfers oil to the modulation spool.
Modulation spool regulates the clutch oil pressure
also, depending on the oil pressure transmitted from
the proportional solenoid valve, and transfers oil to
the clutch piston.
In Pressure
Decrease
Oil
Pressure
In Pressure
Increase
Time
Transition Point
T4GC-03-09-030
Clutch Oil Pressure Wave
T3-9-32
COMPONENT OPERATION / Drive Unit
At Neutral
Pressure oil regulated by the regulator valve flows to
the oil passage (a) of the transmission control valve,
and is divided flowing into the oil passage (b) leading
to the proportional solenoid valve (1) and the oil
passage (c) of the modulation spool (2).
Oil does not flow from the oil passage (b) to the oil
passage (d) because the electric signal to be
transmitted from the controller to the proportional
solenoid valve (1) is stopped in the neutral condition.
Also, oil is confined between the oil passage (c) and
the oil passage (e) of the piston, so the clutch
pressure is not raised, becoming the neutral
condition.
1
d
2
To Piston
T4GC-03-09-031
c
a
From
Regulator Valve
b
1 - Proportional Solenoid
Valve
2 - Modulation Spool
T3-9-33
e
COMPONENT OPERATION / Drive Unit
Shift to 2nd Speed from Neutral (In Pressure
Increase)
• In Process of Clutch Connection
(Refer to Oil Pressure Wave A of T3−9−32.)
2. Also, the oil transferred to the oil passage (e)
passes back chamber (g) of modulation spool (2),
and is sent to back chamber (h) of the modulation
spool (2).
As modulation spring (3) is assembled in back
chamber (h) of modulation spool (2), overcomes
the oil pressure in oila passage (e), and moves
modulation spool (2) right, closing oil passage (e)
temporarily.
When the transmission is shifted by the lever,
electric signal is transmitted from the controller to
proportional solenoid valve (1).
During oil pressure wave A, the oil transferred to
oil passage (b) of proportional solenoid valve (1)
is regulated to the pressure corresponding to the
electric signal of the controller, and is transferred
to the oil passage (d).
1. Oil transferred to oil passage (d) is transferred to
pressure chamber (f) of the modulation spool (2),
overcomes the force of modulation spring (3), and
moves modulation spool (2) to the left column.
As a result, oil is transferred from the oil passage
(c) to oil passage (e) of the clutch piston, and the
clutch pressure is raised.
1
3
h
Electric current from the controller is enlarged
gradually, and repeats the processes in 1. and 2. As a
result, the clutch oil pressure is gradually raised.
g
d
f
To 2nd Speed
Clutch
T4GC-03-09-032
c
a
b
1 - Proportional Solenoid
Valve
2 - Modulation Spool
3 - Modulation Spring
T3-9-34
e
2
COMPONENT OPERATION / Drive Unit
• At End of Clutch Connection
• In Shift Down Condition from Forward 2nd Speed
(Refer to Pressure Oil Wave B of T3-9-32.)
to 1st Speed [at DSS]
Finally, pressures in pressure chamber (f) and
pressure chamber (h) become equal.
Spring (3) is assembled in pressure chamber (h),
but as the spool diameter in the pressure
chamber (f) is larger than the diameter
corresponding to the pressure chamber (h) plus
spring (3) force, the modulation spool (2) is
pushed to fully stroke. Therefore, completely
opening oil passage (c) and the oil passage (e).
(Refer to the drawing below.)
As a result, the clutch pressure and the regulator
pressure become equal and constant.
Pressure increase of the 1st Speed clutch
pressure is similar to “Speed Shift Change from
Neutral to 2nd Speed.”
Pressure decrease of the 2nd Speed clutch
pressure is operated reversely, and the clutch
pressure is gradually lowered by gradually
lowering the electric signal (electric current value)
from the high condition.
Overlapping the clutch pressure of the partner
clutch pressure by gradually raising the 1st Speed
clutch pressure and gradually lowering the 2 nd
clutch pressure eliminates lack of torque at the
time of shift down in digging, and achieves
smooth workability.
Proportional solenoid valve and the modulation
spool organize a set in terms of construction, and
enables obtaining constantly best modulation
pressure wave by combining the pressure
increase characteristics and the pressure
decrease characteristics. (Refer to Clutch Oil
Pressure Wave on T3-9-32.)
3
To 2nd
Speed Clutch
2
f
T4GC-03-09-033
c
h
1 - Modulation Spool
2 - Modulation Spring
T3-9-35
e
COMPONENT OPERATION / Drive Unit
MANUAL SPOOL (EMERGENCY TRAVEL
SPOOL)
In case the solenoid valve cannot be operated caused
by electric disorders (e.g.: disconnection), changeover
of the control valve to Forward 2nd Speed or Reverse
2nd Speed is possible by manually operating this spool.
This spool is used for self-traveling of the vehicle to the
place of maintenance in an emergency or something.
IMPORTANT: Prior to use of the manual spool,
stop the engine. Operating the
manual spool while the engine is
running is dangerous because the
vehicle can begin moving.
Operation
• Forward 2nd Speed
When changeover to Forward 2nd Speed is made,
push in the forward emergency travel spool (3)
and 2nd emergency travel spool (5) each by 5
mm, and turn them 90 degrees, keeping pushing
them.
Oil regulated to the regulator pressure flows into
the passage (b) through the passage (a) opened
by the forward modulation spool, and flows to the
forward clutch to connect the clutch.
Similarly, the 2nd clutch also flows into the oil
passage (f) through the oil passage (e) opened by
the 2nd modulation spool (7), and flows to the 2nd
clutch to connect the clutch.
• Reverse 2nd Speed
When the forward emergency travel spool (3) is
turned by 90 degrees, the spool returns to the
original position by the force of the spring (1).
Similarly to forward 2nd speed, in reverse 2nd
speed, push in the reverse emergency travel
spool (5) by 5 mm, and turns it 90 degrees.
Oil regulated to the regulator pressure flows into
the oil passage (d), through the oil passage (c)
opened by the reverse modulation spool (4), and
flows to the reverse clutch to connect the clutch.
IMPORTANT: Avoid simultaneous use of the
forward emergency travel spool (3)
and the reverse emergency travel
spool (5).
Breakage of the clutch can be
caused.
T3-9-36
COMPONENT OPERATION / Drive Unit
From Regulator
Valve
c
1
a
Forward
Clutch
b
2
3
4
5
d
Reverse
Clutch
f
2nd
Clutch
6
7
e
• In Operation of Manual Spool
From
To Each
Regulator Valve Clutches
T4GC-03-09-034
1 - Modulation Spring
3-
Emergency Forward Spool
5-
Emergency Reverse Spool
2 - Forward Modulation Spool
4-
Reverse Modulation Spool
6-
Emergency 2nd Speed
Spool
T3-9-37
7-
2nd Speed Modulation
Spool
COMPONENT OPERATION / Drive Unit
PROPORTIONAL SOLENOID VALVE
Operation
Proportional splenoid valve is used as a pilot valve for
the clutch oil pressure, and transfers oil to the
modulation spool by receiving the electric signal from
the controller, and by raising or lowering the oil
pressure.
• At Neutral: Spool (1) is pushed right by the spring
S
T
P
1
(2), and outlet port S is connected with tank port
T.
• At Excitement: Solenoid valve (3) pushes the
spool (1) left with a force in proportion to the
electric current flowing at the solenoid (3). Pilot
pressure oil flows to output port S from port P, and
the pressure at output port S rises.
This pressure at output port S works on the
shoulder part ‘a’ of the spool (1). Shoulder part ‘a’
has different sectional areas, and generates a
force to push the spool (1). When the pressure at
output port S rises, and the force pushing the
spool (1) right becomes larger than the force due
to the solenoid (3) to push the spool (1) left, the
spool (1) is returned to the right, the passage
between output port S and port P is closed, and
the pressure at output port S stops rising.
2
3
a
a
T107-02-07-005
1 - Spool
2-
Spring
3-
T3-9-38
Solenoid
COMPONENT OPERATION / Axle
OUTLINE
Axle consists of the differential, final drive, axle shaft,
brake, and others.
Axle Shaft
Final
Drive
Power from the transmission is transmitted to the front
axle and the rear axle through the propeller shaft. Inside the axle, power is transmitted to the differential,
and divided into left and right, and drives the axle
shaft and the wheels through the final drive.
Differential
Brake
Brake
T4GB-03-10-001
T3-10-1
COMPONENT OPERATION / Axle
DIFFERENTIAL
Differential enables the left and the right drive wheels
to rotate at different rotating speeds in steering of the
vehicle body or traveling on bumpy roads.
4
5
6
7
8
9
10
11
3
2
12
1
13
14
15
16
17
18
19
20
21
123456-
Brake Ring
Brake Disc
Piston
Side Gear
Case A
Ring Gear
7 - Pinion Gear
8 - Spider
9 - Case B
10 - Roller Bearing
11 - Differential Body
12 - Gear & Shaft
13 - Adjusting Nut
14 - Bearing Retainer
15 - Pinion Shaft
16 - Roller Bearing
17 - Bearing Cage
18 - Spacer
T3-10-2
19 - Roller Bearing
20 - Oil Seal
21 - Flange
T4GB-03-10-002
COMPONENT OPERATION / Axle
Function
• Purpose of Differential
When the vehicle body is steered, the inner wheel
turns with a smaller radius, so the outer wheel
needs to rotate faster for smooth steering.
Suppose driving the rear wheel by directly installing
the gear to the propeller shaft with a shaft having no
differential.
In this case, the outer wheel and the rear wheel rotate the same amount. In other words, when the
vehicle body is steered, the outer wheel cannot rotate more than the inner wheel, and as a result,
skidding sideways or tire wear takes place. Also,
the axle shaft is subjected to torsional stress, resulting in unstable transmission of drive force.
On the other hand, in case a differential is installed,
the inner and the outer wheels can rotate at different speeds, and the problem mentioned above can
be eliminated.
Extension Line of
Rear Wheel Centers
In Turning of Vehicle Body
In Traveling of Vehicle Body on Rough Roads
T202-03-05-005
T3-10-3
COMPONENT OPERATION / Axle
• Principle of Differential
Operation principle of the differential is explained
here comparing it to the racks and the pinion gear
in the drawing.
When the load W is equally applied to the racks A
and B, if C is moved upward by the distance of H,
the racks A and B both move by the same distance
of H in unison with the pinion.
If moved by removing the load to the rack B, the
pinion rotates on the rack A (with load applied), and
moves the rack B upward. At this time, the distance
the rack B moves is longer than the distance the
pinion moves rotating.
Distance the rack B moves can be calculated using
the equation of H+H=2H. This principle is applied to
the differential.
W
W
W
C
C
H
H
H
2H
Rack (A)
Rack (B)
Rack (A)
Pinion
• Operation of Differential
Rack (B)
Pinion
T202-03-05-006
In Traveling Straight
In case resistances applied to the axle shafts (7)
and (8) connected by spline to the differential side
gears (2) and (3) are the same, or in case the vehicle body is traveling straight on plane roads, the differential pinion gears (1) and (4) remain unrotated.
Differential pinion gears (1) and (4) and the side
gears (2) and (3) remain fixed by being mutually
geared, and rotate in unison with the housing (6)
connected with the ring gear (9).
In case the constituent portion of the whole is rotating solidly like this, the differential function of the
differential does not work, but gears (1), (2), (3),
and (4) play only the role of joints for connecting the
axle shafts (7) and (8).
10
9
1
8
2
3
4
7
6
T487-03-06-014
T3-10-4
COMPONENT OPERATION / Axle
In Steering
When the vehicle body swings, uneven resistances
are applied to the drive wheels. Therefore, caused by
the difference of the resistances applied to the inner
and outer wheels, the differential pinion gears (1) and
(4) begin revolving on the side gears (2) and (3), each
rotating round the pinion shaft. As a result, in case the
resistance force applied to the shaft (7) is large, the
pinion gears (1) and (4) rotate in the same direction
as the rotational direction on the side gear (2) of the
shaft (7). And the speed of the shaft (7) is lowered,
and the amount of the speed reduction is applied to
the shaft (8), working the differential function.
Suppose the ring gear (9) is driven by the drive pinion
(10) at the speed of 100. In the condition of the vehicle body traveling straight, the drive wheels on the
both sides rotate at the same speed.
However, in case the vehicle body swings, and the
speed of the right drive wheel is lowered to 90, the left
wheel turns at the speed of 100+(100−90)=110 because the speed of 10(100−90=10) is added to the
speed of the left wheel.
If the ring gear (9) rotates at 100, the summation of
the speeds of the left and right wheels becomes always 200 regardless of movement of the respective
wheels.
T3-10-5
10
9
1
8
2
3
4
7
6
T487-03-06-014
COMPONENT OPERATION / Axle
TORQUE PROPORTIONING DIFFERENTIAL (TPD)
Wheel loader is operated mostly on roads of bad conditions. In case of skidding, working efficiency and tire
lives are lowered. In order to avoid lowering of working efficiency and tire lives, the axle is provided with
the torque proportioning differential.
Differential pinion gear of the torque proportioning differential has an odd number of teeth, and the differential pinion gear and the side gear have special tooth
profiles. Therefore, the difference of the road resistances to the left and right tires causes deviation of
the gearing locations between the differential pinion
gear and the left and right side gears, and the drive
force transferred to the left and right tires changes.
Differential Pinion Gear
Right Side Gear
Left Side Gear
Forward Rotation
T3-10-6
T487-03-06-015
COMPONENT OPERATION / Axle
Traveling Straight with the Same Resistances to
Left and Right Tires
In case resistances to the left and right tires are the
same, the distances ‘a’ and ‘b’ from the differential
pinion gear center to the respective contact points of
the left and right side gears are the same. Therefore,
the differential pinion gear and the left and right side
gears solidly rotate toward forward, and the drive
forces of the left and right tires become the same.
Differential
Pinion Gear
Left Side Gear
Right Side Gear
T487-03-06-016
Traveling on Soft Roads (Different Resistances to
Left and Right Tires)
In traveling on soft roads, if the left tire skids, the
side gear on the left tire receiving little resistance
tends to rotate more forward than the right side gear.
This rotation causes deviation of the contact points
of the differential pinion gear and the left and right
side gears in the torque proportioning differential.
In case the left side gear rotates slightly more forward than the right side gear, the distance ‘a’ of the
contact point of the differential pinion gear and the
left side gear is lengthened. Correlation of the forces
at this time is as follows. a×TA (force applied to the
left side gear) = b×TB (force applied to the right side
gear).
Until the difference of the road resistances exceeds
certain value, the differential pinion gear does not
roate, but the left and right side gears rotate at the
same speed solidly. Besides, the left tire does not
rotate reduntantly, and does not skid. (Right tire can
have drive force larger than the left tire.) Therefore,
tire lives are prolonged, and working efficiency is improved.
Differential
Pinion Gear
Left Side Gear
T3-10-7
Right Side Gear
T487-03-06-017
COMPONENT OPERATION / Axle
LIMITED SLIP DIFFERENTIAL (LSD)
(Optional)
Operation Principle
Wheel loader, as required by the kind of work, must
be operated in places where skidding takes place
easily like sand and muddy soil. In places like these,
Tires can slip even if the torque proportioning differential (TPD) is installed. Rotation is transmitted to the
slipping tire, but not to the tires contacting the earth,
so not only the funtion of the wheel loader is worsened, but the tire lives are shortened.
In order to avoid this, the limited slip differential (LSD)
provided with the differential movement restriction device for avoiding different movement of the left and
right wheels is adopted. Drive force transmitted to the
left and right tires further changes.
LSD is so constructed that the clutch disc is inserted
between the pressure ring supporting the spider with
the cam and the case, which makes restriction of different movement by keeping the tire speeds the
same by the resistances of the friction surfaces. Also,
the variation of the dive force transmitted to the left
and right tires is made larger than the TPD.
Ring Gear
Pressure Ring
Side Gear
Pressure Plate
Clutch Disc
Case
Spider
Pinion Gear
T4GB-03-10-003
T3-10-8
COMPONENT OPERATION / Axle
Traveling Straight with the Same Road Resistances to Left and Right Tires
As the differential pinion gear and the left and right
pinion gears rotate solidly, the drive forces of the left
and right tires are the same similarly to the TPD.
Traveling on Soft Roads (Different Road Resistances to Left and Right Tires)
Drive force is transmitted to the case, pressure ring,
and spider through the ring gear. At this time, the
spider having the cam construction pushes the
pressure ring with the thrust P. Clutch disc is geared
with the case through the pressure ring. Side gears
fitted to the clutch disc by spline rotate solidly with
the case, and the left and right gears rotate at the
same speed.
Like this, the left and right axle shafts fitted to the
side gears by spline tend to rotate solidly with the
case, and the differential movement restriction works.
In case the drive force provided for the skidding tire
is larger than the road resistance, part of the torque
of the skidding tire is added to the tire contacting the
road by the differential movement restriction (because of the same speed of the left and right tires),
and the tire contacting the road is provided with
more torque.
Until the difference of the resistances between the
left and right tires exceeds certain value (until the
clutch disc begins to slip), the left and right gears
solidly rotate at a constant speed. On such soft
roads, the drive force increases by 1.5 times the
value for the TPD if the LSD is provided.
T3-10-9
Clutch Disc
Pressure Plate
Spider
Pressure Ring
T4GB-03-10-004
COMPONENT OPERATION / Axle
SERVICE BRAKE
Brake adopted is the wet type multi-disc brake, and is
assembled in the differential body of the axle. Four
wheels of this vehicle has all this disc brake.
• In Operation of Brake
Oil pressure from the brake valve works on the
back of brake piston (5) to move brake piston(5),
and brake disc (3) and brake ring (2) is compressed.
Inner surface of brake disc (3) is fitted by spline to
shaft (8) through disk hub (7). Also, the outer surface of brake ring (2) is fixed to differential body (4).
Therefore, the rotation of the pushed and compressed brake disc (3) stops, restricting the vehicle.
• In Release of Brake
When the oil pressure from the brake valve is decreased, brake piston(5) is returned by return
spring (6), and brake disc (3) is freed. Restriction of
the vehicle is released.
T3-10-10
COMPONENT OPERATION / Axle
1
2
2
3
3
2
Brake Oil
Pressure
4
5
6
7
8
T4GB-03-10-005
1 - End Plate
2 - Brake Ring
34-
Brake Disc
Differential Body
56-
• Operation
1
2
Brake Piston
Return Spring
78-
Disc Hub
Shaft
3
2 To
• Release
3
2
3
2
1
From
Brake Valve
5
2
3
2
Brake Valve
5
6
6
T4GB-03-10-007
T3-10-11
T4GB-03-10-008
COMPONENT OPERATION / Axle
FINAL DRIVE / AXLE SHAFT
Final drive is the device for finally decreasing the
speed in the power transmission system, and of the
planetary gear type. As for power transmission, the
power from the differential, transmitted from the shaft,
rotates the three planetary gears in the ring gear, and
transmits rotation of the planetary carrier to the axle
shaft through the planetary carrier.
Final
Drive
Axle Shaft
Ring Gear
Shaft
Housing
Planetary Carrier
Planetary Gear
T4GB-03-10-006
T3-10-12
COMPONENT OPERATION / Brake Valve
OUTLINE
Brake valve is operated by the brake pedal. (Refer to
the Brake Circuit of SYSTEM/Hydraulic System)
Brake valve sends pilot pressure depending on the
extent of stepping the brake pedal, and operates the
fore wheel or rear wheel service brake.
Brake Pedal
Brake Valve
T4GB-03-11-001
T3-11-1
COMPONENT OPERATION / Brake Valve
Component Layout
1
2
3
4
Port T
5
6
Port BR1
Port M1
11
7
Port BR2
Port M2
10
8
9
T4GB-03-11-002
1 - Pedal
2 - Roller
3 - Spool Input
4 - Spring
5 - Spring
6 - Spring
7 - Spool
8 - Spool
9 - Spring
T3-11-2
10 - Plunger
11 - Plunger
COMPONENT OPERATION / Brake Valve
1
5
7
From Port M2
of Charging Block
M1
From Port M2
of Charging Block
M2
BR1
BR2
T
To Front
Service Brake
To Rear
Service Brake
8
9
T4GB-03-11-003
T3-11-3
COMPONENT OPERATION / Brake Valve
OPERATION
Not in Operation of Brake
1. When the brake valve is not in operation, the ports
(BR1 and BR2) are connected with the tank port
(T) because the spring (9) returns the spools (7
and 8) to the non-operating position.
2. Ports (M1 and M2) and the brake ports (BR1 and
BR2) are blocked by the spools (7 and 8), and the
pressure oil in the service brake accumulator is
retained.
T
M1
BR1
M2
BR2
7
8
9
T4GB-03-11-004
T3-11-4
COMPONENT OPERATION / Brake Valve
In Operation of Brake
1. When the brake valve is stepped, spool input (3)
is pushed through roller (2).
Spool input moves the spools (7 and 8) forward
through the spring (5).
2. When the spools (7 and 8) moves forward, ports
(BR1 and BR2) and port (T) are disconnected.
When spools (7 and 8) are further moved forward,
the ports (BR1 and BR2) and the ports (M1 and
M2) are connected, and the pressure oil of the
accumulator flows out from the ports (BR1 and
BR2), beginning braking operation.
3. Pressure oil on the ports (BR1 and BR2) end
passes the orifices installed in spools (7 and 8),
and works on the built-in plungers (10 and 11) of
spools (7 and 8) as the return force (oil pressure
rection force) of the spools (7 and 8). Summation
of this oil pressure reaction force and the load of
spring (9) balances with the load of spring (5), and
controls the brake oil pressure on the brake ports
(BR1 and BR2) end.
4. Deflection and load of spring (5) are fed back as
the stroke and operating force of the brake pedal,
and provides the operator with virtual operation
feeling.
2
3
5
T
BR1
M1
7
11
BR2
M2
8
10
9
T4GB-03-11-005
T3-11-5
COMPONENT OPERATION / Brake Valve
In Brake Release
1. When the operating force is released, spool input
(3) is pushed back by spring (4).
2. Compression of spring (5) is released, and spools
(7 and 8) are returned to the non-operation
position by the summation of the oil pressure
reaction force working on the plunger and load of
the spring (9).
3. At this time, the ports (BR1 and BR2) and the port
(M1 and M2) are blocked by the spools (7 and 8),
and the ports (BR1 and BR2) are relieved to the
port (T).
Pressure oil on the ports (BR1 and BR2) end is
discharged to the port (T), and the brake operation
is released.
3
4
T
5
BR1
M1
7
BR2
M2
8
9
T4GB-03-11-006
T3-11-6
COMPONENT OPERATION / Others
PILOT SHUTOFF VALVE
Pilot shutoff valve is a munually operated changeover
valve, and by operating the pilot control shutoff lever,
rotates the spool to turn ON and OFF the pilot pressure
to the pilot valve.
Section Z-Z
Shutoff Position of Pilot Shutoff Valve
At OFF of the pilot shutoff valve, the pressure oil from
the pilot pump does not flow to the pilot valve. Oil on
the pilot valve end flows to the hydraulic oil tank.
At ON of Pilot Control Shutoff Lever
At ON of the pilot shutoff valve, the drain circuit is
blocked, and the pressure oil from the pilot pump
flows to the pilot valve.
From Brake/
Pilot Pump
To Pilot
Valve
T4GB-03-12-001
A2
A1
Z
T1
T2
T3
P
Z
A3
A4
T4
A5
T4GB-03-12-002
A1 - Extra
A2 - Extra
A3 - To Pilot Valve (Optional)
A4 - To Pilot Valve
A5 - Extra
P - From Brake/Pilot Pump
T1 - From Pilot Valve
T2 - Extra
T3-12-1
T3 - From Pilot Valve (Optional)
T4 - To Hydraulic Oil Tank
COMPONENT OPERATION / Others
PROPELLER SHAFT
Propeller shafts are installed between the transmission
and the front axle, and between the transmission and
the rear axle, respectively.
Propeller shaft transmits the power from the
transmission to the front axle and the rear axle. Joint
adopted is the universal joint most commonly used.
Between Front Axle and Transmission
Universal Joint
T4GB-03-12-003
Between Transmission and Rear Axle
Universal Joint
T4GB-03-12-004
T3-12-2
COMPONENT OPERATION / Others
EMERGENCY STEERING CHECK BLOCK
Emergency steering check block is installed between
the main pump and steering valve.
Built-in check valve is provided for preventing the
delivery oil of the emergency steering pump from
flowing to the main pump.
A
A: from main pump
B: from emergency steering pump
C: pressure sensor port
D: to steering valve
E: to hydraulic oil tank
B
Section X-X
B
A
C
Y
D
Section Y-Y
A
Y
E
C
D
E
X
X
T4GB-03-12-007
T3-12-3
COMPONENT OPERATION / Others
EMERGENCY STEERING PUMP
(OPTIONAL)
Emergency steering pump is installed to be started in
case supply of the pressure oil from the main pump is
suddenly stopped for one reason or another, and for
supplying pressure oil to the steering valve in place of
the main pump until the time when the vehicle body is
moved to a safe place.
Emergency steering pump consists of the gear pump,
electric motor, relief valve, and check valve.
Electric Motor Part
Gear Pump Part
Relief Valve
Check Valve
T4GB-03-12-008
T3-12-4
MEMO
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Hitachi Construction Machinery Co. Ltd
Attn: Publications, Marketing & Product Support
Fax: 81-29-831-1162
Hitachi Ref. No.
SERVICE MANUAL REVISION REQUEST FORM
NAME OF COMPANY:
MODEL:
PUBLICATION NO.:
YOUR NAME:
DATE:
FAX:
(Located at the right top corner in the cover page)
PAGE NO.:
(Located at the bottom center in the page. If two or more revisions are requested, use the comment column)
YOUR COMMENTS / SUGGESTIONS:
Attach photo or sketch if required.
If your need more space, please use another sheet.
REPLY:
(Copy this form for usage)
WORKSHOP MANUAL
SECTION 1 GENERAL INFORMATION SECTION 3 BASE MACHINE (TRAVEL
SYSTEM)
Group 1 Precautions for DisassemGroup 1 Tire
bling and Assembling
Group 2 Drive Unit
Group 2 Tightening Torque
Group 3 Axle
Group 3 Painting
Group 4 Propeller Shaft
Group 4 Bleeding Air from HydrauGroup 5 Brake Valve
lic Oil Tank
SECTION 2 BASE MACHINE (UPPER
Group 6 Charging Block
STRUCTURE)
Group 7 Steering Pilot Valve
Group 8 Steering Valve
Group 1 Cab
Group 9 Steering Cylinder
Group 2 Counterweight
SECTION 4 FRONT ATTACHMENT
Group 3 Frame
Group 4 Pump Device
Group 1 Front Attachment
Group 5 Control Valve
Group 2 Cylinder
Group 6 Pilot Valve
Group 7 Ride Control Valve
Group 8 Pilot Shutoff Valve
Group 9 Hydraulic Fan Motor
SECTION 1
GENERAL
―CONTENTS―
Group 1 Specifications
Group 3 Component Specifications
Specifications ...........................................T1-1-1
Engine......................................................T1-3-1
Engine Accessories ..................................T1-3-5
Group 2 Component Layout
Main Component Layout...........................T1-2-1
Electrical Component Layout ....................T1-2-4
Hydraulic Component ...............................T1-3-6
Electrical Component .............................T1-3-10
(Overview)
Electrical System (Cab) ............................T1-2-5
Electrical System ....................................T1-2-6
(Controller and Relays)
Electrical System (Right Console) ............T1-2-7
Electrical System (Monitor and Switchs) ...T1-2-8
Monitor Panel ...........................................T1-2-9
Engine and Fan Pump ............................T1-2-10
Pump Device and Drive Unit................... T1-2-11
Control Valve..........................................T1-2-12
Ride Control Valve
(Optional:General Specification),
Charging Block and Fan Motor ............T1-2-13
Steering Valve and Emergency Steering Pump
(Optional:General Specification) .............T1-2-14
4HAT-1-1
GENERAL / Specification
SPECIFICATIONS
M4GB-12-002
−
Type
3
3
ZW310 (EU)
ZW310 (General)
Bucket Capacity (Heaped)
m (yd )
4.2 (BOC)
4.0 (BOC)
Operating Weight
kg(lb)
23270
22290
Static Tipping Load (Full Turn)
kg(lb)
16600
15000
Rated Loading Weight
kg(lb)
7200
6400
−
OM460LA
216.0 kW/2000 rpm
(293.7 PS/2000 rpm)
OM460LA
216.0 kW/2000 rpm
(293.7 PS/2000 rpm)
A: Overall Length
mm(ft.in)
8840
8760
B: Overall Width (Bucket)
mm(ft.in)
2980
3150
C: Overall Height
mm(ft.in)
3460
3465
D: Wheel Base
mm(ft.in)
3450
3450
E: Tread
mm(ft.in)
2230
2300
F: Ground Clearance
mm(ft.in)
480
485
G: Height to Bucket Hinge Pin, Fully Raised
mm(ft.in)
4390
4395
H: Dumping Clearance 45 Degree, Full Height
mm(ft.in)
3070
3130
I:
mm(ft.in)
1240
1180
R1: Turning Radius (Centerline of Outside Tire)
mm(ft.in)
5860
5900
R2: Loader Clearance Circle, Bucket in Carry Position
mm(ft.in)
6920
6970
Maximum Travel Speed (Forward/Reverse)
km/h(mph)
35.5/35.5
34.5/34.5
Number of Travel Shift (Forward/Reverse)
−
4/4
4/4
Degree(%)
40
40
−
26.5R25
26.5R-25-16PR
Engine
Dumping Reach, 45 Degree Dump, Full Height
Articulation Angle (Left/Right)
Tire Size
T1-1-1
GENERAL / Component Layout
ELECTRIC COMPONENT LAYOUT (OVERVIEW)
Cab
(Refer to T1-2-5)
12
2
1
13
Engine and Fan Pump
(Refer to T1-2-10)
11
10
3
4
5
7
9
Pump Device
(Refer to T1-2-11)
Drive Unit
(Refer to T1-2-11)
6
8
T4HA-01-02-011
1 - Hydraulic Oil Level Switch
5-
Boost Pressure Sensor
2 - Air Filter Restriction Switch
6-
Fuel Level Sensor
3 - Reverse Buzzer
7-
Hydraulic Oil Temperature
Sensor
8 - Emergency Steering Pump
Delivery Pressure Switch
9 - Lift Arm Angle Sensor
(Optional: General Specification)
10 - Bucket Proximity Switch
4 - Battery
T1-2-4
11 - Lift Arm Proximity Switch
12 - Implement Pressure Sensor
13 - Out Side Temperature
Sensor
GENERAL / Component Layout
Right Console
T4GB-01-02-006
2
3
4
6
5
7
1
8
9
10
18
17
16
15
14
13
12
T4GB-01-02-023
11
1 - Down Shift Switch
2 - Bucket Operation Lever
3 - Lift Arm Control Lever
4 - Forward/Reverse Switch
5 - Hone Switch
6 - Auxiliary Control Lever (Optional)
7 - Quick Coupler Switch (Optional)
8 - Lift Arm Auto Leveler Downward
Set Switch (Optional)
9 - Lift Arm Auto Leveler Upward
Set Switch (Optional)
11 - Emergency Steering Check
Switch
12 - Fan Reverse Switch
13 - Fog Light Switch (Optional:
General Specification)
14 - Ride Control Switch (Optional: General Specification)
10 - Front Control Lock Lever
T1-2-7
15 - Forward/Reverse Selector
Switch
16 - Cigar Lighter
17 - Up-shift/Down-shift Switch
18 - Hold Switch
GENERAL / Component Layout
Monitor Panel
1
2
3
4
5
6
7
8
9
10
11
34
12
33
13
14
32
15
31
T4GB-01-02-001
30
29
28
1 - Coolant Temperature
Gauge
2 - Transmission Oil Temperature Gauge
3 - Turn Signal Indicator
(Left)
4 - High Beam Indicator
5 - Working Light Indicator
6 - Turn Signal Indicator
(Right)
7 - Monitor Display
8 - Stop Indicator
9 - Service Indicator
27
26
25
24 23
22
10 - Parking Brake Indicator
21
20
19
18
11 - Clearance Light Indicator
19 - Lever Steering Indicator (Optional)
20 - Monitor Mode Selector
12 - Fuel Gauge
21 - Glow Signal
13 - Brake Low Oil Pressure
Indicator
14 - Brake Low Oil Level Indicator
15 - Emergency Steering Indicator (Optional: General
Specification)
16 - Low Steering Oil Pressure
Indicator
17 - Seat Belt Indicator
22 - Monitor Display Selector (Up)
23 - Maintenance Indicator
24 - Monitor Display selector
(Down)
25 - Forward/Reverse Switch Indicator
26 - Water Separator Indicator
18 - Discharge Warning Indicator
T1-2-9
17
16
27 - Engine Warning Indicator
28 - Overheat Indicator
29 - Engine Low Oil Pressure
Indicator
30 - Air Filter Restriction Indicator
31 - Transmission Warning Indicator
32 - Transmission Oil Filter Restriction Indicator
33 - Hydraulic Oil Temperature
Indicator
34 - Transmission Oil Temperature Indicator
GENERAL / Component Layout
PUMP DEVICE
1
2
3
6
5
T4GB-01-02-009
4
DRIVE UNIT
7
21
8
9
13
14
15
16
17
18
20
12
19
11
10
T4GC-01-02-001
1 - Main Pump
7-
2 - Regulator
Torque Converter Input
Speed Sensor
8 - Air Breather
3 - Priority Valve
9-
4 - Pump Delivery Pressure
Sensor
5 - Pilot Pump
10 - Vehicle Speed
Sensor
11 - Transmission Output
Speed Sensor
Charge Pump
12 - Transmission Middle Shaft
Sensor
13 - Forward Clutch Solenoid
Valve
14 - Reverse Clutch Solenoid
Valve
15 - 1st Clutch Solenoid Valve
16 - 2nd Clutch Solenoid Valve
6 - Steering Relief Valve
T1-2-11
17 - 3rd Clutch Solenoid Valve
18 - 4th Clutch Solenoid Valve
19 - Transmission Control Valve
20 - Parking Brake Pressure
Switch
21 - Regulator Valve
GENERAL / Component Layout
RIDE CONTROL VALVE
GENERAL SPECIFICATION)
1
2
(OPTIONAL:
CHARGING BLOCK
3
4
5
6
10
9
8
7
T4GB-01-02-013
T4GB-01-02-014
FAN MOTOR
10
11
12
T4GB-01-02-012
1 - Overload Relief Valve
2 - Ride Control Solenoid
Valve
3 - Ride Control Accumulator
5 - Service Brake Accumulator
(Front)
6 - Service Brake Accumulator
(Rear)
7 - Relief Valve
89-
Pilot Relief Valve
Pump Torque Control Solenoid Valve
10 - Parking Brake Solenoid
Valve
4 - Pilot Accumulator
T1-2-13
11 - Reverse Control Solenoid
Valve
12 - Relief Valve
13 - Flow Control Solenoid
Valve
GENERAL / Component Layout
STEERING VALVE
1
2
T4GB-01-02-020
EMERGENCY STEERING PUMP
(OPTIONAL: GENERAL SPECIFICATION)
3
4
5
6
T4GB-01-02-010
1 - Overload Relief Valve
2 - Overload Relief Valve
3 - Electric Motor
4 - Gear Pump
5 - Check Valve
T1-2-14
6-
Relief Valve
GENERAL / Component Specifications
HYDRAULIC COMPONENT
MAIN PUMP
Type.......................................................... Bent Axis Type Variable Displacement Axial Plunger Pump
Maximum Flow (Theoretical Value) .......... 340 L/min (80 US gum)
REGULATOR
Type.......................................................... Hydraulic Pressure Operated Type
PRIORITY VALVE
2
Relief Set Pressure .................................. 29.4 MPa (300 kgf/cm ) @ 90 L/min (23.8 US gpm) (ZW250)
PILOT PUMP
Model........................................................ HY/ZFS11/16.8
Type.......................................................... Fixed Displacement Type Gear Pump
Maximum Flow (Theoretical Value) .......... 33 L/min (8.7 US gpm)
CONTROL VALVE
Type.......................................................... Pilot Pressure Operated Type (2 Spools)
2
Main Relief Set Pressure.......................... 29.4 MPa (300 kgf/cm ) @ 290 L/min (77 US gpm)
2
Overload Relief Set Pressure................... 36.8 MPa (375 kgf/cm ) @ 50 L/min (13 US gpm)
(Lift Arm)
2
32.5 MPa (330 kgf/cm ) @ 50 L/min (13 US gpm)
(Bucket Tilt, Bucket Dump)
RIDE CONTROL VALVE (OPTIONAL: GENERAL SPECIFICATION)
Type.......................................................... Pilot Pressure Operated Type
2
Overload Relief Set Pressure................... 39.2 MPa (400 kgf/cm ) @ 50 L/min (13 US gpm)
2
Charge Cut Pressure................................ 11.3 MPa (115 kgf/cm )
RIDE CONTROL ACCUMULATOR (OPTIONAL: GENERAL SPECIFICATION)
3
Capacity.................................................... 5 L (305 in )
2
Charging Pressure ................................... 2.9 MPa (30 kgf/cm )
T1-3-6
GENERAL / Component Specifications
ILLUMINATION
(General Specification)
Work Light ................................................ : Halogen 24 V, 55/70 W
Cab Light .................................................. : 24 V, 10 W
Head Light ................................................ : Halogen 24 V、75/70 W
Turn Signal Light ...................................... : Front : 24 V, 25 W
:Rear : 24 V, 21 W
Clearance Light ........................................ : 24 V, 5 W
License Light ............................................ : 24 V, 12 W
Reverse Light ........................................... : 24 V, 21 W
Tail Light ................................................... : 24 V, 5 W
Brake Light ............................................... : 24 V, 21 W
(EU Specification)
Work Light ................................................ : Halogen 24 V, 70 W
Cab Light .................................................. : 24 V, 10 W
Head Light ................................................ : Halogen 24 V、75/70 W
Turn Signal Light ...................................... : 24 V, 21 W
Clearance Light ........................................ : 24 V, 4 W
License Light ............................................ : 24 V, 10 W × 2 pcs
Tail Light ................................................... : 24 V, 10 W
Brake Light ............................................... : 24 V, 21 W
AIR CONDITIONER
Refrigerant................................................ 134a
Cooling Ability........................................... 4.65 kW (16.74 MJ, 3999 kcal) or more
3
Cool Air Volume........................................ 550 m /h or more
Heating Ability........................................... 5.81 kW (20.92 MJ, 4997 kcal) or more
3
Warm Air Volume...................................... 400 m /h or more
Temperature Adjusting System ................ Electronic Type
Refrigerant Quantity ................................. 1000±50 g
3
Compressor Oil Quantity .......................... 160 cm
EMERGENCY STEERING PUMP UNIT
Type.......................................................... Electric Motor Operated Type
2
Maximum Flow ......................................... 17 L/min (4.49 gpm) @10.3 MPa (105 kgf/cm )
ELECTRIC MOTOR
Voltage...................................................... 24 V, 2.4 kW
T1-3-11
SECTION 2
SYSTEM
—CONTENTS—
Group 1 Control System
Group 4 Electrical System
Outline .....................................................T2-1-1
Outline .....................................................T2-4-1
Engine Control .........................................T2-1-6
Main Circuit ..............................................T2-4-2
Pump Control .........................................T2-1-15
Electric Power Circuit ...............................T2-4-3
Transmission Control .............................T2-1-20
Indicator Light Check Circuit.....................T2-4-4
Other Controls........................................T2-1-41
Accessory Circuit......................................T2-4-5
Control by Electric and Hydraulic
Preheat Circuit .........................................T2-4-6
Combined Circuit ..................................T2-1-51
Starting Circuit..........................................T2-4-8
Charging Circuit .....................................T2-4-12
Group 2 ECM System
Serge Voltage Prevention Circuit ............T2-4-14
Outline .....................................................T2-2-1
Engine Stop Circuit .................................T2-4-16
Fuel Injection Control ...............................T2-2-2
Lamplight Circait ....................................T2-4-17
Head Light Circuit...................................T2-4-18
Group 3 Hydraulic System
Outline .....................................................T2-3-1
Turn Signal Circuit ..................................T2-4-22
Main Circuit ..............................................T2-3-2
Brake Light Circuit ..................................T2-4-23
Pilot Circuit.............................................T2-3-13
Hazard Light Circuit ................................T2-4-24
Steering Circuit.......................................T2-3-26
Horn Circuit ............................................T2-4-25
Hydraulic Drive Fan Circuit .....................T2-3-32
Reverse Light/Buzzer Circuit ..................T2-4-26
Parking Brake Circuit..............................T2-4-28
Emergency Steering Check Circuit
(Optional : General Specification) .........T2-4-30
4HAT-2-1
SYSTEM / Control System
Sensors and switches to detect signals for various
operation controls and their controllers are as shown
below.
Input Signals
• Accelerator Pedal Sensor
• Driving Mode Switch
Output Signals
Engine Control
→
→
→Accelerator Pedal Control
• Work Mode Selector Switch
→
• Fan Reverse Switch
→
• Ride Control Switch (OP: General Spec.) →
• Parking Brake Pressure Sensor
→
• Pump Delivery Pressure Sensor
→
• Imprement Pressure Sensor
→
• Hydraulic Oil Temperature sensor
→
• Clutch Cut Position Sensor
→
• Lift Arm Kick-out Switch
→
• Lift Arm Angle Sensor (OP)
→
• Lift Arm Auto-leveler Upwards
Set Switch (OP)
→
• Lift Arm Auto-leveler Downwards
Set Switch (OP)
→
•
MC
→Automatic Warming Up Control
→Engine Speed Reduction Control
Pump Control
→Standard Torque Control
→Torque Reduction Control
Other Controls
→Hydraulic Fan Cooling Control
→Hydraulic Fan Cleaning Control
→Transmission Alarm Control
→Forward/Reverse Indicator Control
→Reverse Traveling Alarm Control
→Parking Brake Alarm Control
CAN
(See next chart)
NOTE: OP : Stands for optional.
* : Controls for optional parts provision
machines only
T2-1-4
Control by Electric and Hydraulic
Combined Circuit
→*Ride Control
Bucket Auto-leveler Control
Lift Arm Float Control
→Lift Arm Kick-out Control
→*Lift Arm Auto-leveler Upward Control
→*Lift Arm Auto-leveler Downward Control
SYSTEM / Control System
Engine Control System Layout
Work Mode
Selector Switch
L
Accelerator Pedal
Hydraulic Oil
Temperature
Sensor
Accelerator Pedal Sensor
N
P
Main Pump Delivery
Pressure Sensor
Shift Switch
ECM2
MC
Transmission
ECM1
Engine
Torque Converter Output
Speed Sensor
Torque Converter Input
Speed Sensor
Monitor
Unit
Engine Coolant
Temperature Sensor
T2-1-7
T4HA-02-01-002
SYSTEM / Control System
Engine Speed Reduction Control
Purpose: Reducing fuel consumption and improving
fuel consumption rate by lowering engine
speed in case traveling digging has been
made to the extent the engine almost stalls
Engine
Actual
Speed
Power Mode (P)
Maximum
Speed
Normal Mode (P)
Operation:
1. When signal of the selected work mode is
transmitted to the MC, it starts the engine speed
reduction program corresponding to the selected
work mode.
• When power mode (P) is selected, engine speed
reduction control is not made, which is
advantageous in making much of production.
• When normal mode (N) is selected, engine speed
is reduced to the speed within the set range,
which is advantageous in making much of
production as well as low fuel consumption.
• When light mode (L) is selected, engine is
reversed at the maximum speed within the range
larger than that for normal mode (N), which is
advantageous in making much of low fuel
consumption.
Light Mode (L)
Minimum
Speed
2. When traveling digging is started, MC detects
signals from the accelerator pedal sensor, pump
delivery pressure sensor, and torque converter
output speed sensor, and transmits the target
engine speed to the ECM1 by figuring out the
most suitable engine speed reduction in response
to the traveling digging load applied to the body.
3. In traveling digging, the larger the load applied to
the body is, the larger the engine speed reduction
is.
4. ECM1 transmits the target engine speed
command value to the ECM2, and reduces the
engine speed to the target speed.
NOTE: In case signal from the work mode selector
switch is not transmitted to the MC,
back-up control of fixing the work mode to
normal is made.
NOTE: In case either of the accelerator pedal
sensor, main pump delivery pressure
sensor, or torque converter input speed
sensor becomes abnormal, engine speed
reduction control is not made.
T2-1-12
Minimum
Speed
Maximum
Speed
Target
Engine Speed
Conceptual Diagram of
Maximum Speed Reduction Control
NOTE: Shift switch has two switches, and their
combination of ON varies depending on
each speed shift. Controller judges which
speed shift has been selected by the
combination of the two input signals.
NOTE: Each mode switch of the work mode
selector switch is supplied with respectively
different voltages from the monitor unit, and
when the switch selects a mode, the MC
judges which mode has been selected by
the input voltage.
SYSTEM / Control System
Work Mode
Selector Switch
Accelerator Pedal
L
Accelerator Pedal Sensor
N
P
Main Pump Delivery
Pressure Sensor
Shift Switch
ECM2
MC
Transmission
ECM1
Engine
Torque Converter
Output Speed Sensor
Torque Converter
Input Speed Sensor
Monitor
Unit
T4HA-02-01-005
NOTE: Illustration shows flow of the signal in case
normal mode (N) of the work mode selector
switch and Speed 1 of the shift switch have
been selected.
If traveling digging is thus continued until
traveling is stopped, the engine maximum
speed is reduced to the maximum reduced
speed when normal mode is selected.
T2-1-13
SYSTEM / Control System
PUMP CONTROL
Following pump controls are made.
• Standard Torque Control
• Torque Reduction Control
Pump Control System Layout
Accelerator Pedal
Accelerator Pedal Sensor
Main Pump Delivery
Pressure Sensor
ECM2
MC
Transmission
ECM1
Engine
Main Pump
regulator
Pump Torque Control
Solenoid Valve
Torque Converter
Output Speed Sensor
Monitor
Unit
Torque Converter
Input Speed Sensor
T4HA-02-01-006
T2-1-15
SYSTEM / Control System
Torque Reduction Control
Purpose: Effectively utilizing engine horsepower by
changing pump flow in response to increase
or decrease of the engine speed due to
traveling load
Operation:
1. When accelerator pedal is stepped, MC makes
arithmetic operation of the target engine speed.
Q
Flow
2. MC makes arithmetic operation, using the target
engine speed and signals from the main pump
delivery pressure switch, torque converter input
speed sensor, and torque converter output speed
sensor, and figures out the pump maximum tilting
angle most suitable to each time to transmit it to
the pump torque control solenoid valve.
P-Q Line
3. Pump torque control solenoid valve transmits pilot
pressure corresponding to the amplitude of signal
to the main pump regulator, and controls the
pump flow rate.
4. If load applied to the engine becomes large and
decreases the actual engine speed than the
target speed, the pump tilting angle is decreased
to reduce delivery flow. Thus, maneuverability of
the vehicle body is improved.
5. MC makes arithmetic operation of the actual
engine speed, receiving signal from the torque
converter input speed sensor.
Pressure
P
NOTE: In case the accelerator pedal becomes
abnormal, the back-up control of the
accelerator controls and fixes the engine
-1
speed at 1000 min .
NOTE: In case signal from either the main pump
delivery pressure sensor, torque converter
input speed sensor, or torque converter
output speed sensor is not transmitted to
the MC, it does not make torque reduction
control, but makes pump control by the
standard-torque control.
NOTE: In case the pump torque control solenoid
valve
becomes
abnormal,
neither
standard-torque
control
nor
torque
reduction control is made.
T2-1-18
SYSTEM / Control System
Accelerator Pedal
Accelerator Pedal Switch
Main Pump Delivery
Pressure Sensor
ECM2
MC
Transmission
ECM1
Engine
Main Pump
Regulator
Pump Torque Control
Solenoid Valve
Torque Converter
Output Speed Sensor
Monitor
Unit
Torque Converter
Input Speed Sensor
T4HA-02-01-008
T2-1-19
SYSTEM / Control System
CONTROL BY ELECTRIC AND
HYDRAULIC COMBINED CIRCUIT
Electric and hydraulic combined circuit has the
following controls.
• Ride control (Optional: General Specification)
• Bucket positioner control
• Lift arm float control
• Lift arm kick-out control
• Lift arm auto-leveler upward control
(Optional)
• Lift arm auto-leveler downward control
(Optional)
T2-1-51
SYSTEM / Control System
Ride Control (Optional: General Specification)
Purpose: Reducing fatigue of the operator by
organizing a damper circuit in the lift arm
cylinder and reducing shock in traveling on
rough roads
Operation:
1. When the ride control switch is turned ON, the MC
makes the ride control effective, and the ride
control indicator of the monitor is lit.
2. At vehicle speed of 7 km/h (4 mph) and above, the
MC receives signal from the vehicle speed sensor,
and transmits electric current to the ride control
solenoid valve.
3. When the ride control solenoid valve is operated
and the spool moves, a damper circuit is
organized between the rod end and the bottom
end of the lift arm cylinder. When the vehicle body
travels on bumpy roads, the fluctuation of the
bottom pressure of the lift arm cylinder is
absorbed by the ride control accumulator, and the
shock of the whole vehicle body is reduced.
NOTE: Ride control is not made at the vehicle
speed of 7 km/h (4 mph) and below.
NOTE: In case the ride control switch or the ride
control solenoid valve becomes out of order,
the ride control is not made.
T2-1-52
SYSTEM/Hydraulic System
PILOT CIRCUIT
Outline:
Pressure oil from the pilot pump is used to operate the
circuit below.
• Charging Block Circuit
• Front Attachment Operation Control Circuit
• Pump Control Circuit
• Brake Circuit
• Ride Control Circuit
(Optional:
General
Specification)
Front Attachment
Control Circuit
Pilot Shutoff
Valve
Lift Arm Pilot
Valve
Bucket Pilot
Valve
Optional Pilot
Valve
Control Valve
Brake
Valve
Service
Brake
Brake Circuit
Parking
Brake
Charging Block
Main Pump
Regulator
Pump Control Circuit
Spool
Ride Control Circuit
(Optional: General
Specification)
Ride
Control
Solenoid
Valve
Ride Control Valve
Charging Block Circuit
Pilot
Filter
Pilot
Pump
Suction
Filter
Hydraulic
Oil
Tank
T4GC-02-02-001
T2-3-13
SYSTEM/Hydraulic System
Service Brake
Brake
Valve
Front Brake
Service Brake
Accumulators
Brake
Valve
Rear Brake
Check
Valves
Relief Valve
B
Priority
Valve
A
Spring
Charging Block
Pilot Pump
NOTE: Illustration shows oil flow when the priority
valve is closed in response to pressure
decrease in the service brake circuit.
T2-3-15
T4GC-02-02-002
SYSTEM/Hydraulic System
Bucket
Pilot Valve
Lift Arm
Pilot Valve
Spare Pilot
Valve (Optional)
Pilot Shutoff Valve
To Service Brake
Circuit
Service Brake
Accumulators
Priority Valve
Relief Valve
B
Pilot Pump
Pilot
Relief Valve
Hydraulic Oil Tank
PS1
PS2
X
Parking Brake
Pressure Sensor
BR3
A
Spring
Pump Torque Control
Solenoid Valve
Parking Brake
Solenoid Valve
PP
Charging Block
NOTE: Illustration shows the oil flow in neutral
condition of the pilot valve when the service
brake accumulators are pressurized, the
priority valve is open, and the pilot shutoff
valve is open.
T2-3-17
T4GB-02-02-020
SYSTEM/Hydraulic System
Bucket
Pilot Valve
Lift Arm
Pilot Valve
1
3
2
4
Spare Pilot
Valve (Optional)
5
6
7
8
Control Valve
Pilot Shutoff Valve
8
Spare 2
7
To Service Brake
Circuit
Service Brake
Accumulators
6
Priority Valve
2
Spare 1
5
Bucket
1
Pilot Pump
4
Slow-Return
Valves
Lift Arm
3
Main Pump
PP
Charging Block
T4GB-02-02-021
NOTE: Numeral of each port of the pilot valves and
the control valve shows the port to be
connected.
Illustration shows the oil flow in neutral
condition of the pilot valve when the service
brake accumulators are pressurized, the
priority valve is open, and the pilot shutoff
valve is open.
T2-3-19
SYSTEM/Hydraulic System
Charging Block
Pilot Pump
Pump Torque Control
Solenoid Valve
Hydraulic Oil Tank
PS2
Command Signal from MC
Pilot Presser (X)
Orifice
Pump From Control Valve
Control Valve
Pi2
Pi1
Main Pump
Main Pump
Regulator
Servo
Piston
T4HA-02-03-003
T2-3-21
SYSTEM/Hydraulic System
Service Brake
Brake
Pedal
Front Brake
Service Brake
Accumulators
Brake
Valve
Rear Brake
Check
Valves
Relief Valve
Priority
Valve
Spring
Parking Brake
Pressure Sensor
Parking
Brake
Solenoid
Valve
Parking Brake
Release
Pilot
Accumulator
No Signal for
Parking Brake
Release
Brake
Charging Block
Pilot Pump
NOTE: Illustration shows oil flow when the relief
valve and the priority valve are open in
response to pressure increase in the
service brake circuit, and also oil flow when
the parking brake is working with the
unexcitement of the parking brake solenoid
valve.
T2-3-23
T4GC-02-02-003
SYSTEM/Hydraulic System
Ride
Control
Circuit
(Optional:
General
Specification)
(Refer to SYSTEM / Electric-Hydraulic Combined
Circuit Control in Control System)
• In front attachment operation, operating pressure
from the lift arm cylinders is accumulated in the
ride control accumulator through the charge cut
spool.
• When the ride control switch is turned ON, the
ride control solenoid valve is excited, and the
spool moves downward.
• Bottom end of the lift arm cylinders is connected
with the ride control accumulator, while the rods
side end of the lift arm cylinders is connected to
the hydraulic oil tank.
• In this way, force to raise the front attachment is
relieved to the hydraulic oil tank, and force to
lower the front attachment is absorbed by the ride
control accumulator, thus enabling stable
traveling on rough roads.
T2-3-24
SYSTEM/Hydraulic System
Steering Shock Damping Circuit
• Pressure of the pressure oil supplied from the
steering pilot valve to the spool end of the
steering valve is reduced by passing through the
orifice inside the steering valve, and is applied to
the spool end of the opposite side. In this way, the
vehicle shock due to sudden shift of the spool is
damped, and stable steering operation is possible.
(Refer to COMPONENT OPERATION / Steering
Valve)
• Steering accumulators are provided for damping
the joggling of the vehicle taking place at stop of
the steering wheel rotation.
Emergency Steering Circuit (Optional: General
Specification)
• When traveling, if the main pump delivery is
stopped or drastically decreased caused by
failure of the engine or the main pump, the signal
of the pump delivery pressure swithc is
transmitted into the monitor controller, and the
monitor controller starts the motor of the
emergency steering pump equipment.
• Pressure oil is supplied from the emergency
steering pump for 1 minute, and steering
operation is possible.
• When 1 minute have passed or when the key
switch has been turned OFF after moving the
vehicle to a safe place, the emergency steering
pump stops.
NOTE: When engine is started, the monitor unit
automatically
starts
the
emergency
steering pump unit to confirm its function.
When the pressure sensing signal of the
emergency
steering
pump
delivery
pressure switch enters the monitor unit, the
emergency
steering
pump
unit
automatically stops. (EU Model Only)
T2-3-28
SYSTEM/Electric System
Key Switch
From #163Terminal
of Fuse Box A
From #6 terminal
of Fuse Box B
684
Monitor Unit
119
From Terminal L
of Alternator
(When forming a self-exciting circuit)
ON
NEUTRAL
Parking Brake
Switch
イ
Parking Brake Parking Brake
Relay 2
Relay 1
OFF
AB
E F GH
A B CD E
A B CD E
684
Monitor Unit
119
To #638 Terminal
of Fuse Box B
Fuse
(100A)
Battery
Relay
Fuse Box A
264
362
692
210
124
135
867
55
163
693
108
12
144
133
121
696
695
698
699
700
157
123
54
79
99
120
694
697
Battery
Parking Brake
Solenoid Valve
From Terminal L
of Alternator
T4GB-02-03-016
NOTE: Illustration shows flow of electric current
when the parking brake switch remains
pushed after the parking brake switch has
been turned OFF during rotation of the
engine.
T2-4-29
SYSTEM/Electric System
EMERGENCY STEERING CHECK CIRCUIT
(OPTIONAL: GENERAL SPECIFICATION)
(Manual Check Circuit)
• When the key switch is turned ON, the electric
current from Terminal M the battery relay, and the
electricity from the power source enters the
emergency steering relay through #323 terminal
of Fuse Box B, and also enters Terminal B of the
emergency steering pump unit.
• When the emergency steering check switch is
turned ON, electric current flows to #179 Terminal
of the monitor unit.
• At the same time, as the monitor unit excites #180
Terminal, the emergency steering relay is excited.
• Electricity from the power unit enters Terminal C
of the emergency steering pump unit through the
emergency steering relay, exciting Terminal B,
and the emergency steering pump unit is started.
IMPORTANT: Emergency steering pump unit is
not so designed as to be operated
for a long time. When its operation
has been confirmed, turn the
emergency steering check switch
OFF by stopping pushing the switch.
(Auto Check Circuit)(EU Model Only)
• When the engine is started by turning the key
switch to the ST position, the alternator starts
generating electricity.
• When part of the electricity generation signal from
Terminal L of the alternator enters the monitor unit,
and rises to the predetermined voltage, Terminal
#180 is earthed, and the emergency steering
relay is excited.
• Electricity from the power unit enters Terminal C
of the emergency steering pump unit through the
emergency steering relay, exciting Terminal B,
and the emergency steering pump unit is started.
• The emergency steering pump unit works for
several seconds, and then the earthed circuit of
Terminal #180 is automatically cancelled and the
emergency steering pump unit stops.
• In case hydraulic oil higher than the
predetermined value has been being delivered
during operation of the emergency steering pump
unit, the emergency steering pump delivery
pressure switch is turned OFF, and the automatic
inspection operation is stopped normally.
• In case hydraulic oil higher than the
predetermined value has not been being
delivered, the emergency steering pump delivery
pressure switch remains ON, and the emergency
steering operation warning lamp on the monitor
unit flickers to notify abnormality of the
emergency steering pump unit.
T2-4-30
Group 7 Charging Block
Group 11 Brake Valve
Outline .....................................................T3-7-1
Outline ................................................... T3-11-1
Priority Valve ............................................T3-7-6
Operation ............................................... T3-11-4
Pilot Relief Valve ......................................T3-7-7
Pump Torque Control Proportional
Group 12 Others
Solenoid Valve .......................................T3-7-8
Pilot Shutoff Valve ..................................T3-12-1
Service Brake Accumulator,
Propeller Shaft .......................................T3-12-2
Pilot Accumulator ...................................T3-7-9
Emergency Steering Check Block ...........T3-12-3
Parking Brake Solenoid Valve ................T3-7-10
Emergency Steering Pump
Service Brake Pressure Sensor..............T3-7-12
(Optional: General Specification) ............T3-12-4
Parking Brake Pressure Sensor .............T3-7-12
Group 8 Ride Control Valve
Outline .....................................................T3-8-1
Operation .................................................T3-8-4
Charge Cut Spool .....................................T3-8-6
Over Load Relief Valve .............................T3-8-8
Ride Control Accumlator .........................T3-8-10
Drain Plug .............................................. T3-8-11
Group 9 Drive Unit
Outline .....................................................T3-9-1
Torque Converter .....................................T3-9-2
Transmission............................................T3-9-4
Transmisson Regulator Valve .................T3-9-26
Transmission Control Valve ....................T3-9-28
Manual Spool (Emergency Travel
Spool ....................................................T3-9-36
Proportional Solenoid Valve....................T3-9-38
Group 10 Axle
Outline ...................................................T3-10-1
Differential..............................................T3-10-2
Torque Proportioning Differential (TPD) ..T3-10-6
Limited Slip Differential (LSD) ................T3-10-8
Service Brake....................................... T3-10-10
Final Drivel Axle Shaft .......................... T3-10-12
4HAT-3-2
COMPONENT OPERATION / Pump Device
OUTLINE
Pump device has a main pump (1) and a pilot pump (2),
and main pump (1) has a built-in priority valve (6).
Driving force of the engine is transmitted to the shaft
(3) through the transmission input shaft, and actuates
main pump (1) and pilot pump (2).
Main pump (1) is a swash-plate type variable
displacement axial plunger pump.
Pilot pump (2) is a gear pump.
Pump delivery pressure sensor (4) is provided for
controlling the main pump.
1
2
5
6
3
4
T4GB-03-01-001
1 - Main Pump
3 - Shaft
5-
2 - Pilot Pump
4 - Pump Delivery Pressure
Switch
6-
T3-1-1
Steering Main Relief
Valve
Priority Valve
COMPONENT OPERATION / Pump Device
Pump
Control
Pressure Pi1
Pilot
To Hydraulic
Primary
Oil Tank
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
11
10
T4GB-03-01-008
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-009
T3-1-9
COMPONENT OPERATION / Pump Device
Pump
Control Pressure
Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-010
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
3
2
4
1
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-011
T3-1-11
COMPONENT OPERATION / Pump Device
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
13
Self Delivery
Pressure Pd1
9
12
10
11
T4GB-03-01-014
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
Self Delivery
Pressure Pd1
13
12
10
11
T4GB-03-01-015
T3-1-15
COMPONENT OPERATION / Pump Device
5
Pump
Control
Pressure Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
9
13
Self Delivery
Pressure Pd1
12
10
11
T4GB-03-01-016
5
Pump
Control Pressure
Pi1
To Hydraulic
Oil Tank
Pilot
Primary
Pressure Pg
6
7
Pump
Control Pressure
Pi2
Pump Torque
Control Pressure
ST
8
13
Self Delivery
Pressure Pd1
9
12
10
11
T4GB-03-01-017
T3-1-17
COMPONENT OPERATION / Pump Device
PILOT PUMP
Drive gear (1) is driven throught the shaft of the main
pump, and the diven gear (2) geared to this also
rotates.
1 - Drive Gear
Suction Port
1
2
2 - Driven Gear
Delivery Port
T137-02-03-005
PUMP DELIVERY PRESSURE SENSOR
Pump delivery pressure necessary for various kinds of
control is sensed. Hydraulic pressure is received by
the diaphragm (9), and deformation of the diaphragm
is sensed as an electric signal.
6 - Earth
7 - Output
8 - Electric Source (5V)
9 - Pressure-applied Part
(Diaphragm)
6
T3-1-19
7
8
9
T157-02-03-010
COMPONENT OPERATION/Control Valve
Bucket Cylinder
Lift Arm
Cylinder
Control Valve
Overload
Relief Valve
Bucket
Lift Arm
Parallel Circuit
Main Relief Valve
Main Pump
T4GB-03-02-023
T3-2-9
COMPONENT OPERATION / Hydraulic Fan Motor
REVERSE CONTROL VALVE
Fan motor is reversed by operations of the reverse
control solenoid valve and the reverse spool.
Operation
• At Neutral of Reverse Control Solenoid Valve
1. When reverse control solenoid valve (1) is at
neutral, the pressure oil (P) from the fan pump is
blocked by changeover valve (2).
2. As reverse spool (3) is being pushed by spring (4),
the pressure oil (P) from the fan pump flows to
port MB, and the fan motor rotates normally.
• In Operation of Reverse Control Solenoid Valve
1. When reverse control solenoid valve (1) is
operated, the pressure oil from the fan pump
flows to the right end of reverse spool (3) through
changeover valve (2).
2. When the pressure oil entering the right end of
reverse spool (3) overcomes the spring (4),
reverse spool (3) moves leftwards.
3. Pressure oil (P) from the fan pump flows to port
MA, and the fan motor makes reverse rotation.
T3-3-8
COMPONENT OPERATION / Steering Pilot Valve
OPERATION
4
Sleeve (3), spool (4), and drive (7) are mutually
connected by pin (5). When the handle (or the spool
(4)) is turned, a relative angular difference arises
between sleeve (3) and spool (4) because the hole of
spool (4) is a lengthened one.
Movement of the steering handle is conveyed only to
spool (4), and port P (from the steering pump) is
connected to port R (to the steering valve) or port L
through sleeve (3) and spool (4).
8
3
Port L
2
Port R
Handle
Port T
Port P
7
11
7
T4GB-03-04-007
11
1
6
10
9
2
T1F3-03-07-002
1
5
4
3
T3-4-3
7
8
COMPONENT OPERATION / Pilot Valve
Pusher Stroke: between A and B
1
2
3
4
5
6
Port T
(Clearance of
Part A: 0)
（A）
Port P
Notch Part
7
Output Port
1 - Lever
2 - Push Rod
3 - Pusher
4 - Spring Guide
T4GB-03-05-004
T4GB-03-05-003
5 - Balance Spring
6 - Return Spring
T3-6-3
7-
Spool
COMPONENT OPERATION / Pilot Valve
Pusher Stroke: between C and D
Pusher Stroke: between E and F
3
5
(C)
Port T
4
Notch Part
Face B
Port P
Port P
7
7
Output Port
3-
Pusher
4-
Spring Guide
Output Port
T4GB-03-05-005
5-
T3-6-5
Balance Spring
7-
Spool
T4GB-03-05-006
COMPONENT OPERATION / Drive Unit
Side View of Transmission
3
2
1
4
5
3
6
7
10
8
9
11
T4GC-03-09-005
1 - Converter Inlet Pressure
Port
2 - Regulator Valve
3 - Regulator Pressure Port
4-
Forward Clutch Pressure
Port
5 - Reverse Clutch Pressure
Port
6 - 1st Speed Clutch Pressure
Port
7-
2nd Speed Clutch Pressure
Port
8 - 3rd Speed Clutch Pressure
Port
9 - 4th Speed Clutch Pressure
Port
T3-9-7
10 - Parking Brake Release
Pressure Inlet
11 - Parking Brake Pressure
Switch Port
COMPONENT OPERATION / Drive Unit
Forward 3rd Speed
Furthermore, torque is outputted from 3rd hub gear
(13) to high-range gear (14), and eventually
outputted to output gear (15).
In the case of forward 3rd speed, the forward clutch
and the speed 3 part of the 3rd & 4th Speeds clutch
are connected. Torque converter transmits torque to
F hub gear (4) geared to the input gear (1).
Torque from F hub gear (4) is transmitted to 3rd
Speed hub gear (13) through F - R gear (3) and idler
gear (8).
1
Input
4
Forward
Clutch
3
7
3rd & 4th
Speed clutch
8
13
14
15
Output
Power Flow: Forward 3rd Speed
T3-9-20
T4GC-03-09-019
COMPONENT OPERATION / Axle
Traveling Straight with the Same Road Resistances to Left and Right Tires
As the differential pinion gear and the left and right
pinion gears rotate solidly, the drive forces of the left
and right tires are the same similarly to the TPD.
Traveling on Soft Roads (Different Road Resistances to Left and Right Tires)
Drive force is transmitted to the case, pressure ring,
and spider through the ring gear. At this time, the
spider having the cam construction pushes the
pressure ring with the thrust P. Clutch disc is geared
with the case through the pressure ring. Side gears
fitted to the clutch disc by spline rotate solidly with the
case, and the left and right gears rotate at the same
speed.
Like this, the left and right axle shafts fitted to the
side gears by spline tend to rotate solidly with the
case, and the differential movement restriction works.
In case the drive force provided for the skidding tire
is larger than the road resistance, part of the torque
of the skidding tire is added to the tire contacting the
road by the differential movement restriction (because of the same speed of the left and right tires),
and the tire contacting the road is provided with more
torque.
Until the difference of the resistances between the
left and right tires exceeds certain value (until the
clutch disc begins to slip), the left and right gears
solidly rotate at a constant speed. On such soft roads,
the drive force increases by 1.5 times the value for
the TPD if the LSD is provided.
T3-10-9
Clutch Disc
P
P
Pressure Plate
Spider
Pressure Ring
T4GB-03-10-004
Group 5 Component Test
Primary Pilot Pressure ................................. T4-5-1
Secondary Pilot Pressure ............................ T4-5-3
Solenoid Valve Set Pressure ....................... T4-5-4
Main Pump Delivery Pressure ..................... T4-5-6
Main Relief Pressure.................................... T4-5-8
Steering Relief Pressure ............................ T4-5-10
Overload Relief Valve Set Pressure .......... T4-5-12
Main Pump Flow Rate................................ T4-5-14
Regulator Adjustment................................. T4-5-18
Service Brake Pressure (Front and Rear) . T4-5-20
Parking Brake Pressure ............................. T4-5-22
Brake Accumulated Pressure .................... T4-5-24
Brake Warning Set Pressure (Decrease) .. T4-5-26
Brake Warning Set Pressure (Increase) .... T4-5-28
Transmission Clutch Pressure ................... T4-5-30
Torque Converter Pressure
(Inlet and Outlet)..................................... T4-5-31
Group 6 Adjustment
Transmission Learning................................. T4-6-1
Lift Arm Angle Sensor
Learning (Optional)................................... T4-6-6
Unit Injector Setting...................................... T4-6-8
4HAT-4-2
OPERATIONAL PERFORMANCE TEST / Introduction
OPERATIONAL PERFORMANCE TESTS
Use operational performance test procedure to quantitatively check all system and functions on the machine.
Purpose of Performance Tests
1. To comprehensively evaluate each operational
function by comparing the performance test data
with the standard values.
2. According to the evaluation results, repair, adjust,
or replace parts or components as necessary to
restore the machine’s performance to the desired
standard.
3. To economically operate the machine under optimal conditions.
The machine performance does not always deteriorate as the working hours increase. However, the
machine performance is normally considered to reduce in proportion to the increase of the operation
hours. Accordingly, restoring the machine performance by repair, adjustment, or replacement shall consider the number of the machine’s working hours.
Definition of “Performance Standard”
1. Operation speed values and dimensions of the
new machine.
2. Operational performance of new components
adjusted to specifications. Allowable errors will be
indicated as necessary.
Kinds of Tests
1. Base machine performance test is to check the
operational performance of each system such as
engine, travel, swing, and hydraulic cylinders.
2. Hydraulic component unit test is to check the operational performance of each component such
as hydraulic pump, motor, and various kinds of
valves.
Performance Standards
“Performance Standard” is shown in tables to evaluate the performance test data.
Precautions for Evaluation of Test Data
1. To evaluate not only that the test data are correct,
but also in what range the test data are.
2. Be sure to evaluate the test data based on the
machine operation hours, kinds and state of work
loads, and machine maintenance conditions.
T4-1-1
OPERATIONAL PERFORMANCE TEST / Introduction
PREPARATION
TESTS
FOR
PERFORMANCE
Observe the following rules in order to carry out
performance tests accurately and safely.
THE MACHINE
1. Repair any defects and damage found, such as
oil or water leaks, loose bolts, cracks and so on,
before starting to test.
TEST AREA
1. Select a hard and flat surface.
2. Secure enough space to allow the machine to
run straight more than 200 m (656 ft 2 in), and to
operate steering.
3. If required, rope off the test area and provide
signboards to keep unauthorized personnel
away.
PRECAUTIONS
1. Before starting to test, agree upon the signals to
be employed for communication among coworkers. Once the test is started, be sure to communicate with each other using these signals, and to
follow them without fail.
2. Operate the machine carefully and always give
first priority to safety.
3. While testing, always take care to avoid accidents due to landslides or contact with
high-voltage power lines. Always confirm that
there is sufficient space for full swings.
4. Avoid polluting the machine and the ground with
leaking oil. Use oil pans to catch escaping oil.
Pay special attention to this when removing hydraulic pipings.
MAKE PRECISE MEASUREMENT
1. Accurately calibrate test instruments in advance
to obtain correct data.
2. Carry out tests under the exact test conditions
prescribed for each test item.
3. Repeat the same test and confirm that the test
data obtained can be produced repeatedly. Use
mean values of measurements if necessary.
T4-1-2
T105-06-01-003
OPERATIONAL PERFORMANCE TEST / Standard
OPERATIONAL PERFORMANCE
STANDARD TABLE
 ZW310 EU STANDARD
The standard performance values are listed in the
table below. Refer to the Group T4-3 or later for
performance test procedures.
Acceletor Pedal
: Full Stroke
Driving Mode Switch : H Mode
Work Mode Switch : N Mode
Hydraulic Oil Temperature : 505 C (12241 F)
The following switch positions shall be selected and
the hydraulic oil temperature shall be maintained as
indicated below as the preconditions of performance
tests unless otherwise instructed in each performance
test procedure:
PERFORMANCE TEST DESIGNATION
ENGINE SPEED (FAN SPEED min/max) min-1
Slow Idle Speed (without load)
Fast Idle Speed (without load)
Fast Idle Speed (with torque converter
stalled)
Fast Idle Speed (with torque converter
stalled and relieved)
VALVE CLEARANCE (IN, EX)
mm
LUBRICANT CONSUMPTION
(Rated output)
mL/h
DRIVE BELT BEND
mm
RADIATOR CAP OPENING PRESSURE
kPa (kgf/cm2, psi)
Performance
Standard
84025
2120/211025
NOTE: 1 mm=0.03937 in
Reference
Remarks
Page
T4-3-1
Value indicated on Dr. ZX

1980/192050

1710/170050

0.4/0.6
40 or less
-
T4-2-1
With the engine cold
Hour meter: 2000 hours or
less
Auto adjustment
-
T4-3-5
T4-3-8
-
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
TRAVEL SPEED
km/h
First Gear (Forward/Reverse)
Second Gear (Forward/Reverse)
Third Gear (Forward/Reverse)
Fourth (Forward/Reverse)
SERVICE BRAKE CAPACITY
m
SERVICE BRAKE WEAR
mm
Brake Disc
Brake Ring (t=15)
Brake Ring (t=5)
PARKING BRAKE CAPACITY
mm/5 min
PARKING BRAKE WEAR
mm
Brake Disc
Brake Ring
BUCKET STOPPER CLEARANCE
mm
BELL CRANK STOPPER CLEARANCE
mm
FRONT PIN WEAR
mm
(to new pin outer diameter)
FRONT BUSHING WEAR
mm
(to new pin outer diameter)
CLEARANCE BETWEEN FRONT PIN
AND BUSHING
mm
BUCKET BUMP
mm
HYDRAULIC CYLINDER CYCLE TIME sec
Lift Arm Raise
Lift Arm Lower (Float)
Bucket Roll-Out
Steering (engine: neutral)
Steering (engine: full)
DIG FUNCTION DRIFT CHECK mm/15 min
Lift Arm Cylinder
Bucket Cylinder
Bucket Bottom
Performance
Standard
7.0/7.0±0.7
11.8/11.8±1.2
22.0/22.0±2.2
35.5/35.5±3.6
5.0 or less
Remarks
Reference
Page
T4-4-1
Value indicated on Dr. ZX
↑
↑
↑
T4-4-2
T4-4-3
6.2
15.0
5.0
0
Allowable Limit: 5.3
Allowable Limit: 13.5
Allowable Limit: 4.5
2.2
2.4
0
Allowable Limit: 1.9
Allowable Limit: 2.2
T4-4-4
-
T4-4-6
T4-4-6
2
-
Allowable Limit: -1.0
-
-
Allowable Limit: -1.5
-
0.3
14
T4-4-11
T4-4-8
5.4±0.3
3.0±0.3
1.1±0.3
2.8±0.3
2.5±0.3
T4-4-10
45 or less
15 or less
150 or less
T4-2-2
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
Performance Standard
CONTROL LEVER OPERATING FORCE
N (kgf, lbf)
Lift Arm Raise (STD/MF)
Lift Arm Raise Detent (STD/MF)
Lift Arm Raise Detent Release (STD/MF)
Lift Arm Lower (STD/MF)
Lift Arm Lower Float (STD/MF)
Lift Arm Lower Float Release (STD/MF)
Bucket Lever Tilt (STD/MF)
Bucket Lever Tilt Detent (STD/MF)
Bucket Lever Tilt Detent Release (STD/MF)
Bucket Lever Dump (STD/MF)
Steering Wheel (Right/Left)
11 (1.1, 2.5)/
19 (1.9, 4.3) or less
17 (1.7, 3.8)/
30 (3.1, 6.8) or less
40 (4.1, 9)/
20(2.0, 4.5) or less
11 (1.1, 2.5)/
19 (1.9, 4.3) or less
17 (1.7, 3.8)/
30 (3.1, 6.8) or less
40 (4.1, 9)/
20 (2.0, 4.5) or less
12 (1.2, 2.7)/
22 (2.2, 5) or less
18 (1.8, 4)/
33 (3.3, 7.4) or less
40 (4.1, 9)/
20 (2.0, 4.5) or less
17(1.7, 3.8)/
28 (2.9, 6.3) or less
17 (1.7, 3.8)/
17 (1.7, 3.8) or less
Forward/Reverse Lever
11.8+1-2
(1.2+0.1-0.2, 2.7+0.2-0.5)/
11.8+1-2
(1.2+0.1-0.2, 2.7+0.2-0.5)
Accelerator Pedal
25.0±3.5
(3. 6±0.4, 5.6±0.8)
Brake Pedal Right
318+65-45
(32.4+6.6-4.6, 71.6+14.6-10.1)
Inching Pedal Left
288+80-30 (29.4+8.2-3.1,
64.8+18-6.8)
NOTE: STD: Standard Lever (Two-Lever)
MF: Multi-Function Lever (Joystick Lever)
T4-2-3
Remarks
Reference
Page
T4-4-12
OPERATIONAL PERFORMANCE TEST / Standard
Performance
Standard
PERFORMANCE TEST DESIGNATION
CONTROL LEVER STROKE
mm
Lift Arm Raise Position (STD/MF)
Lift Arm Raise Detent Position (STD/MF)
Lift Arm Lower Position (STD/MF)
Lift Arm Lower Float Position (STD/MF)
Bucket Lever Tilt Position (STD/MF)
Bucket Lever Tilt Detent Position (STD/MF)
Bucket Lever Dump Position (STD/MF)
Steering Wheel Rotation
(Right Max. to Left Max.)
Forward/Reverse Lever (F/R)
Accelerator Pedal Depressing Angle
(without play)
Brake Pedal (Right) Depressing Angle
(without play)
Inching Pedal (Left) Depressing Angle
(without play)
Steering Wheel Play
Brake Pedal Play
ELECTROLYTE DENSITY
(Specification at 20 °C)
2
TIRE INFLATION
kPa (kgf/cm , psi)
Remarks
Reference
Page
T4-4-13
34±5/63±10
54±5/80±10
34±5/63±10
54±5/80±10
34±5/63±10
54±5/80±10
54±5/80±10
3.5 to 4.0
50±5/50±5
18.0°±1.5
18.4°±1.0
17.4°±1.0
5 to 15
12 to 20
1.26
425 (4.34, 62)
NOTE: STD: Standard Lever (Two-Lever)
MF: Multi-Function Lever (Joystick Lever)
T4-2-4
Allowable Limit: 1.16
-
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
PRIMARY PILOT PRESSURE
2
MPa (kgf/cm , psi)
SECONDARY PILOT PRESSURE
2
MPa (kgf/cm , psi)
Performance
Standard
4.0+1.0-0.5
+10
(41 -5, 580+142-71)
3.7+0.5-0.3
+5
(38 -3, 538+73-64)
Remarks
Reference
Page
T4-5-1
T4-5-3
SOLENOID VALVE SET PRESSURE
2
MPa (kgf/cm , psi)
Solenoid Valve Unit Set Pressure
MAIN PUMP DELIVERY PRESSURE
2
MPa (kgf/cm , psi)
Value indicated on Dr.
ZX±0.2 (2, 28)
2.0+1.0-0.5
+10
(20 -5, 100+142-71)
Value indicated on Dr.
ZX
In neutral, Value indicated on Dr. ZX
T4-5-4
T4-5-6
T4-5-8
MAIN RELIEF VALVE PRESSURE
2
MPa (kgf/cm , psi)
Lift Arm (Relief operation)
Bucket (Relief operation)
OVERLOAD RELIEF PRESSURE
2
MPa (kgf/cm , psi)
Lift Arm Raise
Bucket Roll-In
Bucket Roll-Out
MAIN PUMP FLOW RATE
STEERING RELIEF PRESSURE
(L/min)
2
MPa (kgf/cm , psi)
SERVICE BRAKE PRESSURE
2
(Forward/Reverse)
MPa (kgf/cm , psi)
PARKING BRAKE PRESSURE
2
MPa (kgf/cm , psi)
29.4+2.0-0.5
(300+20-5, 4274+284-71)
29.4+2.0-0.5
(300+20-5, 4274+284-71)
(Reference values at
50 L/min)
36.8+1.0-0
(375+10-0, 5350+142-0)
32.5+1.0-0
(332+10-0, 4725+142-0)
32.5+1.0-0
(332+10-0, 4725+142-0)
+2.0
29.4 -0.5
(300+20-5, 4274+284-71)
4.18±0.85
(42.7±8.7, 608±124)
3.7+0.5-0.3
+5
(38 -3, 538+73-44)
BRAKE ACCUMULATOR PRESSURE
Value indicated on Dr.
ZX
Value indicated on Dr.
ZX
T4-5-12
Value indicated on Dr.
ZX
at Brake Pedal (Right)
T4-5-14
T4-5-10
T4-5-20
T4-5-22
T4-5-24
2
MPa (kgf/cm , psi)
Service Brake
Parking Brake
BRAKE WARNING PRESSURE
2
(Pressure-Decreasing)
MPa (kgf/cm , psi)
BRAKE WARNING PRESSURE
2
(Pressure-Increasing)
MPa (kgf/cm , psi)
TRANSMISSION CLUTCH PRESSURE
2
MPa (kgf/cm , psi)
TORQUE CONVERTER PRESSURE
2
(Inlet/Outlet)
MPa (kgf/cm , psi)
14.7±1.0
(150±10, 2137±145)
3.7+0.5-0.3
+5
(38 -3, 538+73-44)
8±0.5
(82±5, 1163±73)
10±0.5
(102±5, 1454±73)
2.2 to 2.4
(22 to 24, 320 to 349)
0.99 to 1.09(10.1 to
11.1, 144 to 158)/0.43
to 0.53(4.4 to 5.4, 63 to
77)
T4-2-5
T4-5-26
T4-5-28
T4-5-30
T4-5-31
OPERATIONAL PERFORMANCE TEST / Standard
 ZW310 GENERAL STANDARD
The standard performance values are listed in the
table below. Refer to the Group T4-3 or later for
performance test procedures.
Acceletor Pedal
: Full Stroke
Driving Mode Switch : H Mode
Work Mode Switch : N Mode
Hydraulic Oil Temperature : 505 C (12241 F)
The following switch positions shall be selected and
the hydraulic oil temperature shall be maintained as
indicated below as the preconditions of performance
tests unless otherwise instructed in each performance
test procedure:
PERFORMANCE TEST DESIGNATION
ENGINE SPEED (FAN SPEED min/max) min-1
Slow Idle Speed (without load)
Fast Idle Speed (without load)
Fast Idle Speed (with torque converter
stalled)
Fast Idle Speed (with torque converter
stalled and relieved)
VALVE CLEARANCE (IN, EX)
mm
LUBRICANT CONSUMPTION
(Rated output)
mL/h
DRIVE BELT BEND
mm
RADIATOR CAP OPENING PRESSURE
kPa (kgf/cm2, psi)
Performance
Standard
84025
2120/211025
NOTE: 1 mm=0.03937 in
Reference
Remarks
Page
T4-3-1
Value indicated on Dr. ZX

1980/192050

1710/170050

0.4/0.6
40 or less
-
T4-2-6
With the engine cold
Hour meter: 2000 hours or
less
Auto adjustment
-
T4-3-5
T4-3-8
-
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
TRAVEL SPEED
km/h
First Gear (Forward/Reverse)
Second Gear (Forward/Reverse)
Third Gear (Forward/Reverse)
Fourth (Forward/Reverse)
SERVICE BRAKE CAPACITY
m
SERVICE BRAKE WEAR
mm
Brake Disc
Brake Ring (t=15)
Brake Ring (t=5)
PARKING BRAKE CAPACITY
mm/5 min
PARKING BRAKE WEAR
mm
Brake Disc
Brake Ring
BUCKET STOPPER CLEARANCE
mm
BELL CRANK STOPPER CLEARANCE
mm
FRONT PIN WEAR
mm
(to new pin outer diameter)
FRONT BUSHING WEAR
mm
(to new pin outer diameter)
CLEARANCE BETWEEN FRONT PIN
AND BUSHING
mm
BUCKET BUMP
mm
HYDRAULIC CYLINDER CYCLE TIME sec
Lift Arm Raise
Lift Arm Lower (Float)
Bucket Roll-Out
Steering (engine: neutral)
Steering (engine: full)
DIG FUNCTION DRIFT CHECK mm/15 min
Lift Arm Cylinder
Bucket Cylinder
Bucket Bottom
Performance
Standard
7.0/7.0±0.7
11.8/11.8±1.2
21.8/21.8±2.2
34.5/34.5±3.5
5.0 or less
Remarks
Reference
Page
T4-4-1
Value indicated on Dr. ZX
↑
↑
↑
T4-4-2
T4-4-3
6.2
15.0
5.0
0
Allowable Limit: 5.3
Allowable Limit: 13.5
Allowable Limit: 4.5
2.2
2.4
0
Allowable Limit: 1.9
Allowable Limit: 2.2
T4-4-4
-
T4-4-6
T4-4-6
2
-
Allowable Limit: -1.0
-
-
Allowable Limit: -1.5
-
0.3
14
T4-4-11
T4-4-8
5.4±0.3
3.0±0.3
1.1±0.3
2.8±0.3
2.5±0.3
T4-4-10
45 or less
15 or less
150 or less
T4-2-7
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
Performance Standard
CONTROL LEVER OPERATING FORCE
N (kgf, lbf)
Lift Arm Raise (STD/MF)
Lift Arm Raise Detent (STD/MF)
Lift Arm Raise Detent Release (STD/MF)
Lift Arm Lower (STD/MF)
Lift Arm Lower Float (STD/MF)
Lift Arm Lower Float Release (STD/MF)
Bucket Lever Tilt (STD/MF)
Bucket Lever Tilt Detent (STD/MF)
Bucket Lever Tilt Detent Release (STD/MF)
Bucket Lever Dump (STD/MF)
Steering Wheel (Right/Left)
11 (1.1, 2.5)/
19 (1.9, 4.3) or less
17 (1.7, 3.8)/
30 (3.1, 6.8) or less
40 (4.1, 9)/
20(2.0, 4.5) or less
11 (1.1, 2.5)/
19 (1.9, 4.3) or less
17 (1.7, 3.8)/
30 (3.1, 6.8) or less
40 (4.1, 9)/
20 (2.0, 4.5) or less
12 (1.2, 2.7)/
22 (2.2, 5) or less
18 (1.8, 4)/
33 (3.3, 7.4) or less
40 (4.1, 9)/
20 (2.0, 4.5) or less
17(1.7, 3.8)/
28 (2.9, 6.3) or less
17 (1.7, 3.8)/
17 (1.7, 3.8) or less
Forward/Reverse Lever
11.8+1-2
(1.2+0.1-0.2, 2.7+0.2-0.5)/
11.8+1-2
(1.2+0.1-0.2, 2.7+0.2-0.5)
Accelerator Pedal
25.0±3.5
(3. 6±0.4, 5.6±0.8)
Brake Pedal Right
318+65-45
(32.4+6.6-4.6, 71.6+14.6-10.1)
Inching Pedal Left
288+80-30 (29.4+8.2-3.1,
64.8+18-6.8)
NOTE: STD: Standard Lever (Two-Lever)
MF: Multi-Function Lever (Joystick Lever)
T4-2-8
Remarks
Reference
Page
T4-4-12
OPERATIONAL PERFORMANCE TEST / Standard
Performance
Standard
PERFORMANCE TEST DESIGNATION
CONTROL LEVER STROKE
mm
Lift Arm Raise Position (STD/MF)
Lift Arm Raise Detent Position (STD/MF)
Lift Arm Lower Position (STD/MF)
Lift Arm Lower Float Position (STD/MF)
Bucket Lever Tilt Position (STD/MF)
Bucket Lever Tilt Detent Position (STD/MF)
Bucket Lever Dump Position (STD/MF)
Steering Wheel Rotation
(Right Max. to Left Max.)
Forward/Reverse Lever (F/R)
Accelerator Pedal Depressing Angle
(without play)
Brake Pedal (Right) Depressing Angle
(without play)
Inching Pedal (Left) Depressing Angle
(without play)
Steering Wheel Play
Brake Pedal Play
ELECTROLYTE DENSITY
(Specification at 20 °C)
2
TIRE INFLATION
kPa (kgf/cm , psi)
Remarks
Reference
Page
T4-4-13
34±5/63±10
54±5/80±10
34±5/63±10
54±5/80±10
34±5/63±10
54±5/80±10
54±5/80±10
3.5 to 4.0
50±5/50±5
18.0°±1.5
18.4°±1.0
17.4°±1.0
5 to 15
12 to 20
1.26
330(3.37, 48)
NOTE: STD: Standard Lever (Two-Lever)
MF: Multi-Function Lever (Joystick Lever)
T4-2-9
Allowable Limit: 1.16
-
OPERATIONAL PERFORMANCE TEST / Standard
PERFORMANCE TEST DESIGNATION
PRIMARY PILOT PRESSURE
2
MPa (kgf/cm , psi)
SECONDARY PILOT PRESSURE
2
MPa (kgf/cm , psi)
Performance
Standard
4.0+1.0-0.5
+10
(41 -5, 580+142-71)
3.7+0.5-0.3
+5
(38 -3, 538+73-64)
Remarks
Reference
Page
T4-5-1
T4-5-3
SOLENOID VALVE SET PRESSURE
2
MPa (kgf/cm , psi)
Solenoid Valve Unit Set Pressure
MAIN PUMP DELIVERY PRESSURE
2
MPa (kgf/cm , psi)
Value indicated on Dr.
ZX±0.2 (2, 28)
2.0+1.0-0.5
+10
(20 -5, 100+142-71)
Value indicated on Dr.
ZX
In neutral, Value indicated on Dr. ZX
T4-5-4
T4-5-6
T4-5-8
MAIN RELIEF VALVE PRESSURE
2
MPa (kgf/cm , psi)
Lift Arm (Relief operation)
Bucket (Relief operation)
OVERLOAD RELIEF PRESSURE
2
MPa (kgf/cm , psi)
Lift Arm Raise
Bucket Roll-In
Bucket Roll-Out
MAIN PUMP FLOW RATE
STEERING RELIEF PRESSURE
(L/min)
2
MPa (kgf/cm , psi)
SERVICE BRAKE PRESSURE
2
(Forward/Reverse)
MPa (kgf/cm , psi)
PARKING BRAKE PRESSURE
2
MPa (kgf/cm , psi)
29.4+2.0-0.5
(300+20-5, 4274+284-71)
29.4+2.0-0.5
(300+20-5, 4274+284-71)
(Reference values at
50 L/min)
36.8+1.0-0
(375+10-0, 5350+142-0)
32.5+1.0-0
(332+10-0, 4725+142-0)
32.5+1.0-0
(332+10-0, 4725+142-0)
+2.0
29.4 -0.5
(300+20-5, 4274+291-73)
4.18±0.85
(42.7±8.7, 608±124)
3.7+0.5-0.3
+5
(38 -3, 538+73-44)
BRAKE ACCUMULATOR PRESSURE
Value indicated on Dr.
ZX
Value indicated on Dr.
ZX
T4-5-12
Value indicated on Dr.
ZX
at Brake Pedal (Right)
T4-5-14
T4-5-10
T4-5-20
T4-5-22
T4-5-24
2
MPa (kgf/cm , psi)
Service Brake
Parking Brake
BRAKE WARNING PRESSURE
2
(Pressure-Decreasing)
MPa (kgf/cm , psi)
BRAKE WARNING PRESSURE
2
(Pressure-Increasing)
MPa (kgf/cm , psi)
TRANSMISSION CLUTCH PRESSURE
2
MPa (kgf/cm , psi)
TORQUE CONVERTER PRESSURE
2
(Inlet/Outlet)
MPa (kgf/cm , psi)
14.7±1.0
(150±10, 2137±145)
3.7+0.5-0.3
+5
(38 -3, 538+73-44)
8±0.5
(82±5, 1163±73)
10±0.5
(102±5, 1454±73)
2.2 to 2.4
(22 to 24, 320 to 349)
0.99 to 1.09(10.1 to
11.1, 144 to 158)/0.43
to 0.53(4.4 to 5.4, 63 to
77)
T4-2-10
T4-5-26
T4-5-28
T4-5-30
T4-5-31
OPERATIONAL PERFORMANCE TEST / Standard
MAIN PUMP P-Q CURVE
P-Q Control (Torque Control)
(REFERENCE: Measured at Test Stand)
• Rated Pump Speed: 2000 min-1 (rpm)
• Hydraulic Oil Temperature: 50±5 °C (122±41 °F)
L/min
A
B
C
D
Flow
Rate
Delivery Pressure
A
B
C
D
MPa (kgf/cm2)
Delivery Pressure
MPa (kgf/cm2, psi)
Flow Rate
L/min (gpm)
4.9 (50, 712)
19.6 (200, 2849)
26.5(270, 3853)
29.4(300, 4274)
340±3 (90±0.8)
340±3 (90±0.8)
315±6 (83±1.6)
283±6 (75±1.6)
T4-2-11
T4GB-04-02-001
OPERATIONAL PERFORMANCE TEST / Standard
P-Q Control by Pump Control Pilot Pressure
Signal
(REFERENCE: Measured at Test Stand)
• Rated Pump Speed: 2000 min-1 (rpm)
• Hydraulic Oil Temperature: 50±5 °C (122±41 °F)
L/min
A
Flow
Rate
B
C
Pump Control Pressure
MPa (kgf/cm2)
Pi1－Pi2
A
B
C
Pump Control Pressure
(Pi1－Pi2)
MPa (kgf/cm2, psi)
Flow Rate
L/min (gpm)
0.39+0.01-0 (4+0.1-0, 57+1.5-0)
1.47±0.05 (15±0.5, 214±7)
1.67+0.01-0 (17+0.1-0, 243+1.5-0)
340±3 (90±0.8)
100±2 (26±0.5)
51±3 (13±0.8)
T4-2-12
T4GB-04-02-002
OPERATIONAL PERFORMANCE TEST / Standard
SENSOR ACTIVATING RANGE
1. Checking Method
• Hydraulic Oil Temperature: 50 ± 5 °C (122±41 °F)
• Unless specified:
Engine
Speed
Fast Idle
Work Mode
Switch
N
• Monitor each sensor by using Dr. ZX.
2. Sensor Activating Range
Item
Pump Delivery Pressure
Implement Pressure
Parking Brake Pressure
Service Brake Pressure
Specification
MPa (kgf/cm2, psi)
Neutral
1.2 to 2.6 (12 to 27, 174 to 378)
Relieved
28.7 to 32.0 (293 to 327, 4172 to 4652)
Neutral
1.2 to 2.6 (12 to 27, 174 to 378)
Implement Lever: Relieved
28.7 to 32.0 (293 to 327, 4172 to 4652)
Parking Brake Switch: ON
0 to 0.1 (0 to 1, 0 to 15)
Parking Brake Switch: OFF
3.6 to 4.3 (37 to 44, 523 to 625)
Brake Pedal: Neutral
0 to 0.1 (0 to 1, 0 to 15)
Brake Pedal: Fully De- 3.3 to 5.0 (34 to 51, 480 to 727)
pressed
Operation
T4-2-13
OPERATIONAL PERFORMANCE TEST / Standard
(Blank)
T4-2-14
OPERATIONAL PERFORMANCE TEST / Engine Test
ENGINE SPEED
Summary
1. Measure the engine speed by using the monitor
unit or Dr. ZX.
2. Measure the engine speeds in each mode.
NOTE: If the engine speed is not adjusted correctly,
all other performance data will be unreliable. Consequently, measure the engine
speed before performing all other tests in
order to check that the engine speed meets
specification.
Preparation:
1. Select the monitor which is started on the service
mode or Engine Actual Speed on the main controller screen by Dr. ZX.
2. Warm up the machine until coolant temperature
reaches 50 C (122 F) or more, hydraulic oil
temperature is 505 C (12241 F) and Transmission oil temperature is 855 C (18541 F).
M4GB-01-039
Measurement:
1. Measure the items as followings: slow idle with no
load), fast idle (with no load), fast idle (when engine stalls) and fast idle (when engine stalls and
is relieved).
2. When measuring, set the switch and test condition as shown in the table below in response to
the engine speed to be measured.
Forward/Reverse Lever Accelerator Pedal Travel Mode Switch
Slow Idle
N
No depression
M
(with no load)
Fast Idle
Forward third/fourth gear Full depression
M
(with no load)
Fast Idle
(when torque converter
N
Full depression
M
stalled)
Fast Idle
(when torque converter Forward third/fourth gear Full depression
M
stalled and is relieved)
T4-3-1
Work Mode Switch
N
N
N
N
OPERATIONAL PERFORMANCE TEST / Engine Test
Slow Idle
(with no load)
Fast Idle
(with no load)
Fast Idle
(when engine
stalls)
Fast Idle
(when engine stalls
and is relieved)
Clutch Cut Position
Switch
Brake Pedal
Parking Brake
Switch
-
-
ON
S
Full depression
ON
OFF
Full depression
OFF
Transporting position
No control lever operation
OFF
Full depression
OFF
Transporting position
Bucket is raised and
relieved.
Evaluation:
Refer to Operational Performance Standard in Group
T4-2.
Remedy:
Refer to Troubleshooting in Section T5.
T4-3-2
Control Lever (Bucket)
Transporting position
No control lever operation
Transporting position
No control lever operation
OPERATIONAL PERFORMANCE TEST / Engine Test
(Blank)
T4-3-3
OPERATIONAL PERFORMANCE TEST / Engine Test
ENGINE COMPRESSION PRESSURE
Summary:
1. Measure compression pressure in the cylinders
by using a measuring tool (minidiag 2)
2
1
Preparation:
1. Run the engine until the coolant temperature
gauge reaches the operating range.
2. Install cable (2) to minidiag 2 (1).
3. Remove cover (3) on the right side in cab. Install
cable (2) to the inside connector.
Then, minidiag 2 (1) is turned ON.
IMPORTANT: If disconnecting the connector of
injector, fuel cannot be jetted.
Therefore, ECM judges that the fuel
system is faulty and the fault code
is displayed. After measurement,
delete the displayed fault code.
Measurement:
1. With the key switch OFF, operate minidiag 2 (1).
(As for the procedures, refer to the next page.)
2. Select the screen for the engine copression
pressure.
3. As the command that the key switch starts is displayed on the screen, turn the key switch to the
START position and run the starter.
4. Run the starter until the starter stops by itself.
T4GB-04-03-005
Right Side in Cab
Evaluation:
When the starter stops, the result is displayed on the
screen of minidiag 2 (1).
Remedy:
Refer to the engine shop manual.
T4GB-04-03-006
3
T4-3-4
OPERATIONAL PERFORMANCE TEST / Engine Test
Operating Procedures
6. Push ↓ and select 03. Push OK.
1. When minidiag 2 is installed to the machine, the
following display is selected. Push ↓ and select 2.
Push OK.
T4GB-04-03-012
7. When the key switch is turned to the START position on the following screen, the engine runs at
cranking speed. Then, data is read by minidiag 2.
Keep the key switch in the START position until
the engine cranking stops.
T4GB-04-03-007
2. Select 1 and push OK.
T4GB-04-03-008
3. This screen shows search in progress.
T4GB-04-03-013
8. The starter stops and the result screen is displayed.
Cylinder No.
and Result
T4GB-04-03-009
4. Select 1 and push OK.
The result is displayed.
This is OK.
T4GB-04-03-014
9. Push ←, → and select the objective cylinder.
The result is displayed on the screen.
5. Push ↓ and select 3. Push OK.
T4GB-04-03-010
T4GB-04-03-015
When finishing, push «.
When selecting the cylinder,
push ←, →.
T4GB-04-03-011
T4-3-5
OPERATIONAL PERFORMANCE TEST / Engine Test
VALVE CLEARANCE
2
Summary:
1. Perform the measurement when the engine is
cold.
2. Before starting any work, clean the head cover
mounting area and avoid contamination in the
engine.
Preparation:
1. Remove bolt (2) from head cover (1).
2. Remove the cover from sight glass (3) on the
flywheel housing.
3. Rotate the flywheel. Align the top dead center
(TDC) mark on flywheel with pointer (4) in the
flywheel housing.
NOTE: Rotate the flywheel in the following procedures.
Method 1: Install the rotating tool (DaimlerChrysler 407-589-0063-00)
(5) to sight glass (3) in the flywheel housing. Rotate the flywheel.
Method 2: Rotate the flywheel by using stop
switch (6) and start switch (7) in
upper on the engine.
Turn the key switch ON. Push
start switch (7). When the TDC
mark is aligned with pointer (4),
push stop switch (6) and stop the
flywheel.
If start switch (7) and stop switch
(6) are pushed at the same time,
the flywheel does not rotate. As
this method burns the battery
power, finish the work as soon as
possible.
NOTE: If the intake and exhaust valves are closed,
the cylinder is positioned at TDC in the
compression stroke.
T4GB-04-03-023
3
4
T4GB-04-03-022
Rotating Tool
(DaimlerChrysler 407-589-0063-00)
5
6
T4GB-04-03-027
7
T4GB-04-03-024
T4-3-6
OPERATIONAL PERFORMANCE TEST / Engine Test
Measurement:
Adjusting Screw
1. Rotate the flywheel and set cylinder No.1 (or cylinder No.6) to the measuring position.
2. Insert a thickness gauge into the clearance between rocker arm (1) and valve bridge (2). Measure the valve clearance.
NOTE: The cylinders are aligned from No.1 to
No.6 in that order, as viewed from the fan
side.
Injection Order: 1-5-3-6-2-4
3. Measure the valve with the mark { in the table
below of piston No.1 positioned at TDC in the
compression stroke. (Measure the valve with the
mark × in the table below of piston No.6 positioned at TDC in the compression stroke.)
Cylinder No.
Valve locations
When the measurement is
started from cylinder No.1
When the measurement is
started from cylinder No.6
No.1
I
E
No.2
I
E
{
{
{
×
Bridge Cap
T4GB-04-03-003
No.3
I
E
{
×
No.4
I
E
{
×
No.5
I
E
No.6
I
E
{
×
×
×
I: Inlet Valve, E: Exhaust Valve
Evaluation:
Refer to Operational Performance Standard in Group
T4-2.
Adjustment:
If the measurement results are out of specification,
adjust the valve clearance.
1. Loosen lock nut (3).
2. Straightly insert a thickness gauge into the clearance between the end of rocker arm (1) and the
cap in valve bridge (2).
3. Tighten adjusting screw (4) of rocker arm (1) until
condition for the thickness gauge is proper.
: 50 N⋅m (5.1 kgf⋅m,
lbf⋅ft)
4. Tighten lock nut (5).
Check the valve clearance again.
4
3
1
Insert a thickness
gauge.
Insert a thickness
gauge.
2
T4-3-7
T4GB-04-03-025
OPERATIONAL PERFORMANCE TEST / Engine Test
LUBRICANT CONSUMPTION
Measuring Method
1. Place the machine on level firm ground and leave
the machine for at least one hour in order to let
the lubricant lower to the oil pan when the engine
stops.
At this time, confirm that the machine is level by
using a leveler.
2. Record read-out A (unit: hour) of the hour meter.
3. Replenish the lubricant up to the high-level
gauge.
4. Operate the machine for at least 100 hours or until the oil level lowers to the low-level gauge.
IMPORTANT: Keep the machine-leaving time in
Step 1 above.
5. Place the machine on level firm ground and leave
the machine for at least one hour in order to let
the lubricant lower to the oil pan when the engine
stops.
At this time, confirm that the machine is level by
using a leveler.
6. Record read-out B (unit: hour) of the hour meter.
7. Replenish the lubricant up to the high-level
gauge while measuring the oil-replenishing volume C.
NOTE: When measuring, use a high-precision
measuring cylinder or the like.
8. Determine lubricant consumption from the following equation:
Oil replenishing volume (C) [mL] / Operating
hours (B-A) [hr]
Evaluation:
Refer to Operational Performance Standard in Group
T4-2.
T4-3-8
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
TRAVEL SPEED
6. Convert the measurement value to be expressed
in km/h.
Measurement value (seconds) = S (sec)
Converted value (hourly speed) = A (km/h)
Summary:
1. The overall performance of the travel drive system
(torque converter through transmission) is judged
by measuring the time necessary for traveling 50
m (164 ft).
A=
Preparation:
1. Adjust air pressure of the tires evenly in advance.
Air pressure:
EU: 330 kPa (3.37 kgf/cm2, 48 psi)
General: 425 kPa (4.34 kgf/cm2, 62 psi)
2. On a firm level and uniform supporting surface,
prepare a 50 m (164 ft) straight travel course, and
70 m (230 ft) forward and backward runways. (For
measurement at Speed 4, a forward runway of
300 m (984 ft) is needed.)
3. Empty the bucket, and hold the lift arm afloat 0.4
to 0.5 m (1 ft 4 in to 1 ft 8 in) above the ground.
4. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F). Warm the axle oil satisfactorily by
repeating travel and brake operations.
Make a warm up operation so that the indicators
of the engine water temperature monitor and the
torque converter oil temperature monitor rise
above the horizontal positions.
50 × 600
S × 1000
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to the Trouble Shooting in Section T5.
0.4 to 0.5 m
(1’4” to 1’8”)
Ending Point
Travel Course
Runway
Starting Point
T4GB-04-04-001
Measurement
CAUTION: Avoid measurement at reverse for
fear of dangers involved.
1. Make measurement for each mode (Speeds 1 to
4).
2. Select the switches as follows.
Parking Brake
Accelerator
Shift Switch
Switch
Pedal
Speed 1
Speed 1
OFF
Full depression
Speed 2
Speed 2
OFF
Full depression
Speed 3
Speed 3
OFF
Full depression
Speed 4
Speed 4
OFF
Full depression
3. Put the forward-reverse lever at the F (Forward)
position. From the runway, travel by depression
the accelerator pedal to the stroke end.
4. Measure the travel speed (sec) of each travel
mode.
5. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
T4-4-1
Travel Mode
Switch
H
H
H
H
Work Mode
Switch
N
N
N
N
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
SERVICE BRAKE FANCTION CHECK
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Summary:
1. The overall performance of the service brake is
judged.
2. The braking capability of the brake is an item of
safety control. Be sure to conduct the performance test.
Preparation:
1. Adjust air pressure of the tires evenly in advance.
Air pressure:
EU: 330 kPa (3.37 kgf/cm2, 48 psi)
General: 425 kPa (4.34 kgf/cm2, 62 psi)
2. On a paved dry road, prepare a 100 m (328 ft)
straight travel course (a 50 m (164 ft) of runway
and a 50 m (164 ft) of measurement road), and
set the brake starting point.
3. Empty the bucket, and hold the lift arm afloat 0.4
to 0.5 m (1 ft 4 in to 1 ft 8 in) above the ground.
4. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F). Warm the axle oil satisfactorily by
repeating travel and brake operations.
Make a warm up operation so that the indicators
of the engine water temperature monitor and the
torque converter oil temperature monitor rise
above the horizontal positions.
Remedy:
Refer to the Trouble Shooting in Section T5.
0.4 to 0.5 m
(1’4” to 1’8”)
Stopping Distance
Stopping Point
Brake Starting
Point
T4GB-04-04-002
Measurement
CAUTION: Avoid measurement at reverse for
fear of dangers involved. (Forward-reverse
lever: F)
1. Make measurement for high-speed mode.
2. Select the switches as follows.
Shift Switch
Parking Brake Switch
Speed 4
OFF
Accelerator
Pedal
Full depression
3. Put the forward-reverse lever at the F (Forward)
position. From the runway, travel at 20 km/h (12
mph) by depression the accelerator pedal to the
stroke end.
4. Depression the brake at the brake starting point,
and completely stop the vehicle. (Right Service
Brake Pedal)
5. Measure the distance from the brake starting
point to the point where the front tire is contacting.
6. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
T4-4-2
Travel Mode
Switch
Work Mode
Switch
Clutch Cut Position
Switch
H
N
OFF
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
SERVICE BRAKE WEAR AMOUNT
1
Summary:
The extent of wear of the brake disc at the service
brake of the axle is judged by the wear gauge.
Preparation:
1. Clean the inspection plug (1) of the axle, and
loosen it.
2. In the case of the rear axle, the inspection plug (1)
is located below the center line of the differential,
so loosen the inspection plug (1) after draining the
axle oil.
T4GB-04-04-004
2
Measurement:
1. Operate the service brake by depression the
brake pedal.
2. Insert the wear gauge (2) into the inspection port
until it contacts the brake disc (6) between the
brake ring (3) and the brake ring (4).
Inspection Port
T4GB-04-04-005
Evaluation:
1. In case the wear gauge (2) has entered between
the brake rings (3 and 4), and the model scale of
the wear gauge (2) and the housing face (5) have
coincided, the wear amount of the brake disc (6)
is not reached the maximum allowable limit of use.
In case the wear gauge (2) has not entered between the brake rings (3 and 4), and the model
scale is sticking above the housing face (5), the
brake disc (6) is worn in excess of the maximum
allowable limit of use.
2. In the method above, in case the maximum allowable limit of use has not reached, or in case
the service brake portion has been assembled,
refer to the Performance Standard Table in Group
T4-2.
Distance between Housing Face (5) and Brake
Disc (6)
Model
Dimensions (L) mm
ZW310
57
T4-4-3
5
2
L
6
3
4
T4GB-04-04-006
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
PARKING BRAKE FUNCTION CHECK
Summary:
1. The function of the parking brake on a determined
slope is measured.
2. The braking capability of the brake is an item of
safety control. Be sure to conduct the performance test.
Preparation:
1. Make measurement on a plane slope of 11.31 °
(20 %).
2. Empty the bucket, and hold the lift arm afloat 0.4
to 0.5 m (1’4” to 1’8”) above the ground.
3. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F).
4. Warm the axle oil satisfactorily by repeating travel
and brake operations.
Make a warm up operation so that the indicators
of the engine water temperature monitor and the
torque converter oil temperature monitor rise
above the horizontal positions.
0.4 to 0.5 m
(1’4” to 1’8”)
11.31° (20%)
T4GB-04-04-003
Measurement:
1. Travel up the slope, and put the parking brake
switch at the P position.
2. Stop the engine.
3. After the body has stopped, put a mark (white
line) on the tire and the ground surface respectively.
4. After Five minutes have passed, measure the
amount of movement of the white line of the tire
from that of the ground surface.
5. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-4-4
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
(Blank)
T4-4-5
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
BUCKET STOPPER AND BELL CRANK
CLEARANCE
Summary;
Wear and deformation conditions of the bucket
stopper (dump end and crowd end) and the clearance between the bell crank stopper and the cross
tube are measured.
Preparation:
Stop the vehicle on a plane road surface, and operate the parking brake.
Bucket Dump
Stopper
Bell Crank Stopper
Measurement:
1. Bucket dump stopper
1-1. Raise the lift arm to the highest lifting position,
and stop the engine.
1-2. At stop of the engine, dump calmly until the
buket contacts the dump stopper. At this time,
measure the Strokes (A and B) of the bucket
cylinder and the lift arm and the dump angle (C)
of the bucket. In addition, measure the clearance between the bell crank stopper and the
cross tube.
1-3. At the same time, make measurement of the
contact conditions of the bucket dump stoppers
(left and right).
2. Bucket crowd stopper
1-1. Raise the lift arm until the lift arm cylinder stroke
(E) becomes the length of the standard dimension.
1-2. Set the engine at idling speed, and make
crowding operation until the bucket calmly contacts the bucket crowd stopper.
1-3. At this time, measure the strokes (D and E) of
the bucket cylinder and the lift arm cylinder and
the crowd angle (F) of the bucket. In addition,
measure the height (G) from the ground to the
bucket lowest portion.
1-4. Also measure the contact conditions of the
bucket crowd stoppers (left and right).
T4GB-04-04-008
Bucket Crowd
Stopper
T4GB-04-04-010
T4-4-6
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
Evaluation:
1. Bucket Dumper Stopper
1-1. Cylinder Stroke Strokes A and B
Bucket Cylinder
Lift Arm Cylinder
Model
A (mm)
B (mm)
ZW310
510±1.5
1168±2
2. Bucket Crowd Stopper
2-1. Cylinder Strokes D and E
Bucket Cylinder
Model
D (mm)
ZW310
839
1-2. Bucket Dump Angle C
Model
C (°)
ZW310
50±2
2-2. Bucket Crowd Angle (F)
Model
F (°)
ZW310
50
1-3. Clearance between Bell Crank Stopper and
Cross Tube
Clearance between Bell Crank
Model
Stopper and Cross Tube
(mm)
Standard
2.0
ZW310
Limit
-
2-3. Height from Ground to Bucket Lowest Portion
(G)
Model
G (mm)
ZW310
480
1-4. Clearance between Bucket Dump Stopper and
Lift Arm
Clearance at Longitudinal and
Unsymmetrical Lateral Clearance
Model
Contact
of a Stopper
(mm)
(mm)
Standard
0
0
ZW310
Limit
1.0
1.0
Clearance at Unsymmetrical Contact
Clearance at Unsymmetrical Contact
Clearance Limit
Left
Right
Clearance Limit
Right
Longitudinal and Lateral Clearance of a Stopper
Left
Right
Right
T4GB-04-04-009
Clearance Limit
Left
2-4. Clearance between Bucket Dump Stopper and
Lift Arm
Clearance at Longitudinal and
Unsymmetrical Lateral Clearance
Model
Contact
of a Stopper
(mm)
(mm)
Standard
0
0
ZW310
Limit
1.0
1.0
Longitudinal and Lateral Clearance of a Stopper
Clearance Limit
Left
Lift Arm Cylinder
E (mm)
380
T4GB-04-04-009
T4-4-7
NOTE: Standard dimensions indicate those of a
new tire at the designated air pressure.
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
HYDRAULIC CYLINDER CYCLE TIME
Lift Arm Cylinder:
Summary:
1. The overall performance of the cylinders drive
system (main pump through each cylinder) is
judged by measuring the operating time of the
cylinders for the lift arm, bucket, and steeering.
2. The bucket is made empty in advance.
(for Lifting)
Preparation:
1. Measurement is made for the following positions.
1-1. Measurement of Lift Arm Cylinder (for Liftig)
Fully crowd the bucket, and lower the lift arm.
1-2. Measurement of Lift Arm Cylinder (for Lowering)
Lower the lift arm until the bucket bottom face
touches the ground horizontally.
1-3. Measurement of Bucket Cylinder
Lift the lift arm to the highest position.
1-4. Measurement of Steering Cylinder
Empty the bucket, and take the travel forward
position.
T4GB-04-04-016
(for Lowering)
2. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F).
CAUTION: Select ground filled with sand or
something so that the bucket contacts the
ground with buffer.
T487-04-03-005
Bucket Cylinder:
T487-04-03-006
Travel Position
0.4 to 0.5 m
(1’4” to 1’8”)
M4GB-04-001
T4-4-8
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
Measurement:
1. Select the pedal, switches, and forward-reverse
lever as follows.
Parking Brake
Accelerator Pedal
Switch
Lift Arm
Full Stroke
ON
(for Lifting)
(Engine Maximum Speed)
Lift Arm
Neutral
ON
(for Lowering)
(Engine Minimum Speed)
Full Stroke
Bucket
ON
(Engine Maximum Speed)
Neutral
Steering
OFF
(Engine Minimum Speed)
Full Stroke
Steering
OFF
(Engine Maximum Speed)
2. Make measurement operation as follows.
(including the buffer range)
2-1. Measurement of Lift Arm Cylinder (for Lifting)
Operate the lift arm lever to the stroke end, and
measure the time of movement of the lift arm
from the lowest position to the highest position.
2-2. Measurement of Lift Arm Cylinder (for Lowering)
Lower the bucket to the ground in the horizontal
position, and lift the lift arm to the highest position.
Keep the lift arm lever at the afloat position, and
measure the time of movement of the bucket
reaching the ground.
2-3. Measurement of Bucket Cylinder
Operate the bucket lever to the stroke end, and
measure the time of movement of the bucket
from the full crowd position to the full dump position.
2-4. Measurement of Steering Cylinder
Operate the steering wheel to the stroke end,
and measure the time of movement of the
steering wheel from the right to the left end, and
from the left to the right end.
CAUTION: Before measurement, confimr
that there are no human beings or obstacles
in the steering range.
3. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to the Trouble Shooting in Section T5.
T4-4-9
Forward-reverse
Lever
Work Mode
Switch
N
N
N
N
N
N
N
N
N
N
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
CYLINDER DRIFT CHECK
Summary:
1. Internal leakage of the lift arm, bucket cylinders,
and control valves when the buket is loaded with
load equivalent to the standard load is judged by
the settlement (shrinkage) of the cylinder rod.
2. Measurement is made in the standard front condition (standard bucket).
3. In case measurement is made immediately after
the cylinder replacement, conduct air venting of
the cylinder before measurement by operating the
cylinders slowly to the stroke ends several times.
Preparation:
1. Load the bucket with weight or sand equivalent to
the standard load
ZW220: 7180 kg (15829 lb)
ZW250: 6400 kg (14109 lb)
2. In the front position, extend the lift arm to the
maximum reach, and hold the bucket at an agle of
about 5° declined forward from full crowding.
Bucket Cylinder
CAUTION: Never allow any personnel to be
under the bucket.
1. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement of
Settlement
Lift Arm
Cylinder
Measurement:
1. Stop the engine.
2. After 15 minutes have passed, measure the
shrinkage of the lift arm cylinder, shrinkage of the
bucket cylinder, and the settlement of the bucket
bottom respectively.
3. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4GB-04-04-014
B
A
T4GB-04-04-015
Remedy:
Refer to the Trouble Shooting in Section T5.
T4-4-10
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
BUCKET LEVELNESS
Summary:
Left and right inclinations of the bucket are checked
in order to prevent uneven wear of the cutting edge
of the bucket.
Preparation:
1. Place the unloaded base machine on a horizontal
bed on rhe ground. (In case a bed is not available,
place it on a horizontal flat concrete on the ground.
Deal with the measurement values as guide
lines.)
2. Adjust the tire air pressure to the designated
value.
3. Have the bucket bottom contact the ground horizontally.
Cutting Edge
Measurement:
1. Have the bucket bottom float slightly above the
bed.
2. Measure the vertical distance from the bed and
the bottom face of the cutting edge on the left and
right ends, and confirm the difference.
3. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
CAUTION: Never put hands, feet, and measuring instruments under the bucket.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-4-11
T4GB-04-04-011
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
CONTROL LEVER OPERATING FORCE
Summary
1. Operating conditions of the levers, pedals, and
steering wheel are confirmed, and their operating
force are measured.
2. Maximum operating force of the levers, pedals,
and steering wheel are measured.
3. Measurement of each of the operating levers is
made at the center of the grip.
Measurement of each of the pedals is made at
150 mm (6 in) from the pedal support.
Travel Position
Preparation:
1. In the front position, empty the bucket in advance.
2. Keep the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement
1. Make measurement for each of the operating
levers, pedals, and steering wheel.
2. Select the pedal, switches, and forward-reverse
lever as follows.
Parking
Forward-reverse
Accelerator Pedal
Brake Switch
Lever
Neutral
(Engine Minimum
ON
N
Speed)
0.4 to 0.5 m
(1’4” to 1’8”)
M4GB-04-001
CAUTION: Before measurement, confimr
that there are no human beings or obstacles
in the steering range.
3. Apply a spring balance scale (tension type) to
each of the lift arm, bucket, and froward-reverse
lever, and measure their maximum operating efforts by operating them to the stroke end.
4. In the case of the pedals, apply a spring balance
scale (compression type) or a load cell to them,
and measure their operating efforts when they are
stepped slightly.
5. For the steering wheel, apply a spring balance
scale (tension type) to the knob, and measure the
maximum operating effort when it is moved.
6. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-4-12
T4GB-04-04-013
Knob
M4GB-01-004
Brake Pedal
Accelerator Pedal
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
CONTROL LEVER STROKE
Summary:
1. Plays and operating conditions of operating levers,
pedals, and steering wheel are confirmed, and
their strokes are measured.
2. Measurement of each of the operating levers is
made at the tip of the grip.
Measurement of each of the pedals is made at the
top of the pedal.
3. In the case of existence of play at neutral, make
measurement by dividing it on both sides evenly.
Preparation:
1. Keep the hydraulic oil temperature at 50±5 °C
(122±40 °F).
Measurement:
1. Measurement of Operating Lever
1-1. Have the bucket bottom contact the ground.
1-2. Stop the engine.
1-3. Measure the stroke from the neutral position to
the stroke end of each of the lift arm, bucket,
and forward-reverse operating levers at the top
center of the grip.
2. Measurement of Pedal
2-1. Have the bucket contact the ground.
2-2. Stop the engine.
2-3. Measure the stroke from the neutral position to
the stroke end of the pedal at the top of the
pedal.
3. Measurement of Steering Wheel
3-1. Start the engine. (Low idling)
3-2. Have the bucket float slightly above the ground.
3-3. Measure the number of times of rotation required for reaching the left stroke end from the
right, and vice versa of the steering wheel.
4. make measurement corresponding to a straight
line.
5. Make measurement three times, and determine
the measurement value by obtaining their mean
values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-4-13
OPERATIONAL PERFORMANCE TEST / Wheel Loader Test
(Blank)
T4-4-14
OPERATIONAL PERFORMANCE TEST / Component Test
PRIMARY PILOT PRESSURE
(Including Brake Circuit)
CAUTION: If air is mixed in the brake system,
the brake function is reduced, and serious
hazard may occur. Bleed air from the brake
system after removing and installing the pipe
lines and replacing hydraulic oil.
Refer to Troubleshooting B in Group T5-6.
IMPORTANT: Primary pilot pressure circuit shuts
off a circuit connecting to pilot relief
valve if pressure in the accumulator
is insufficient, and delivers primary
pilot pressure to accumulator circuit.
At this time, primary pilot pressure
reaches 15 MPa (153 kgf/cm2, 2180
psi) or high, so use a pressure
gauge capable of measuring 15 MPa
(153 kgf/cm2, 2180 psi) or higher.
Hose
(3/4-16UNF)
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Remove the hose end from the pilot filter inlet or
outlet port. Install adapter (13/16-16UNF), nipple,
pressure gauge and coupling.
: 22 mm, 24 mm, 27 mm
Pilot Filter
T4GB-04-05-001
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the accelerator pedal fully.
2. Measure pilot pressure without load by using a
pressure gauge.
3. Repeat the measurement three times and calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
NOTE: When pressure in the service brake accumulator is reduced during measurement
of primary pilot pressure, the measured
valve is increased to 15 MPa (153 kgf/cm2,
2180 psi) for several seconds.
T4-5-1
T1F3-04-05-001
OPERATIONAL PERFORMANCE TEST / Component Test
Primary Pilot Pressure Adjustment Procedure
Adjustment:
Adjust the relief valve set-pressure in charging block
as necessary.
1. Remove plug (1) from the relief valve.
: 30 mm
2. Remove shim (2) from the relief valve.
3. Install the estimated number of shim (2).
4. Install shim (2) to the relief valve.
Tighten plug (1).
: 98.0±9.8 N⋅m
(960±95 kgf⋅m, 710±71 lbf⋅ft)
Charging Block
M4GB-07-100
5. Check the set-relief pressure.
Charging Block
NOTE: Standard Change in Pressure (Reference)
Set the thickness of shims at less than 1.5 mm.
Shim Thickness
Change in Pressure
(mm)
kPa
(kgf/cm2)
(psi)
0.2
61.8
(0.63)
(9)
0.4
124.6
(1.27)
(18)
0.8
249.2
(2.54)
(36)
1
X
X
T4GB-04-05-002
Section X-X
1
T4GB-04-05-003
2
T4-5-2
OPERATIONAL PERFORMANCE TEST / Component Test
SECONDARY PILOT PRESSURE
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Measure pressure at the location between pilot
valve and main valve.
Remove the pilot hose to be measured. Install
the hose (9/16-18UNF length: approx. 400 mm)
to the signal control valve side. Install a tee and a
pressure gauge between the hoses.
: 17 mm, 19 mm, 22 mm
Pilot Valve
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the accelerator pedal fully.
2. Measure pilot pressure by using a pressure
gauge with the corresponding control lever operated full stroke.
3. Repeat the measurement three times and calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting in Section T5.
T4-5-3
Pilot Hose
Signal Control
Valve
Pressure Gauge
Tee
T4GB-04-05-004
OPERATIONAL PERFORMANCE TEST / Component Test
SOLENOID VALVE SET PRESSURE
Measure solenoid valve set pressure by using both Dr.
ZX and the pressure gauge.
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Remove the line from port X in the charging block.
Install a tee, a hose and adapter (ST 6461). Install pressure gauge (ST 6942).
: 17 mm, 19 mm, 22 mm
Install Dr. ZX and select the monitoring function.
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Charging Block
Solenoid
Valve
Measurement:
1. Set engine speed at fast idle.
2. Measure without depressing the accelerator
pedal.
Measure with the accelerator pedal fully depressed.
3. Read the values on both Dr. ZX and the pressure
gauge.
4. Repeat the measurement three times and calculate the average values.
Port X
T4GB-04-05-005
Pressure Gauge
Evaluation:
Refer to the performance Standard Table in Group
T4-2.
To Port X
T4GB-04-05-006
Hose
T4-5-4
Tee
Adapter
OPERATIONAL PERFORMANCE TEST / Component Test
Solenoid Valve Set Pressure Adjustment Procedure
IMPORTANT: O-ring on the threads may come off
the sealing surface and oil leak may
occur. Do not loosen and tighten the
adjusting screw excessively.
Do not loosen the adjusting screw
more than 1.2 turns. Do not tighten
the adjusting screw more than 2
turns.
1. Loosen lock nut (1). Turn adjusting screw (2) and
adjust set pressure of the solenoid valve.
2. Retighten lock nut (1).
: 18 mm
: 19.6 N⋅m (2 kgf⋅m, 14 lbf⋅ft)
: 6 mm
1
2
T4GB-04-05-007
Charging Block
3. Check the set pressure of solenoid valve.
NOTE: Standard Change in Pressure (Reference)
Adjusting Screw
1/4
1/2
3/4
1
Turns
kPa
39.2
80.4
120
160
Change in
(kgf/cm2) (0.4) (0.82) (1.22) (1.63)
Pressure
(psi)
(6)
(12)
(17)
(23)
T4GB-04-05-002
2
Pressure
Increase
Pressure
Decrease
W107-02-05-129
T4-5-5
OPERATIONAL PERFORMANCE TEST / Component Test
MAIN PUMP DELIVERY PRESSURE
The main pump delivery pressure can also be measured by using Dr. ZX.
Summary:
Measure the main pump delivery pressure in order to
check performance of the main pump.
Pressure
Gauge
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Remove the plug from the main pump delivery
port. Install an adapter, a hose and a pressure
gauge.
: 6 mm
(If Dr. ZX is used, install Dr. ZX and select the
controller function diagnosing.)
4. Start the engine. Check for any leaks at the pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the accelerator pedal fully.
2. Measure pressure without load (with the control
levers in neutral).
3. Repeat the measurement three times and calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting in Section T5.
T4-5-6
Pressure
Check Port
T4GB-04-05-008
Adapter
OPERATIONAL PERFORMANCE TEST / Component Test
(Blank)
T4-5-7
OPERATIONAL PERFORMANCE TEST / Component Test
MAIN RELIEF PRESSURE
The main relief pressure can also be measured by
using Dr. ZX.
Summary:
Measure the main relief valve set pressure at the
main pump delivery port in order to check performance of the main relief valve.
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Remove the plug from the main pump delivery
port. Install an adapter, a hose and a pressure
gauge.
: 6 mm
(If Dr. ZX is used, install Dr. ZX and select the
controller function diagnosing.)
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the accelerator pedal fully.
2. Slowly operate the lift arm or bucket control levers to the stroke end (extend or retract) and relieve each function.
3. Repeat the measurement three times and calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-5-8
Pressure
Gauge
Pressure
Check Port
T4GB-04-05-008
Adapter
OPERATIONAL PERFORMANCE TEST / Component Test
Main Relief Valve Pressure Adjustment Procedure
1. Loosen lock nut (1).
: 17 mm
2. Turn adjusting screw (2) and adjust the relief
pressure to the specification.
: 6 mm
3. Tighten lock nut (1).
: 29.4 N⋅m (3 kgf⋅m, 22 lbf⋅ft)
4. Check the relief set pressure.
1
2
T4GB-04-05-011
NOTE: Standard Change in Pressure (Reference)
Adjusting Screw
1/4
1/2
3/4
1
Turns
Change in
Pressure
MPa
(kgf/cm2)
(psi)
4.5
(46)
(654)
8.9
(91)
(1294)
13.4
(137)
(1948)
17.8
(182)
(2588)
2
Pressure
Increase
Pressure
Decrease
W107-02-05-129
T4-5-9
OPERATIONAL PERFORMANCE TEST / Component Test
STEERING RELIEF PRESSURE
The steering relief pressure can also be measured by
using Dr. ZX.
Pressure Gauge
Summary:
Measure the steering relief valve set pressure at the
main pump delivery port in order to check performance of the steering relief valve.
Preparation:
1. Stop the engine.
2. Pusht the air bleed valve on top of the hydraulic
oil tank and release any remaining pressure.
3. Remove the plug from the main pump delivery
port. Install an adapter, a hose and a pressure
gauge.
: 6 mm
(If Dr.ZX is used, install Dr.ZX and select the controller function diagnosing.)
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the accelerator pedal fully.
2. Install the articulation lock bar. Slowly operate the
steering handle and relieve the steering.
3. Repeat the measurement three times and calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-5-10
Pressure
Check Port
Adapter
T4GB-04-05-008
OPERATIONAL PERFORMANCE TEST / Component Test
Steering Relief Valve Pressure Adjustment Procedure
1. Secure lock nut (1). Remove nut (3).
: 24 mm
2. Secure adjusting screw (2). Loosen lock nut (1).
: 24 mm
3. Turn adjusting screw (2) and adjust the relief
pressure to the specification.
4. Secure adjusting screw (2). Tighten lock nut (1).
: 37 N⋅m(3.8 kgf⋅m, 27 lbf⋅ft)
5. Secure lock nut (1). Tighten nut (3).
: 37 N⋅m(3.8 kgf⋅m, 27 lbf⋅ft)
6. Check the relief set pressure.
Steering Relief
Valve
T4GB-04-05-012
3
1
NOTE: Standard Change in Pressure (Reference)
Adjusting Screw
1/4
1/2
3/4
1
Turns
Change in
Pressure
MPa
(kgf/cm2)
(psi)
3.8
(39)
(552)
7.5
(77)
(1050)
11.3
(155)
(1643)
15.0
(153)
(2181)
2
T4GB-04-05-013
2
Pressure
Increase
Pressure
Decrease
T105-06-05-002
T4-5-11
OPERATIONAL PERFORMANCE TEST / Component Test
OVERLOAD
PRESSURE
RELIEF
VALVE
SET
Summary:
1. The circuit pressure must be increased by
applying an external force while blocking the
return circuit from the control valve. This
measuring method is hazardous and the results
obtained with this method are unreliable.
2. The oil flow rate used to set the overload relief
pressure is far less than that used to set the main
relief pressure. Therefore, measuring the overload
pressure in the main circuit by increasing the main
relief set-pressure more than the overload valve
set-pressure is not a proper method. In addition, in
case a main relief valve designed to leak a small
quantity of oil before reliving is used, its
pre-leaking start pressure must be increased
more than the overload relief valve set-pressure.
However, the pre-leaking start pressure is not
always increased more than the overload relief
valve set-pressure as the adjustable upper limit of
the main relief valve set-pressure is provided.
Accordingly, the overload relief valve assembly
should be removed from the machine and
checked on a specified test stand at a correct oil
flow rate. Some overload relief valves come in
contact with the control valve body to block the oil
passage. When this type of overload relief valve is
checked, the control valve body must be precisely
finished as the test unit. Provide one control valve
other than that on the machine as a test kit.
4. Install Dr. ZX and select the monitoring function.
Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Measurement:
1. Set engine speed at fast idle. Depress the
accelerator pedal fully.
2. Slowly operate the control levers (lift arm or
bucket) corresponding to the overload relief valve
to be measured to the stroke ends (extend and
retract) and relieve each function.
3. Read the pressures on the pressure gauge at this
time.
4. Repeat the measurement three times and
calculate the average values.
Evaluation:
Performance of the overload relief valves are normal if
the measured main relief pressures are within the
specified value range.
Refer to the Performance Standard Table in Group
T4-2.
Pressure
Gauge
3. If the overload relief valve performance must be
checked on the machine, however, measure the
main relief pressure while releasing each front
function respective to the measuring overload
relief valve. And, assume that the overload relief
valve is functioning correctly if the obtained main
relief pressure is within the specified value range.
Measure the main pressure of the front functions
by using Dr. ZX.
Preparation:
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
3. Remove the plug from the main pump delivery
port. Install an adapter, a hose and a pressure
gauge.
: 6 mm
T4-5-12
Pressure
Check Port
Adapter
T4GB-04-05-008
OPERATIONAL PERFORMANCE TEST / Component Test
Overload Relief
Procedure
Valve
Pressure
Adjusting
NOTE: In principle, adjust the overload relief valve
pressure on a test stand.
Adjust the pressure setting of the overload relief valve
with adjusting screw (2) after loosening lock nut (1).
1
1. Loosen lock nut (1).
: 17 mm
2. Turn adjusting screw (2) and adjust the pressure.
: 6 mm
3. Tighten lock nut (1).
: 17 mm
: 29.5 N⋅m (3.0 kgf⋅m, 22 lbf⋅ft)
2
W107-02-05-128
4. Check the set pressure.
NOTE: Standard Change in Pressure (Reference)
Adjusting Screw
1/4
1/2
3/4
1
Turns
MPa
5.2
10.6
15.9
21.1
Change in
(kgf/cm2) (54)
(108)
(162)
(216)
Pressure
(psi)
(770) (1540) (2300) (3070)
2
Pressure
Increase
Pressure
Decrease
W107-02-05-129
T4-5-13
OPERATIONAL PERFORMANCE TEST / Component Test
MAIN PUMP FLOW RATE
• P-Q Control (Torque Control)
Summary:
Main pump performance is checked by measuring
the pump flow rate by using a hydraulic tester
installed at the main pump delivery port to be
measured. Use Dr. ZX and a pressure gauge at the
same time.
IMPORTANT: This measurement procedure is a
simple method. The measured data
will be lower by approx. 5 % than the
accurately measured value. In order
to measure accurately, disconnect
the return circuit from the control
valve and connect it to the hydraulic
oil tank.
Preparation:
1. Stop the engine. Push the air bleed valve and
release any remaining pressure. Install a vacuum
pump to the oil filler port.
NOTE: Operate the vacuum pump while
connecting the pump flow rate test line.
2. Remove the delivery hose from the main pump.
Install pipe (1) to split flange (8) in the removed
hose with the bolt.
: 41 mm
: 10 mm
3. Connect pipe (1) to hydraulic tester (4) with test
hose (2) and adapter (3). Install adapter (5), joint
(6) and flange (7).
: 41 mm
: 10 mm
4. Connect flange (7) to the delivery hose with split
flange (8) and bolt (9).
: 10 mm
5. Install a pressure gauge to the main pump. (Refer
to the page on Main Pump Relief Pressure.)
: 6 mm
6. Remove hose (11) from the regulator. Install plug
(G1/4) to the hole on hose (11).
: 17 mm
7. Remove the vacuum pump. Loosen plug (10) on
top of the pump casing. Bleed air from the pump
casing until oil only comes out of the plug
clearance.
8. Fully open the loading valve of hydraulic tester.
9. Start the engine. Check for any oil leaks at the
pressure gauge connection. Install Dr. ZX and
select the monitor display function of MC.
Measurement:
1. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
2. Measure the maximum flow rate.
3. Set engine speed at fast idle. Depress the
accelerator pedal fully.
4. Adjust the main relief valve set pressure in the
control valve to each pressure point specified
along the main pump P-Q curve. (Refer to T4-2.)
Slowly close the loading valve of the hydraulic
tester while relieving the pressure in the bucket
crowd circuit. Measure the flow rates and engine
speeds at the pressure points specified in the P-Q
curve.
5. Repeat the measurement three times and
calculate the average values.
T4-5-14
OPERATIONAL PERFORMANCE TEST / Component Test
Evaluation:
1. Convert the measured flow rates to those at the
specified pump speed by using the following
formulas:
2. Standard Flow Rate
Refer to the Performance Standard Table in Group
T4-2.
Qc = (Ns × Q) ⁄ Ne
Qc : Converted Flow Rate
Q : Measured Flow Rate
Ns : Specified Engine Speed: 2000 min-1
Ne : Measured Engine Speed:
Value by Dr. ZX
1
2
3
5
4
6
7
8
9
Delivery Hose
(To Control Valve)
T1F3-04-05-010
10
11
T4GB-04-05-014
1 - Pipe
2 - Test Hose
3 - Adapter (PF1× UNF1-7/8)
456-
Hydraulic Tester
Adapter (PF1×UNF1-7/8)
Joint
789-
T4-5-15
Flange
Split Flange
Bolt (4 Used)
10 - Plug
11 - Hose
OPERATIONAL PERFORMANCE TEST / Component Test
• Pilot Characteristics
Summary:
Main pump performance is checked by measuring
the pump flow rate by using a hydraulic tester
installed at the main pump delivery port to be
measured. Use Dr. ZX and a pressure gauge at the
same time.
IMPORTANT: This measurement procedure is a
simple method. The measured data
will be lower by approx. 5 % than the
accurately measured value. In order
to measure accurately, disconnect
the return circuit from the control
valve and connect it to the hydraulic
oil tank.
Preparation:
1. Refer to steps 1 to 4 on page T4-5-14. Install a
hydraulic tester to the main pump.
2. Remove the hose from regulator port Pi1 of the
pump. Install a plug to the removed hose.
: 19 mm
3. Install adapters (13) (3 used) to pressure reducing
valve (14). Remove the hose from port P of the
orbit roll. Insert tee (10), adapter (11) and hose
(12) between orbit roll and charging block.
Install hose (12) to port P1 on reducing valve (14).
: 19 mm
4. Install tee (15) to port P2 on pressure reducing
valve (14). Install pressure gauge (16) and hose
(12) to tee (15). Install hose (12) to regulator port
Pi1.
: 19 mm
5. Install hose (12) and adapter (13) to port T on
pressure reducing valve (14). Remove plug L
from the return pipe. Install hose (12).
: 19 mm
6. Connect regulator port Pi2 to the hydraulic oil tank.
As for the emergency steering, install tee (17),
adapter (18) and hose (19) to port E in the
emergency steering block. Install hose (19) to
regulator port Pi2.
: 17mm
7. Remove the vacuum pump. Loosen the plug on
top of the pump casing. Bleed air from the pump
casing until oil only comes out of the plug
clearance.
8. Fully open the loading valve of the hydraulic
tester.
9. Start the engine. Check for any oil leaks at the
pipe connection.
Measurement:
1. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F)
2. The pump flow rate in response to the external
command pilot pressure is measured.
3. Set engine speed at fast idle. Depress the
accelerator pedal fully
4. Adjust the pressure reducing valve set pressure
to each pressure point specified along the main
pump P-Q curve. (Pilot Characteristics) (Refer to
T4-2.) Measure the flow rates and engine speeds
at the pressure points specified in the P-Q curve.
5. Repeat the measurement three times and
calculate the average values.
Evaluation:
1. Convert the measured flow rates to those at the
specified pump speed by using the following
formulas:
Qc = (Ns × Q) / Ne
Qc : Converted Flow Rate
Q : Measured Flow Rate
Ns : Specified Engine Speed : 2000 min-1
Ne : Measured Engine Speed
Value by Dr. ZX
2. Standard Flow Rate
Refer to the Performance Standard Table in
Group T4-2.
T4-5-16
OPERATIONAL PERFORMANCE TEST / Component Test
1
2
3
5
4
6
7
8
9
Delivery Hose
(To Control Valve)
T1F3-04-05-010
Port Pi2
Port Pi1
Pilot Steering Valve
Port P
Pilot Steering
Valve Port P Hose
T4GB-04-05-025
Charging Block
T4GB-04-05-026
Pressure Reducing
Valve Port Position
Emergency
Steering
Check Block
Return Pipe
T
17
L
P1
P2
19
13
To Regulator
Port Pi2
12
16
13
To Hydraulic
Oil Tank
To Port P in Pilot
Steering Valve
To Regulator
Port Pi1
12
Charging
Block
15
13
6 - Test Hose
2 - Test Hose
7 - Flange
3 - Adapter (G1 × UNF1-7/8)
(ST 6146)
4 - Hydraulic Tester
8 - Split Flange (4085560)
12
13
14
1 - Pipe
5 - Adapter (G1 × UNF1-7/8)
(ST 6146)
18
Port E
9 - Bolt (J781240) (4 Used)
10 - Tee 7/16-20UNF x G1/4
11
10
11 - Adapter (9/16 UNF x G1/4)
(A852123)
12 - Hose (9/16 UNF)
(4304905)
13 - Adapter (9/16 UNF x G3/8)
(A852133)
14 - Pressure Reducing Valve
(4325439)
15 - Tee (9/16 UNF x G1/4)
T4-5-17
T1F3-04-05-009
16 - Pressure Gauge
17 - Tee
18 - Adapter
19 - Hose
OPERATIONAL PERFORMANCE TEST / Component Test
REGULATOR ADJUSTMENT
6
5
1
2
7
8
4
3
9
10
T4GB-04-05-016
1 - Lock Nut (For Minimum
Flow Rate)
2 - Adjusting Screw (For
Minimum Flow Rate)
3 - Lock Nut (For Maximum
Flow Rate)
Adjustment Item
1. Maximum Flow Rate
4 - Adjusting Screw (For
Maximum Flow Rate)
5 - Lock Nut
(For Pilot Pressure
Characteristic)
6 - Adjusting Screw
(For Pilot Pressure
Characteristic)
7 - Lock Nut
(For P-Q Control)
8 - Adjusting Screw
(For P-Q Control)
9-
Lock Nut
(For P-Q Control)
10 - Adjusting Screw
(For P-Q Control)
Adjustment Procedure
Remarks
Loosen lock nut (5) and turn 1) Do not turn adjusting screw (6) more
adjusting screw (6).
than two turns.
Rotate adjusting screw (6) 1/4 a 2) Do not increase the maximum flow
turn clockwise and the maximum
rate.
pump flow rate decreases by
In other words, do not turn adjusting
12.82 cm3/rev. (0.78 in3/rev).
screw (6) counterclockwise.
: 32 mm
3) Secure tighten lock nut (5) after the
: 40 N⋅m
adjustment.
(4.1 kgf⋅m, 30 lbf⋅ft)
T4-5-18
OPERATIONAL PERFORMANCE TEST / Component Test
Adjustment Item
Adjustment Procedure
Remarks
2. Pilot Pressure Characteristics Loosen lock nut (1) and turn 1) Do not turn the adjusting screw (2)
adjusting screw (2).
more than one turn.
Rotate adjusting screw (2) 1/4 a 2) Securely tighten lock nut (1) after
turn clockwise and the pump flow
the adjustment.
Q
rate decreases by 9.23 cm3/rev.
(0.56 in3/rev).
: 17 mm
: 20 N⋅m
(2 kgf⋅m, 15 lbf⋅ft)
Pi
A: Loosen lock nut (7) and turn 1) Do not turn the adjusting screws (8,
adjusting screw (8).
10) more than one turn.
Rotating adjusting screw (8) 2) Rotate the adjusting screws (8, 10)
1/4 a turn clockwise increases
while
watching
the
engine
and the pump flow rate
performance.
increase by 15.6 cm3/rev. 3) Securely tighten lock nuts (7, 9)
after the adjustment.
(0.95 in3/rev.).
3. P-Q Control
(Torque Adjustment)
Q
A
: 30 mm
: 30 N⋅m
(3.1 kgf⋅m, 22 lbf⋅ft)
Pd
B: Loosen lock nut (9) and turn
adjusting screw (10).
Rotating adjusting screw (10)
1/4 a turn clockwise and the
pump flow rate increases by
4.5 cm3/rev. (0.27 in3/rev).
Q
B
Pd
: 13 mm
: 10 N⋅m
(1 kgf⋅m, 7.5 lbf⋅ft)
T4-5-19
OPERATIONAL PERFORMANCE TEST / Component Test
SERVICE BRAKE PRESSURE (FRONT
AND REAR)
(The pressure can be measured by using Dr. ZX.)
CAUTION: If air is mixed in the brake system,
the brake function is reduced and serious
hazard may occur. Bleed air from the brake
system after removing and installing the pipe
lines and replacing hydraulic oil.
Refer to Troubleshooting B in Group T5-6.
Summary:
Measure the pressure at the brake valve pressure
check port when the brake pedal is depressed.
Preparation:
CAUTION: Set the block onto the front and
rear tires in order not to move the machine.
Keep away from the machine.
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
3. Depress the brake at least 50 strokes in order to
reduce the accumulated pressure left in the brake
circuit.
4. Install the measuring devices to the front and rear
wheel brake circuits.
4-1. Front wheel brake circuit pressure: Remove
plug (1) from the pressure check port in brake
valve. Install a nipple and a pressure gauge to
the pressure check port.
: 19 mm, 22 mm
: 6 mm
4-2. Rear wheel brake circuit pressure: Remove
plug (2) from the pressure check port in brake
valve. Install a nipple and a pressure gauge to
the pressure check port.
: 19 mm, 22 mm
: 6 mm
5. Start the engine. Check for any oil leaks at the
pressure gauge connection.
6. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
T4GB-04-05-017
Block
Brake Valve
T4-5-20
1
2
T4GB-04-05-018
OPERATIONAL PERFORMANCE TEST / Component Test
Conditions for Measurement:
1. Set engine speed at fast idle.
2. Depress the accelerator pedal fully.
Measurement:
1. Measure the pressure when fully depressing the
brake pedal at left side to the floor.
2. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting B in Group T5-6.
Normally, the front and rear wheel brake pressures
become equal. If not, malfunction of the brake valve
and dirt caught in the valve are suspected.
T4-5-21
OPERATIONAL PERFORMANCE TEST / Component Test
PARKING BRAKE PRESSURE
CAUTION: If air is mixed in the brake system,
the brake function is reduced and serious
hazard may occur. Bleed air from the brake
system after removing and installing the pipe
lines and replacing hydraulic oil.
Refer to Troubleshooting B in Group T5-6.
Summary:
1. Measure the parking brake release pressure in
the parking brake release circuit.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting B in Group T5-6.
Preparation:
CAUTION: Set the block onto the front and
rear tires in order not to move the machine.
Keep away from the machine.
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
3. Remove brake hose (1) from the parking brake
side. Install a pressure gauge to the removed
hose.
: 19 mm, 22 mm
4. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
T4GB-04-05-017
Block
1
Conditions for Measurement:
1. Set engine speed at fast idle.
2. Depress the accelerator pedal fully.
Measurment:
1. Release the parking brake and measure the
pressure at this time.
2. Repeat the measurement three times and
calculate the average values.
M4GB-06-004
T4-5-22
OPERATIONAL PERFORMANCE TEST / Component Test
(Blank)
T4-5-23
OPERATIONAL PERFORMANCE TEST / Component Test
BRAKE ACCUMLATED PRESSURE
(The pressure can be measured by using Dr. ZX.)
CAUTION: If air is mixed in the brake system,
the brake function is reduced serious hazard
may occur. Bleed air from the brake system
after removing and installing the pipe lines
and replacing hydraulic oil.
Refer to the Troubleshooting B in Group T5-6.
Summary:
The accumulated brake pressure is measured at
output port of the accumulator. The accumulated
brake pressure varies according to operation of the
brake. Record the maximum value.
Preparation:
T4GB-04-05-017
CAUTION: Set the block onto the front and
rear tires in order not to move machine. Keep
away from the machine.
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
3. Depress the brake at least 50 strokes in order to
reduce the accumulated pressure left in the brake
circuit.
4. Remove plug (1) from the pressure check port of
charging block in bottom of the cab.
Install a nipple and a pressure gauge to the
pressure check port.
: 19 mm, 22 mm
: 6 mm
5. Start the engine. Check for any oil leaks at the
pressure gauge connection.
6. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
Block
1
T4GB-04-05-019
T4-5-24
OPERATIONAL PERFORMANCE TEST / Component Test
Conditions for Measurement:
1. Set engine speed at fast idle.
2. Depress the accelerator pedal fully.
Measurement:
1. Measure maximum pressure when depressing
the brake pedal slowly several times.
2. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting B in Group T5-6.
T4-5-25
OPERATIONAL PERFORMANCE TEST / Component Test
BRAKE WARNING
(DECREASE)
SET
PRESSURE
(The pressure can be measured by using Dr. ZX.)
CAUTION: If air is mixed in the brake system,
the brake function is reduced serious hazard
may occur. Bleed air from the brake system
after removing and installing the pipe lines
and replacing hydraulic oil.
Refer to the Troubleshooting B in Group T5-6.
Summary:
When the warning buzzer sounds by reducing the
accumulated brake pressure, measure the pressure
at the output port of accumulator.
Preparation:
CAUTION: Set the block onto he front and
rear tires in order not to move the machine.
Keep away from the machine.
1. Stop the engine.
2. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
3. Depress the brake at least 50 strokes in order to
reduce the accumulated pressure left in the brake
circuit.
4. Remove plug (1) from the charged pressure
check port in brake valve. Install a nipple and a
pressure gauge to the pressure check port.
: 19 mm, 22 mm
: 6 mm
5. Start the engine. Check for any oil leaks at the
pressure gauge connection.
6. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
T4GB-04-05-017
Block
Blake Valve
1
T4GB-04-05-018
T4-5-26
OPERATIONAL PERFORMANCE TEST / Component Test
Conditions for Measurement:
1. Select the following switch positions.
Forward/Reverse Lever Parking Brake Switch
N
P (Parking)
Measurement:
1. Stop the engine. Turn the key switch to ON
position.
2. Measure the pressure when warning buzzer
sounds by slowly depressing the brake pedal
several times.
3. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting B in Group T5-6.
T4-5-27
OPERATIONAL PERFORMANCE TEST / Component Test
BRAKE WARNING SET PRESSURE
(INCREASE)
(The pressure can be measured by using Dr. ZX.)
CAUTION: If air is mixed in the brake system,
the brake function is reduced serious hazard
may occur. Bleed air from the brake system
after removing and installing the pipe lines
and replacing hydraulic oil.
Refer to the Troubleshooting B in Group T5-6.
Summary:
When sounding of the warning buzzer stops by
increasing the accumulated brake pressure, measure
the pressure at the output port of accumulator.
Preparation:
CAUTION: Set the block onto the front and
rear tires in order not to move machine. Keep
away from the machine.
4. Stop the engine.
5. Push the air bleed valve on top of the hydraulic oil
tank and release any remaining pressure.
6. Depress the brake at least 50 strokes in order to
reduce the accumulated pressure left in the brake
circuit.
5. Remove plug (1) from the charged pressure
check port in brake valve. Install a nipple and a
pressure gauge to the pressure check port.
: 19 mm, 22 mm
: 6 mm
6. Start the engine. Check for any oil leaks at the
pressure gauge connection.
5. Maintain the hydraulic oil temperature at 50±5 °C
(122±41 °F).
T4GB-04-05-017
Block
Blake Valve
1
T4GB-04-05-018
T4-5-28
OPERATIONAL PERFORMANCE TEST / Component Test
Conditions for Measurement:
1. Select the following switch positions.
Forward/Reverse Lever Parking Brake Switch
N
ON
Measurement:
1. Stop the engine. Turn the key switch to ON
position.
2. Set the engine control dial to slow idle.
3. Depress the brake pedal several times and make
the warning buzzer sound.
4. Start the engine. Measure the pressure when
sounding of the warning buzzer stops. Notice that
it is difficult to read the gauge as the pressure
increases rapidly.
5. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
Remedy:
Refer to Troubleshooting B in Group T5-6.
T4-5-29
OPERATIONAL PERFORMANCE TEST / Component Test
TRANSMISSION CLUTCH PRESSURE
Summary:
Measure each operating pressure of the tansmission
clutch at each port of the transmission control valve.
Reverse Clutch
Pressure
Forward Clutch
Pressure
First Gear Clutch
Pressure
Preparation:
1. Stop the engine.
2. Remove the plug from the port. Install a hose, an
adapter and a pressure gauge.
: 8 mm
: 21 mm
3. Start the engine. Check for any oil leaks at the
pressure gauge connection.
4. Maintain the torque converter oil temperature at
60 to 80 °C (140 to 176 °F).
Second Gear
Clutch Pressure
Third Gear
Clutch Pressure
Fourth Gear
Clutch Pressure
Measurement:
CAUTION: Set the block onto the front and
rear tires in order not to move machine. Keep
away from the machine.
1. Select the following switch positions.
T4GB-04-05-023
Accelerator
Pedal
Fully
Depressed
Brake Pedal
Travel Mode
Clutch Cut-Off
Position Switch
Parking Brake
Switch
Fully
Depressed
M
OFF
OFF
2. Operate the forward/reverse lever and the shift
switch. Measure each clutch pressure.
Travel Switch
Forward/Reverse
Lever
Shift Switch
F
R
1st
2nd
3rd
4th
F
R
N
N
N
N
4
4
1
2
3
4
3. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-5-30
OPERATIONAL PERFORMANCE TEST / Component Test
TORQUE CONVERTER PRESSURE (INLET
AND OUTLET)
Torque Converter
Inlet Pressure
Check Port
Summary:
Measure inlet pressure and outlet pressure of the
torque converter pressure at the port of torque
converter housing.
Preparation:
1. Stop the engine.
2. Inlet pressure:
Remove the plug from the port of regulator valve
(1). Install a hose, an adapter and a pressure
gauge to the open part.
: 6 mm
Outlet pressure:
Remove the plug from the port of torque converter
housing (2). Install a hose, an adapter and a
pressure gauge to the open part.
: 6 mm
3. Start the engine. Check for any oil leaks at the
pressure gauge connection.
4. Maintain the torque converter oil temperature at
60 to 80 °C (140 to 176 °F).
1
2
Torque Converter
Outlet Pressure
Check Port
Measurement:
CAUTION: Set the block onto the front and
rear tires in order not to move the machine.
Keep away from the machine.
1. Select the following switch positions:
T4GB-04-05-024
T4GB-04-05-017
Block
Accelerator
Pedal
Fully
Depressed
Brake Pedal
Travel Mode
Clutch Cut-Off
Position Switch
Parking Brake
Switch
Fully
Depressed
M
OFF
OFF
2. Set the front/reverse lever to “F” (Forward) and
the shift switch to “4” (Fourth Gear). Measure the
pressure.
3. Repeat the measurement three times and
calculate the average values.
Evaluation:
Refer to the Performance Standard Table in Group
T4-2.
T4-5-31
OPERATIONAL PERFORMANCE TEST / Component Test
(Blank)
T4-5-32
OPERATIONAL PERFORMANCE TEST / Adjustment
TRANSMISSION LEARNING
Relay Box
After removing and/or replacing the components as
described below for repair, perform the transmission
learning (calibration).
• Replacement or repair of the transmission
assembly, transmission control valve or clutch
pack
• Replacement or repair of MC (Main Controller)
Preparation:
1. Start the service mode in monitor. Start the engine.
(Refer to T5-1-6.)
2. Select the transmission oil temperature on the
monitor. (Refer to T5-1-7.)
3. Heat transmission oil.
3-1. Disconnect connector (1) (6-pole, gray) in the
relay box from dummy connector.
3-2. Select or operate the switches from the left item
in the table below.
T4GB-04-06-007
1
T4GB-04-06-001
Clutch Cut-Off
Position Switch
Shift Switch
Parking Brake
Switch
Brake Pedal
OFF
Second Gear
OFF
Fully
Depressed
3-3. Stall the transmission and heat transmission oil
to 90 °C (194 °F).
3-4. When transmission oil temperature on the
monitor reaches 90 °C (194 °F), return the
forward/reverse lever to neutral (N) and stop the
engine.
T4-6-1
Accelerator
pedal
Fully
Depressed
Forward/Reverse
Lever
F
OPERATIONAL PERFORMANCE TEST / Adjustment
Learning
1. Install the calibration switch to the connector
(6-pole, gray) in relay box in 10 seconds after
turning the key switch OFF (the battery relay is
tuned OFF). At this time, return the calibration
start switch to neutral.
IMPORTANT: If the battery relay is not turned OFF,
calibration cannot be performed. It
takes 10 seconds to turn the battery
relay OFF after turning the key
switch OFF.
Calibration
Switch
Calibration Start
Switch
2. Start the service mode in monitor. Start the engine.
Set engine speed at idling speed. (Refer to
T5-1-6.)
3. Select the transmission oil temperature on the
monitor. (Refer to T5-1-7.)
IMPORTANT: Do not operate each switch and lever
until calibration finishes.
4. When transmission oil temperature reaches 75 °C
(167 °F), push T/M in the calibration start switch.
The start of learning display as illustrated in the
right is selected on the monitor.
Lift Arm
T/M
T4GB-04-06-003
Start of Learning
Oil
temperature
when starting
learning
5. When learning finishes, the end of learning
display as illusrated in the right is selected on the
monitor. Return the calibration start switch to
neutral.
6. Remove the calibration switch from the connector
and stop the engine.
T4GB-04-06-004
The speed stage during learning is displayed on the
monitor.
11 to 13: First Gear, 21 to23: Second Gear,
31 to 33: Third Gear, 41 to 43: Fourth Gear,
F1 to F3: Forward, A1 to A3: Reverse
End of Learning
T4GB-04-06-006
T4-6-2
OPERATIONAL PERFORMANCE TEST / Adjustment
Error Display
When calibration fails, the error is displayed on the
monitor.
The error consists of two types; when start of
calibration fails, when calibration is aborted during
calibration.
• Error display when start of calibration fails
If the error display as figure 1 is displayed before
starting calibration, calibration cannot be
continued. After the trouble correspoding to error
No. is solved, start calibration again.
Error
No.
2
3
4
Error Display
Figure 1
Error
The forward/reverse lever is not in “N”.
The parking brake is not in “ON”.
The machine is driving.
T/M temperature is lower than
5
specification. *1
T/M temperature is higher than
6
specification. *1
Engine speed is lower than specification.
7
*2
Engine
speed
is
higher
than
8
specification. *2
*1: Error No. and T/M temperature at this time (figure
2) are displayed alternately.
*2: Error No. and engine speed at this time (figure 3)
are displayed alternately.
NOTE: If error No. 2, 3 or 4 is displayed, set the
switch and lever corresponding to this error
to the correct position so that SR is
displayed on the monitor.
If error No. 6 is displayed, wait until
transmission oil temperature reaches
specification so that SR is displayed on the
monitor.
When SR is displayed, push the calibration
start switch again and start calibration.
Error No.
T4GB-04-06-009
Figure 2
T/M
Temperature
T4GB-04-06-010
Figure 3
Engine Speed
T4-6-3
T4GB-04-06-011
OPERATIONAL PERFORMANCE TEST / Adjustment
NOTE: If error No. 5, 7 or 8 is displayed, stop the
engine. Remove the calibration switch from
the connector and solve the trouble.
Then, start calibration again.
T4-6-4
OPERATIONAL PERFORMANCE TEST / Adjustment
• Error display when calibration is aborted during
calibration
When calibration is aborted during calibration, the error
display as illustrated in the right is selected.
After the trouble is solved, start calibration again.
Error No.
000108
000208
000308
000408
000508
000109
000209
000309
000110
000210
000310
000111
000211
000311
000112
000212
000312
000113
000213
000313
000114
000214
000314
Error
The key is turned into OFF.
Engine speed is out of specification.
The parking brake is turned into OFF.
The machine starts traveling.
The forward/reverse lever is operated.
Failure of learning at first gear.
Failure of learning at second gear.
T4GB-04-06-013
Error No.
Failure of learning at third gear.
Failure of learning at fourth gear.
Failure of learning at forward.
Failure of learning at reverse.
NOTE: Cause of the error No. display on failure of
learning (from first gear to reverse): The
clutch at the speed when the error occurs
may be out of correctable range
(malfunction of drive unit parts) or the
transmission oil temperature may be
beyond the specification.
T4-6-5
OPERATIONAL PERFORMANCE TEST / Adjustment
LIFT ARM ANGLE SENSOR LEARNING
(OPTIONAL)
After removing and/or replacing the components as
described below for repair, perform the left arm angle
learning (calibration).
• Removal and installation of angle sensor,
Replacement of angle sensor
• Replacement or repair of MC (Main Controller)
Preparation:
1. Install Dr. ZX and start the engine.
Select Boom Anlge and Angle Sensor Learning
Status on the main controller screen in Dr. ZX.
1
2
2. Raise the lift arm to the highest position.
At this time, check if voltage at Boom Angle on the
display in Dr. ZX is 3.78±0.5 V.
3. If voltage 3.78±0.5 V is not displayed, the
followings may be caused. Conduct the remedy.
• The rotation shaft in angle sensor (1) turns with
sensor lever (2) together.
• Angle sensor (1) failure
4. Set control lever lock (3) to LOCK position and
stop the engine.
T4GB-04-06-008
3
LOCK
M4GB-01-050
T4-6-6
OPERATIONAL PERFORMANCE TEST / Adjustment
5. Install calibration switch (5) to connector (4)
(6-pole, gray) in relay box in 10 seconds after
turning the key switch OFF (the battery relay is
tuned OFF). At this time, return calibration start
switch (6) to neutral.
IMPORTANT: If the battery relay is not turned OFF,
calibration cannot be performed. It
takes 10 seconds to turn the battery
relay OFF after turning the key
switch OFF.
Relay Box
6. Lay down calibration start switch (6) to the lift arm
side. Start the engine at idling speed.
7. If “Finish” in Angle Sensor Learning Status on Dr.
ZX is turned into black, learning finishes. Return
calibration start switch (6) to OFF (neutral).
If “Failed” or “Not Learn” in Angle Sensor Learning
Status on Dr. ZX is turned into black, repeat the
procedures from step 1.
T4GB-04-06-007
4
8. Return the control lever lock to UNLOCK. Lower
the lift arm onto the ground. Stop the engine.
9. After learning of the lift arm angle sensor, set the
stop position of lift arm. (Refer to the Operator’s
Manual.)
T4GB-04-06-001
5
6
Lift Arm
T/M
T4GB-04-06-003
T4-6-7
OPERATIONAL PERFORMANCE TEST / Adjustment
UNIT INJECTOR SETTING
Summary:
1. After the unit injector is replaced, input the set
value of each unit by using a measuring tool
(minidiag 2)
2
1
Preparation:
1. Install cable (2) to minidiag 2 (1).
2. Remove cover (3) on the right side in cab. Install
cable (2) to the inside connector.
Then, minidiag 2 (1) is turned ON.
Measurement:
1. With the key switch OFF, operate minidiag 2 (1).
(As for the procedures, refer to the next page.)
2. Input the set value (set No.) of each unit injector
(4).
T4GB-04-03-005
3
T4GB-04-03-006
4
T4GB-04-03-016
T4-6-8
OPERATIONAL PERFORMANCE TEST / Adjustment
Setting Procedures
1. After the connector is connected, push ↓ and
select 2. Push OK.
6. Push ↓ and select 06. Push OK.
T4GB-04-03-017
T4GB-04-03-007
7. Push OK.
2. Select 1 and push OK.
T4GB-04-03-008
3. This screen shows search in progress.
T4GB-04-03-009
4. Select 1 and push OK.
5. Push ↓ and select 3. Push OK.
T4GB-04-03-010
8. Push ↓ and select the objective cylinder.
Push OK.
T4GB-04-03-018
T4GB-04-03-019
9. Push → and input setting No.(A).
T4GB-04-03-020
A
T4GB-04-03-011
T4GB-04-03-026
T4-6-9
OPERATIONAL PERFORMANCE TEST / Adjustment
10. Check input valve (A).
Push OK.
In case of Setting No.
5-497-581-42708
T4GB-04-03-021
T4-6-10
MEMO
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SECTION 5
TROUBLESHOOTING
CONTENTS
Group 1 Diagnosing Procedure
Group 3 e-Wheel
Introduction ..............................................T5-1-1
Outline .....................................................T5-3-1
Diagnosing Procedure ..............................T5-1-2
List of Daily Report Data...........................T5-3-2
How to Operate Service Made of
List of Frequency Distribution Data ...........T5-3-3
Monitor ....................................................T5-1-6
List of Total Operationg Hours ..................T5-3-4
Display List of Monitor Service Mode ........T5-1-7
List of Alarm .............................................T5-3-5
List of failure ............................................T5-3-6
Group 2 Dr.ZX
Outline .....................................................T5-2-1
Operation .................................................T5-2-2
Self-Diagnosing Result ............................T5-2-4
Select Controller.......................................T5-2-6
Main Controller .......................................T5-2-7
Main Menu Monitor Display (Main
Controller) ................................................T5-2-8
Setting (Main Controller).........................T5-2-12
Record Data Display (Main Controller)....T5-2-19
How to Download and Upload Data of
ICF ...........................................................T5-3-7
Various Setup if ICF and Satellite
Communication Terminal by Using
Dr.ZX......................................................T5-3-10
List of ICF Fault Code ............................T5-3-22
List of Fault Code of Sattellite
Communication Terminal ........................T5-3-23
Group 4 Component Layout
Password Change (Main Controller) .......T5-2-20
Main Component Layout (Overview) .........T5-4-1
Engine Controller ...................................T5-2-21
Main Component Layout (Upper-
Monitor Display (Engine Controller) ........T5-2-22
structure)..................................................T5-4-2
Recorded Data Display (Engine
Main Component Layout (Travel
Controller) ..............................................T5-2-26
System) ....................................................T5-4-3
Password Change (Engine Controller) ....T5-2-27
Electric Component Layout (Overview) .....T5-4-4
ICF Controller.........................................T5-2-29
Electrical System (Cab) ............................T5-4-5
ICF Various Setup (ICF Controller) .........T5-2-30
Engine and Fan Pump ............................T5-4-10
Save Data Check (ICF Controller) ..........T5-2-40
Pump Device, Drive Unit......................... T5-4-11
Password Change (ICF Controller) .........T5-2-41
Control Valve ..........................................T5-4-12
Monitor Unit............................................T5-2-43
Ride Control Valve ,Charging Block,
Monitoring (Monitor Unit) ........................T5-2-44
Fan Motor...............................................T5-4-13
Various Settings (Monitor Unit) ...............T5-2-46
Steering Valve, Emergency
Internal Hour Meter Synchronization.......T5-2-47
Steering Pump (Optional) .......................T5-4-14
Password Change (Monitor Unit) ............T5-2-48
Components in Control Valve..................T5-4-16
Components in Steering Valve ................T5-4-22
4HAT-5-1
Components in Charging Block ..............T5-4-26
Transmission Failure
Components in Ride Control Valve .........T5-4-32
MC Fault Code 11600 ...........................T5-5-86
Front View of Transmission ....................T5-4-36
MC Fault Code 11601 ...........................T5-5-87
Side View of Transmission .....................T5-4-37
MC Fault Code 11602 ...........................T5-5-88
Rear View of Transmission .....................T5-4-38
MC Fault Code 11904 ...........................T5-5-89
Cross-Sectional Drawing of
MC Fault Code 11905 ...........................T5-5-90
Torque Converter ...................................T5-4-39
CAN Data Reception Failure
Cross-Sectional Drawing of
MC Fault Codes 11910, 11920................T5-5-91
Transmission..........................................T5-4-40
CAN Harness Check
(MC Fault Codes 11910, 11920) .........T5-5-92
Cross-Sectional Drawing of
Clutch Shaft ...........................................T5-4-41
MC Fault Code 11914 .............................T5-5-95
Cross-Sectional Drawing of
CAN Harness Check
(MC Fault Code 11914) ......................T5-5-96
Transmission Regulator Valve ................T5-4-42
Cross-Sectional Drawing of
Other Failures
Transmission Control Valve ....................T5-4-43
MC Fault Code 11901 .............................T5-5-99
Proportional Solenoid Valve Truble
Group 5 Troubleshooting A
Troubleshooting A Procedure....................T5-5-1
MC Fault Code List...................................T5-5-2
ECM1 & ECM2 Fault Code List...............T5-5-22
ICF Fault Code List ................................T5-5-46
Satellite Terminal Fault Code List ...........T5-5-48
Monitor Unit Fault Code List ...................T5-5-50
Controller Hardware Failure
MC Fault Codes 11000 to 11002.............T5-5-51
MC Fault Code 11003.............................T5-5-52
MC Fault Code 11004.............................T5-5-53
CAN Harness Check ..............................T5-5-54
Engine Failure
MC Fault Code 11103 .............................T5-5-75
MC Fault Code 11105 .............................T5-5-76
Check...................................................T5-5-100
Each Connector Terminal Role
in ECM1 ...............................................T5-5-103
Each Connector Terminal Role
in ECM2 ...............................................T5-5-106
ICF, Satellite Terminal Fault Codes
14000 to 14003 ....................................T5-5-109
ICF, Satellite Terminal Fault Codes
14006, 14008, 14100 to 14106 ............. T5-5-113
Monitor Unit Fault Codes 13306,
13308 ................................................... T5-5-115
Monitor Unit Fault Code 13312 ............. T5-5-116
Monitor Unit Fault Code 13314 ............. T5-5-117
Monitor Unit Fault Code 13334 ............. T5-5-118
Pump Failure
MC Fault Code 11204.............................T5-5-77
MC Fault Code 11209.............................T5-5-78
Pilot Failure
MC Fault Code 11312.............................T5-5-79
MC Fault Code 11313.............................T5-5-80
Proportional Solenoid Valve Failure
MC Fault Code 11412.............................T5-5-81
MC Fault Code 11413.............................T5-5-82
MC Fault Code 11414, 11415, 11416,
11417, 11418, 11419 ..............................T5-5-83
4HAT-5-2
Group 6 Troubleshooting B
Malfunction of Transmission Oil
Troubleshooting B Procedure ...................T5-6-1
Temperature ...........................................T5-7-22
Relationship between Machine Trouble
Malfunction of Hydraulic Oil
Symptoms and Related Parts ...................T5-6-2
Temperature Indicator ............................T5-7-24
Correlation between Trouble
Malfunction of Transmission Warning
Symptoms and Part Failures ..................T5-6-18
Indicator .................................................T5-7-26
Engine System Troubleshooting .............T5-6-32
Malfunction of Air Filter Restriction
Front Attachment System
Indicator .................................................T5-7-28
Troubleshooting......................................T5-6-41
Malfunction of Engine Oil Pressure
Travel System Troubleshooting ..............T5-6-60
Indicator .................................................T5-7-30
Brake System Troubleshooting ...............T5-6-76
Malfunction of Overheat Indicator ...........T5-7-32
Steering System Troubleshooting ...........T5-6-84
Malfunction of Engine Warning
Other System Troubleshooting ...............T5-6-87
Indicator .................................................T5-7-34
Exchange Inspection ............................ T5-6-109
Malfunction of Stop Indicator ..................T5-7-35
Bleeding Air from Brake (Axle) ............. T5-6-111
Malfunction of Service Indicator..............T5-7-36
One Part of Data, “Daily Report
Malfunction of Parking Brake Indicator ...T5-7-38
Data”, “Distribution Data”, “Total
Malfunction of Clearance Light
Operationg Hours” and “Alarm” is
Indicator .................................................T5-7-40
Not Recorded ....................................... T5-4-112
Malfunction of Brake Low Oil Pressure
Indicator .................................................T5-7-41
Group 7 Troubleshooting C
Malfunction of Brake Low Oil Level
Troubleshooting C (Trouble Shooting
for Monitor) Procedure .............................T5-7-1
Malfunction of Indicator Light Check
System .....................................................T5-7-2
Malfunction of Buzzer in Monitor...............T5-7-4
Malfunction of Coolant Temperature
Gauge ......................................................T5-7-6
Malfunction of Transmission Oil
Temperature Gauge .................................T5-7-8
Malfunction of Fuel Gauge .....................T5-7-10
Malfunction of Turn Signal Indicators
(Left and Right) ......................................T5-7-12
Indicator .................................................T5-7-42
Malfunction of Emergency Steering
Indicator (Optional).................................T5-7-44
Malfunction of Low Steering Oil
Pressure Indicator (Optional) ..................T5-7-46
Malfunction of Discharge Warning
Indicator .................................................T5-7-48
Malfunction of Monitor Display................T5-7-50
Malfunction of Ride Control Indicator ......T5-7-51
Malfunction of Engine Coolant
Temperature Display...............................T5-7-52
Malfunction of Hazard Light Indicator .....T5-7-13
Malfunction of High Beam Indicator ........T5-7-14
Malfunction of Working Light Indicator....T5-7-16
Malfunction of Forward/Reverse
Switch Indicator ......................................T5-7-18
Malfunction of Maintenance Indicator .....T5-7-20
Malfunction of Preheat Indicator ...........T5-7-21
4HAT-5-3
Group 8 Electrical System Inspection
Precautions for Inspection and
Maintenance...........................................T5-8-1
Instructions for Disconnecting
Connectors .............................................T5-8-3
Fuse Inspection........................................T5-8-6
Fusible Link Inspection .............................T5-6-8
Battery Voltage Check ..............................T5-6-9
Alternator Check ....................................T5-6-10
Continuity Check ....................................T5-6-12
Voltage and Current Measurement .........T5-6-14
Check by False Signal ............................T5-6-17
4HAT-5-4
MEMO
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TROUBLESHOOTING / Diagnosing Procedure
INTRODUCTION
Refer to the inspection and troubleshooting procedures after any machine trouble has occurred. The
inspection and troubleshooting procedures are presented in an orderly fashion in this section to quickly
find the cause of the machine trouble and solution.
The troubleshooting section in this manual consists of
8 groups; Diagnosing Procedure, Dr. ZX, e-Wheel,
Component Layout, Troubleshooting A (base machine
diagnosis by using fault codes), Troubleshooting B
(base machine diagnosis starting with inspection of
abnormal operational status), Troubleshooting C
(monitor diagnosis) and Electrical System Inspection.
• Dr. ZX
• Troubleshooting A (base machine diagnosis by
This group contains the operating procedures for
Dr. ZX.
using fault codes)
Refer to these procedures if any fault codes are
displayed when each controller of ICF (information controller) is diagnosed by using Dr. ZX (or
the service mode of monitor).
• e-Wheel
Refer to these procedures if any fault codes are
displayed when ICF (information controller) and
satellite communication controller are diagnosed
by using Dr. ZX. (ICF and satellite communication
controller self-diagnosing functions retain a record of the electrical signal system malfunction in
the form of fault codes. At the same time, as the
satellite communication controller sends information onto CAN, the fault code of satellite communication controller can be checked by using ICF.)
This group contains as follows.
Download data from ICF and Upload
Various setting procedures when starting satellite
communication, when installing the satellite
communication controller and when replacing
ICF
Explanation for the satellite communication system
IMPORTANT: Each
controller self-diagnosing
function retains a record of the electrical signal system malfunction in
the form of fault codes. At the same
time, as each controller sends information onto CAN, the fault code
of all controllers can be checked by
using ICF.)
ICF records the fault code of each
controller and the date when the
malfunction occurs.
• Component Layout
Refer to this group when required to check where
the components and inner parts are located.
• Troubleshooting B (base machine diagnosis
starting with inspection of abnormal operational
status)
Refer to these procedures when no fault codes
are displayed after diagnosing the machine with
Dr. ZX (or the service mode of monitor).
• Troubleshooting C (monitor diagnosis)
Refer to these procedures when gauges and/or
indicators are malfunctioning.
• Electrical System Inspection
Refer to this group when required to obtain precautions and/or information for the electrical system inspection.
T5-1-1
TROUBLESHOOTING / Diagnosing Procedure
DIAGNOSING PROCEDURE
These six basic steps are essential for efficient
troubleshooting:
1. Study the System
Study the machine’s technical manuals. Know the
system and how it works, and what the
construction, functions and specifications of the
system components are.
2. Ask the operator
Before inspecting, get the full
malfunctions from the operator below.
story
of
T4GB-05-01-001
(a) How is the machine being used? (Find out if
the machine is being operated correctly)
(b) When was the trouble noticed, and what
types of work the machine doing at that
time?
(c) What are the details of the trouble? Is the
trouble getting worse, or did it appear
suddenly for the first time?
(d) Did the machine have any other troubles
previously? If so, which parts were repaired
before?
3. Inspect the machine
Before starting the troubleshooting procedure,
check the machine’s daily maintenance points, as
shown in the operator's manual.
T4GB-05-01-002
Also, check the electrical system, including the
batteries, as troubles in the electrical system
such as low battery voltage, loose connections
and blown fuses will result in malfunction of the
controllers, causing total operational failure of the
machine.
If troubleshooting is started without checking for
blown fuses, a wrong diagnosis may result,
wasting time. Check for blown fuses before
troubleshooting. Even if a fuse looks normal by
visual inspection, a fine crack is difficult to find.
Always use a tester when checking the fuses.
T4GB-05-01-003
T5-1-2
TROUBLESHOOTING / Diagnosing Procedure
4. Operate the machine yourself
Try to identify the trouble by operating the
machine yourself.
If the trouble cannot be confirmed (this states
are repeated that the trouble is resolved later
altough the trouble sometimes occurs), stop the
engine and obtain further details of the
malfunction from the operator.
Also, check for any incomplete connections of
the wire harnesses correponding to the trouble.
NOTE: It should take time to required to find the
malfunction according to the trouble during
the troubleshooting. The malfunction may
occur due to up and down of hydraulic
temperature, weather and under the
special condition including expansion by
heat and shorted harness by moisture. The
informations of weather when the
mulfunction occurs, time from the engine
start to the trouble occurrence are also
important.
T5-1-3
TROUBLESHOOTING / Diagnosing Procedure
5. Perform troubleshooting
CAUTION: Do not disconnect harnesses or
hydraulic lines while the engine is running.
The machine may malfunction or pressurized
oil may spout, possibly resulting in personal
injury. Stop the engine before disconnecting
harnesses or hydraulic lines.
Perform diagnosis by connecting Dr. ZX to the
machine or by using the service mode of monitor.
In case any fault code has been displayed by diagnosis by using Dr. ZX or the service mode of
monitor, check the cause of the trouble by referring to Troubleshooting A in this section. In case
any fault code has been displayed by diagnosis
by using Dr. ZX or the service mode of monitor,
write the fault code. Delete the fault code once
and retry self-diagnosis again. If the fault code is
displayed again, check the cause of the trouble
by referring to Troubleshooting A in this section.
After the machine trouble has been corrected, the
fault code (displayed by the service mode of
monitor) will be deleted. Therefore, in case problems which are not easily re-predicable are encountered (this states are repeated that the
trouble is resolved later altough the troubole
sometimes occurs), check the fault code by using
Dr. ZX.
NOTE: As for teach controller, the fault code and
date when the trouble occurred, which are
recorded by ICF, are effective in order to
resolve the problem which are not easily
re-predicable. (Refer to e-Wheel in this
section.)
T4GB-05-01-004
T4GB-05-01-005
In case the fault code is not displayed, check
operating condition of each component by referring to Troubleshooting B in this section and by
using Dr.ZX or the service mode of monitor.
T4GB-05-01-006
T5-1-4
TROUBLESHOOTING / Diagnosing Procedure
Note that the fault codes displayed do not
necessarily indicate machine trouble. The
controller stores even temporary electrical
malfunctions, such as a drop in battery output
voltage or disconnections of the switches,
sensors, etc., for inspections.
For this reason, the “RETRIAL” is required to
erase the accumulated fault codes from the
controller memory and to confirm if any fault
codes are indicated after the “RETRIAL”.
6. Trace possible causes
Before reaching a conclusion, check the most
likely causes again. Try to identify the actual
cause of the trouble.
Based on your conclusion, make a plan for
appropriate repairs to avoid consequent
malfunctions.
T5-1-5
TROUBLESHOOTING / Diagnosing Procedure
HOW TO OPERATE SERVICE MODE OF
MONITOR
In case the engine starts in normal, the monitor is
started in normal mode and only the items, which can
be displayed in normal mode, are displayed on the
liquid crystal display (LCD). (Refer to the next page.)
How to Used Monitor in Service Mode
1. Whenever pushing the monitor display selector
(up) in the monitor, the display in information display is changed.
When the monitor is started in service mode according to the following procedures, the items which can
be displayed in normal mode, the fault code and one
part of monitor items can be displayed. (Refer to the
next page.)
NOTE: The fault code is indicated in the display
order 11. All fault codes can be indicated.
In case more than one fault code is indicated, they will be displayed with an interval of 1 second in order. After the machine
malfunction has been repaired, the fault
codes are automatically deleted. Accordingly, if any trouble, which is not reproducible, is encountered (this states are
repeated that the trouble is resolved later
altough the troubole sometimes occurs), it
is recommended to use Dr. ZX in order to
check the fault code history.
How to Start Monitor in Service Mode
1. Push the monitor display selector (up) and
(down) in the monitor at the same time and the
key switch is turned ON.
NOTE: The engine can start in normal.
Liquid Crystal
Display (LCD)
Information
Display
T4GB-01-02-001
Monitor Display
Selector (Down)
Monitor Display
Selector (Up)
T5-1-6
Mode Selection
Switch
TROUBLESHOOTING / Diagnosing Procedure
DISPLAY LIST OF MONITOR SERVICE MODE
Display
Order
1
2
3
4
4-1
Description
Model
Clock (24 hour)
Hour Meter
Fuel
Consumption
Amount
Average Fuel Consumption Amount
Monitored Result
Unit
{{{{{{
{{:{{
{{{{{.{ h
{{{{{.{
hh:mm
hour
L/h
{{{{{.{
L/h
Remark
Service Mode
Normal Mode
Normal Mode
Normal Mode
5
5-1
Other Information
Remainder Time when
Hydraulic Oil can be
used
InFo
{{{{{.{
hour
5-2
Remainder Time when
Hydraulic Oil Filter can
be used
{{{{{.{
hour
5-3
Remainder Time when
Transmission Oil can be
used
{{{{{.{
hour
5-4
Remainder Time when
Transmission Oil Filter
can be used
{{{{{.{
hour
5-5
Remainder Time when
Engine Oil can be used
{{{{{.{
hour
5-6
Remainder Time when
Engine Oil Filter can be
used
{{{{{.{
hour
5-7
Remainder Time when
Fuel Filter can be used
{{{{{.{
hour
6
Odometer
{{{{{{
km or mile
7
8
9
Engine Speed
Coolant Temperature
Transmission Oil Temperature
Hydraulic Oil Temperature
Fault Code
{{{{{
{{{{{
{{{{{
min-1
°C
°C
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“4” displayed, Re-set when
pushing the mode selection
switch)
Normal Mode
Normal Mode (Displayed
when pushing the monitor
display selector down) with
“5” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-1” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-2” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-3” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-4” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-5” displayed)
Normal Mode (Displayed
when pushing the monitor
display selector (down) with
“5-6” displayed)
Service Mode (“Mile” is displayed when pushing the
mode selection switch.)
Service Mode
Service Mode
Service Mode
{{{{{
°C
Service Mode
{{{{{{
ERROR
Service Mode
10
11
T5-1-7
TROUBLESHOOTING / Diagnosing Procedure
(Blank)
T5-1-8
TROUBLESHOOTING / Dr. ZX
OUTLINE
Dr. ZX is used for diagnosis of electrical system
including MC (main controller), ECM1, 2 (engine
control module1, 2), ICF (information controller) and
monitor unit.
Dr. ZX is connected to ICF and failure of each
controller and each sensor is displayed as a fault code.
(Self-Diagnostic Result)
Dr. ZX displays the input status of sensors and
switches connected to each controller and the output
status to actuator including solenoid valve from
controller with the machine operated in real time.
(Controller Diagnosis)
T5-2-1
TROUBLESHOOTING / Dr. ZX
Operation
1. Connect Palm (Dr. ZX) to the diagnosing
connector in the cab by using the Hot Sync cable
and connecting harness.
2. Turn the key switch ON or start the engine.
3. When turning Palm ON, the following screen is
displayed on the display of Palm.
1-1. Initial Screen
Select Dr. ZX icon.
Fuse Box
Dr. ZX Connector
1-2. Password Setup Screen (When the password
has unset)
Set the password.
1-3. Service Software Selection Screen
+ Select ZX-3 Mid.
T4GB-05-01-007
1-4. Function Selection Screen
+ Self-Diagnostic Result
+ Select Controller
4. Select Self-Diagnostic Result and operate
according to the instruction under display screen.
Palm
（Dr. ZX）
Hot Sync Cable
Download
Cable for
Portable
Communication
T1V1-05-07-002
T5-2-2
TROUBLESHOOTING / Dr. ZX
Start
Initial Screen
Password Setup Screen
• Input Password
Input
the
former
password (6 characters
or more).
Next time, input the
same password in order
to check and push OK.
When the password has unset
Communication
Error
• Check Communication Harness
• Check Fuse
When the password
has set
Service Software
Selection Screen
Select ZX-3 Mid
Self-Diagnostic
Result Function
Self-Diagnostic
Result of Each
Controller
Select
Function
Record
T1V7-05-03-165
Select Controller
Main
Controller
Engine
Controller
ICF
Controller
Main Menu
• Monitor Display
Main Menu
• Monitor Display
Disp. Record
Password Change
Main Menu
• Information
• Setup
Disp. Record
Select Controller
Password Change
Op. Manual.
Monitor
Controller
C/U
Various Setup
• Data Download
• Save Data Check
Password Change
Retry B
Self-Diagnostic
Result
T5-2-3
Main Menu
• Monitoring
• Various Setup
Password Change
TROUBLESHOOTING / Dr. ZX
Self-Diagnostic Result
The self-diagnostic result of each controller is
displayed.
After starting Dr. ZX, push Self-Diagnostic Result.
Function Selection Screen
T1V7-05-03-001
T1V7-05-03-008
T4GB-05-02-052
Controller Self- Diagnosis Screen
NOTE: Main C/U:
Engine C/U:
Monitor Unit:
Information C/U:
MC
ECM1, 2
Monitor Unit
ICF
NOTE: Self-diagnosis of ICF controller is done on
the next page.
T5-2-4
TROUBLESHOOTING / Dr. ZX
Self-Diagnosis
After starting Dr. ZX,
Self-Diagnostic Result.
Push Fault of ICF Controller. In
case of no faulty, No Fault is
displayed.
push
To the
lower
T1V7-05-03-001
T4GB-05-02-052
T1V7-05-03-008
Controller Self- Diagnosis Screen
By changing the page, the forward or
backward controller is displayed.
Function Selection Screen
By changing the page, the
forward or backward fault Push Retry B and return to
code is displayed.
Controller Self-Diagnosis Screen
after executing Retry B.
Push ESC and return to Controller
Push ESC and Retry B Screen is
Self-Diagnosis Screen directly.
displayed.
Push Details, and Details of the
fault code and Corrective Action
are displayed.
Push ESC and Retry B Screen is
displayed.
Trouble
Retry B
ESC
ESC
T1V7-05-03-003
T1V7-05-03-005
Fault Code Screen
T1V7-05-03-007
Retry B Screen
If the message of Details is
long, push the arrow and
change the screen.
Retry B
ESC
T4GB-05-02-052
Controller Self- Diagnosis Screen
T5-2-5
TROUBLESHOOTING / Dr. ZX
SELECT CONTROLLER
Select the failure-diagnosis controller.
After starting Dr. ZX, push Select Controller.
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
NOTE: Main C/U:
Engine C/U:
Monitor Unit:
Information C/U:
Controller Selection Screen
MC
ECM1, 2
Monitor Unit
ICF
T5-2-6
TROUBLESHOOTING / Dr. ZX
MAIN CONTROLLER
Main Menu
• Monitor Display
Displays the control signals of MC and the input
signals from each switch and sensor.
• Setup
Adjusts target engine idling speed, engine
warming-up speed and so on.
Title Screen
Recorded Data
Displays data recorded in MC by one day by using Dr.
ZX.
Password Change
Changes the password input when setting.
T1V7-05-03-011
Password
Change
Return to Controller
Selection Screen.
Disp. Record
Main Menu Screen
T1V7-05-03-012
Monitor Display
This function is not
available.
Setup
T5-2-7
TROUBLESHOOTING / Dr. ZX
MAIN MENU MONITOR DISPLAY
Dr. ZX displays the input signals from switches and
sensors and the control signals from MC.
MC List of Monitor Item
Item
Required Engine Speed
Hydraulic Fan Target Speed
Actual Engine Speed
Torque Converter Output Speed
Medium Gear Speed
Transmission Output speed
Engine Speed Deviation
Torque Converter Speed Ratio
Travel Speed
Pump Pressure
Pump Displacement Proportional
Valve Output
Hydraulic Drive Fan Proportional
Valve
Ride Control Proportional Valve
Output (Optional)
Pump Displacement Proportional
Valve FB
Hydraulic Drive Fan Proportional
Valve FB
Ride Control Proportional Valve
Output FB (Optional)
Accelerator Pedal
Parking Brake Pressure
Pedal Brake Pressure (Low)
Lift Cylinder Bottom Pressure
(Optional)
Lift Cylinder Rod Pressure (Optional)
Implement Pressure
Boom Angle (Optional)
Key Switch
Ride Control Switch (Optional)
A/C Clutch SW
Fan Reversing SW
FNR SW
Speed Gear SW
Implement FNR SW
Implement FNR Selector SW
USS SW
DSS SW
Speed Gear Hold SW
Selected Speed Gear
Data
Control instruction value of engine speed to ECM1, 2
Control instruction value to fan flow rate control valve
Detected valve of torque converter input speed sensor
Detected valve of torque converter output speed sensor
Detected valve of transmission medium shaft sensor
Detected valve of travel speed sensor
Difference between required engine speed and actual engine
speed
Ratio of the detected value of torque converter output rotation
sensor in that of torque converter input rotation sensor
Value converted the detected value of travel speed sensor into
speed per hour
Detected value to main pump delivery pressure sensor
Control instruction value to pump displacement proportional solenoid valve
Control instruction value to hydraulic drive fan flow rate control
solenoid valve
Control instruction value to ride control solenoid valve
Unit
min-1
min-1
min-1
min-1
min-1
min-1
min-1
No unit
Km/h
MPa
MPa
mA
MPa
Feedback value from pump displacement proportional solenoid
valve
Feedback value from hydraulic drive fan flow rate control solenoid valve
Feedback value from ride control solenoid valve
mA
Output value of accelerator pedal
Detected value of parking brake pressure sensor
Detected value of service brake pressure sensor
Detected value of lift arm cylinder bottom pressure sensor
V
MPa
MPa
MPa
Detected value of lift arm cylinder rod pressure sensor
MPa
Detected value of implement pressure sensor
Output valve of lift arm angle sensor
Key ON signal from key switch to each controller
Continuity status in ride control switch
Continuity status in air conditioner switch
Continuity status in hydraulic drive fan reversing switch
Selected status of forward/reverse lever
Selected status of shift switch
Selected status of forward/reverse switch
Continuity status in forward/reverse selector switch
Continuity status in up-shift switch
Continuity status in down-shift switch
Continuity status in hold switch
Selected speed gear
mA
mA
Actual Speed Gear
Actual speed gear
Boom Height Kickout SW (Optional)
Boom Height Kickout Setup SW
(Optional)
Ground Stop SW (Optional)
Ground Stop Setup SW (Optional)
Continuity status in lift arm auto leveler switch (raise)
MPa
V
ON OFF
ON OFF
ON OFF
ON OFF
N F R Err N
1234
N F R Err N
ON OFF
ON OFF
ON OFF
ON OFF
R4 R3 R2 R1 N
F1 F2 F3 F4
R4 R3 R2 R1 N
F1 F2 F3 F4
ON OFF
Continuity status in lift arm auto leveler switch (raise) set switch
ON
Continuity status in lift arm auto leveler switch (lower)
Continuity status in lift arm auto leveler switch (lower) set switch
ON OFF
ON OFF
T5-2-8
OFF
TROUBLESHOOTING / Dr. ZX
Item
Pump Torque Selection
Data
Selection status of work mode selection switch
Hold Mode
Option FNR Mode
Auto/Manual Selection
Auto Gear Shifting Mode
Enabled/disabled status of hold mode
Enabled/disabled status of forward/reverse switch use mode
Selected status (auto/manual) of travel mode selector switch
Selected status (gear shifting timing) of travel mode selector
switch
Selected status (ON/OFF) of clutch cut-off position switch
Selected status (clutch cut-off position) of clutch cut-off position
switch
Instruction value of forward proportional solenoid valve output
Clutch Cut-Off Switch
Clutch Cut-Off Mode
T/M Clutch Forward Proportional
Valve Output
T/M Clutch Reverse Proportional
Valve Output
T/M Clutch First Gear Proportional Valve Output
T/M Clutch Second Gear Proportional Valve Output
T/M Clutch Third Gear Proportional Valve Output
T/M Clutch Fourth Gear Proportional Valve Output
T/M Clutch Forward Proportional
Valve FB
T/M Clutch Reverse Proportional
Valve FB
T/M Clutch First Gear Proportional Valve FB
T/M Clutch Second Gear Proportional Valve FB
T/M Clutch Third Gear Proportional Valve FB
T/M Clutch Fourth Gear Proportional Valve FB
Hydraulic Drive Fan Reversing
Valve
Implement FNR Operating Light
Back Alarm
Boom Height Kickout (Optional)
Ground Stop System (Optional)
Neutral Signal
Parking brake Light
T/M Warning Light
Ambient Temperature
Hydraulic Oil Temperature
AEB Status (Main Code)
AEB Status (Sub Code)
Learning Step
ON OFF
Low Medium High
mA
Instruction value of reverse proportional solenoid valve output
mA
Instruction value of first gear proportional solenoid valve output
mA
Instruction value of second gear proportional solenoid valve output
Instruction value of third gear proportional solenoid valve output
mA
Instruction value of fourth gear proportional solenoid valve output
mA
Feedback value of forward proportional solenoid valve output
mA
Feedback value of reverse proportional solenoid valve output
mA
Feedback value of first gear proportional solenoid valve output
mA
Feedback value of second gear proportional solenoid valve output
Feedback value of third gear proportional solenoid valve output
mA
Feedback value of fourth gear proportional solenoid valve output
mA
Instruction signal to hydraulic drive fan reversing solenoid valve
ON OFF
Continuity status to enabled indicator in forward/reverse switch
Excited condition of reverse relay in MC
Excited Status of solenoid valve at lift arm raise side in pilot valve
Excited Status of solenoid valve at lift arm lower side in pilot
valve
Forward/reverse neutral signal status
Excited status of parking brake relay 1 and continuity status to
parking brake indicator
Continuity status to transmission warning indicator
Detected value of ambient temperature sensor
Detected value of hydraulic oil temperature sensor
Transmission learning process status code
Transmission learning failure position code
ON
ON
ON
ON
Learning Warning Crash
Learning detail position of transmission learning process status
each code
Learning failure detail position of transmission learning failure
position code
Crash grounds of transmission learning
Angle Sensor Learning Status
Lift arm angle sensor learning status
Learning Warning Step
Unit
LD/Cry
Normal
Power
ON OFF
Acr NotAct
Manual Auto
Low Normal High
T5-2-9
mA
mA
OFF
OFF
OFF
OFF
ON OFF
ON OFF
ON OFF
°C
°C
Normal Other
Enabled Learning
Other
1 2 3
1 2 3
Ky Eng Pbrk Spd
FNR
Not Learn
Finish Failure
TROUBLESHOOTING / Dr. ZX
Monitor Display
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Main C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Controller Selection Screen
Push Start.
Push Monitor Display.
T4GB-05-02-004
Main Controller Screen
To the
lower
T4GB-05-02-070
T1V7-05-03-012
T1V7-05-03-011
Title Screen
Main Menu Screen
Enter Model and Serial No. Screen
Input the model code and serial
No. and push OK. If this procedure
is not done, monitor data cannot
recorded. Push ESC and return to
Main Menu Screen.
Push the item for Monitor Display
and push OK. Refer to T5-2-8, 9 as
for the monitor item. Push ESC
and return to Main Menu Screen.
Push Hold and the monitor are
stopped temporarily. When the monitor
is started again, push Hold again.
Push ESC and return to Display Item
Selection Screen.
T4GB-05-02-008
T4GB-05-02-007
T4GB-05-02-071
Enter Model and Serial No. Screen
Display Item Selection Screen
Monitor Screen
To the next page
T5-2-10
TROUBLESHOOTING / Dr. ZX
Push Rec. No. and the recording
screen for Rec. No. is made.
Push Record.
To the
lower
T4GB-05-02-008
T1V7-05-03-096
Monitor Screen
If Rec. No. has already been
recorded and push Over Write,
data is overwritten. Push ESC and
return to Main Menu Screen.
If Rec. No. has not been recorded
yet and push Write, data is written
to the recording screen. Push ESC
and return to Main Menu Screen.
Select Write Data-Bank Screen
T1V7-05-03-097
Push Comment.
Push ESC and return to Main
Menu Screen.
To the
lower
T4GB-05-02-072
Recording Screen
T4GB-05-02-073
T1V7-05-03-100
Recording Screen
Input weather and person’s name
in change and push OK.
Push OK and the recording screen
(making) is finished.
T4GB-05-02-074
T4GB-05-02-075
Recording Screen (Comment
Input)
T5-2-11
Push Re-Input and return to
Recording
Screen
(Comment
Input).
Push ESC and return to Monitor
Screen.
T4GB-05-02-076
TROUBLESHOOTING / Dr. ZX
SETTING
Target engine idling speed, engine warming-up speed
and so on can be adjusted.
MC List of Parameter Change Item
Item
Unit
Request Speed Ⅰ Calibration
min-1
Warning Up Speed Calibration
min-1
Warming Up Control Deactivation
ON, OFF
Flag
Set Torque Calibration
N⋅m
Data
Adjustment of engine idling speed
Adjustment of engine warming-up speed
Selection (enable/ disable) of engine warming-up control
Adjustment of main pump target torque
MC List of Adjustment Data
Data
Request Speed Ⅰ Calibration
Warning Up Speed Calibration
Warming Up Control Deactivation
Flag
Set Torque Calibration
Adjustment
Minimum Unit
1 min-1
1 min-1
0 to 200
-200 to 200
Adjustment Value
When Delivering
0 min-1
0 min-1
-
ON or OFF
ON
3 N⋅m
-45 to 45
0 N⋅m
Adjustable Range
T5-2-12
Remark
TROUBLESHOOTING/ Dr. ZX
Setting
• Parameter Change
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Main C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Controller Selection Screen
Push Start.
Push Setup.
T4GB-05-02-004
Main Controller Screen
To the
lower
T1V7-05-03-011
T1V7-05-03-012
Title Screen
Main Menu Screen
Input the password and push OK.
Push Cancel and return to Main
Menu Screen.
Push Parameter Change.
Push ESC and return to Main
Menu Screen.
T1V7-05-03-016
Refer to T5-2-12 as for the item of
Parameter Change. Push Engine
Control.
To the
Next Page
T1V7-05-03-022
Setup Password Input Screen
T4GB-05-02-014
Setup Item Selection Screen
T5-2-13
Parameter Change Selection
Screen
T4GB-05-02-015
TROUBLESHOOTING/ Dr. ZX
Parameter Input
Example: Engine Control
Correction
Input Value = Normal Value
Push Request Speed I Calibration..
Target
Speed
I
Input the value and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
Check Adjustment and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
To the
lower
T4GB-05-02-016
Parameter Change Selection
Screen
T4GB-05-02-017
Parameter Input Screen
Push ESC and return to Parameter
Change Selection Screen.
T1V7-05-03-107
T5-2-14
T4GB-05-02-018
TROUBLESHOOTING/ Dr. ZX
Input Value = Current Value
Push Request Speed I Calibration.
Input the value and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
Push Exec. Push ESC and return
to Parameter Change Selection
Screen.
To the
lower
T4GB-05-02-016
Parameter Change Selection
Screen
T4GB-05-02-019
Parameter Input Screen
Push ESC and return to Parameter
Change Selection Screen.
T1V7-05-03-107
T5-2-15
T1V7-05-03-108
TROUBLESHOOTING/ Dr. ZX
Input Value > Maximum Value
(Input Value < Minimum Value)
Push Request Speed I Calibration.
Input the value and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
Push Re-Input and return to
Parameter Input Screen. Push Max
and the maximum value is input.
Push ESC and return to Parameter
Change Selection Screen.
To the
lower
T4GB-05-02-016
Parameter Change Selection
Screen
T4GB-05-02-020
Parameter Input Screen
Push ESC and return to Parameter
Change Selection Screen.
T1V7-05-03-107
T5-2-16
T4GB-05-02-021
TROUBLESHOOTING/ Dr. ZX
When the input value cannot be divided
Example: Pump Control Set Torque Calibration
Push Set Torque Calibration.
Input the value and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
Push Re-Input and return to
Parameter Input Screen. Push A or
B and the value of A or B is input.
Push ESC and return to Parameter
Change Selection Screen.
To the
lower
T4GB-05-02-022
Parameter Change Selection
Screen
T4GB-05-02-023
Parameter Input Screen
Push ESC and return to Parameter
Change Selection Screen.
T1V7-05-03-107
T5-2-17
T4GB-05-02-024
TROUBLESHOOTING/ Dr. ZX
Status Selection
Example: Engine Control Warming Up Control
Deactivation Flag
Push
Warming
Deactivation Flag.
Up
Ctrl
Push OFF and push Exec. Push
ESC and return to Parameter
Change Selection Screen.
Check contents and push Exec.
Push ESC and return to Parameter
Change Selection Screen.
To the
lower
T4GB-05-02-016
Parameter Change Selection
Screen
T4GB-05-02-025
Status Selection Screen
Push ESC and return to Parameter
Change Selection Screen.
T1V7-05-03-107
T5-2-18
T4GB-05-02-026
TROUBLESHOOTING/ Dr. ZX
Recorded Data Display
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Main C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Push and select No. Push
Regeneration and the recorded
data are regenerated.Push DEL
and data of selected No. is
d l t d
Push Start to record.
Push Hold and the monitor are
stopped temporarily. Push Hold
again and restart regeneration.
Push ESC and Recorded Data
Selection Screen is displayed.
T1V7-05-03-124
T1V7-05-03-011
Title Screen
T4GB-05-02-004
Main Controller Screen
Controller Selection Screen
Recorded Data Selection Screen
T5-2-19
Recorded Data Regeneration
Screen
T4GB-05-02-027
TROUBLESHOOTING/ Dr. ZX
PASSWORD CHANGE
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Main C/U.
To the
lower
Function Selection Screen
T1V7-05-03-001
Controller Selection Screen
T4GB-05-02-053
Input the registered password and
push OK.
Push Password.
Main Controller Screen
T4GB-05-02-004
Input the new password and push
OK.
To the
lower
T1V7-05-03-126
T1V7-05-03-011
Title Screen
Input the new password again and
push OK.
Push OK
Screen.
and
return
to
Title
T1V7-05-03-128
T1V7-05-03-169
T5-2-20
T1V7-05-03-127
TROUBLESHOOTING / D r. ZX
ENGINE CONTROLLER
Main Menu
• Monitor Display
Dr. ZX displays the input signals from sensors and
the control signals of ECM1, 2.
• Recorded Data Display
Data recorded in ECM1, 2 is displayed by one day
by using Dr. ZX.
Password
The password can be changed.
T1V7-05-03-079
T5-2-21
TROUBLESHOOTING / D r. ZX
MONITOR DISPLAY
ECM List of Monitor Item
Item
Selecting
Monitoring
Engine Torque
Engine Torque
Actual Engine Speed Actual Engine
(Engine Speed)
Speed
Target Engine Speed
Target Engine
Speed
Coolant
Temperature Coolant
(Engine
Coolant Temperature
Temperature)
(E)
Fuel Temperature
Fuel
Temperature
Engine Oil Temperature Engine
Oil
Temperature
Engine Oil Level
Eng Oil Level
Engine Oil Pressure
Engine
Oil
Pressure
Fuel Flow Rate
Fuel Flow
Instant
Fuel Instant
Fuel
Consumption
Consumption
Average
Fuel Average Fuel
Consumption
Consumption
Boost Pressure
Boost Pressure
Boost Temperature
Boost
Temperature
Total Amount of Fuel Use Total
Used
Fuel
Unit
Data
%
Input signal from ECM2
Input signal from crank shaft angle sensor and TDC
sensor
min
-1
min-1
Input signal from accelerator pedal
°C
Input signal from coolant temperature sensor
°C
Input signal from fuel temperature sensor
°C
%
Input signal from engine oil combination sensor
(temperature, pressure)
Input signal from engine oil level sensor
kPa
Input signal from engine oil pressure sensor
L/h
Input signal from ECM2
Km/L
Input signal from ECM2
Km/L
Input signal from ECM2
kPa
°C
L
Input signal from intake-air
(temperature, pressure)
Input signal from intake-air
(temperature, pressure)
Input signal from ECM2
T5-2-22
combination
sensor
combination
sensor
TROUBLESHOOTING / D r. ZX
(Blank)
T5-2-23
TROUBLESHOOTING / D r. ZX
Monitor Display
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Engine C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Controller Selection Screen
Push Start.
Push Monitor Display.
T4GB-05-02-004
Engine Controller Screen
To the
lower
Title Screen
T4GB-05-02-028
T1V7-05-03-011
Input the model code and serial
No. and push OK. If this procedure
is not done, monitor data cannot
recorded. Push ESC and return to
Main Menu Screen.
T4GB-05-02-077
Main Menu Screen
Enter Model and Serial No. Screen
Push the item for Monitor Display
and push OK. Refer to T5-2-22 as
for the monitor item.
Push ESC and return to Main
Menu Screen.
Push Hold and the monitor are
stopped temporarily. When the
monitor is started again, push Hold
again. Push ESC and return to
Display Item Selection Screen.
Start
recoding.
To the
next page
T4GB-05-02-044
T4GB-05-02-078
Enter Model and Serial No. Screen
Display Item Selection Screen
T5-2-24
T4GB-05-02-045
Monitor Screen
TROUBLESHOOTING / D r. ZX
Push Rec. No. and the recording
screen for Rec. No. is made.
Push Record.
To the
lower
Monitor Screen
T4GB-05-02-045
If Rec. No. has already been
recorded and push Over Write,
data is overwritten.
Push ESC and return to Main
Menu Screen.
T1V7-05-03-134
If Rec. No. has not been recorded
yet and push Write, data is written
to the recording screen.
Push ESC and return to Main
Menu Screen.
Select Write Data-Bank Screen
T1V7-05-03-135
Push Comment.
Push ESC and return to Main
Menu Screen.
To the
lower
T4GB-05-02-079
Recording Screen
T4GB-05-02-030
T4GB-05-02-080
Recording Screen
Input weather and person’s name
in change and push OK.
Push OK and the recording screen
(making) is finished.
T4GB-05-02-081
T4GB-05-02-082
Recording Screen (Comment
Input)
T5-2-25
Push Re-Input and return to
Recording
Screen
(Comment
Input).
Push ESC and return to Main
Menu Screen.
T4GB-05-02-083
TROUBLESHOOTING / D r. ZX
RECORDED DATA DISPLAY
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Engine C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
T4GB-05-02-004
Function Selection Screen
Controller Selection Screen
Engine Controller Screen
Push Disp. Record.
Push and select No. Push
Regeneration and the recorded
data is regenerated. Push DEL and
data of selected No. is deleted.
Push ESC and return to Title
Screen.
Push Hold and the monitor is
stopped temporarily
When the monitor is started again,
push Hold again.
Push ESC and return to Recored
Data Selection Screen.
T4GB-05-02-051
T1V7-05-03-124
T1V7-05-03-011
Title Screen
Recorded Data Selection Screen
T5-2-26
Recorded Data Regeneration
Screen
TROUBLESHOOTING / D r. ZX
PASSWORD CHANGE
After starting Dr. ZX, push Select
Controller.
Push Engine C/U.
Push OK.
To the
lower
T1V7-05-03-001
T4GB-05-02-053
T4GB-05-02-004
Function Selection Screen
Controller Selection Screen
Engine Controller Screen
Push Password.
Input the registered password and
push OK.
Input the new password and push
OK.
To the
lower
T1V7-05-03-126
T1V7-05-03-011
Title Screen
Input the new password again and
push OK.
Push OK
Screen.
and
return
to
Title
T1V7-05-03-128
T1V7-05-03-169
T5-2-27
T1V7-05-03-127
TROUBLESHOOTING / D r. ZX
(Blank)
T5-2-28
TROUBLESHOOTING / Dr. ZX
ICF CONTROLLER
Main Menu
• Information C/U Various Setup
Initialization of information C/U, setting of model,
serial No. and time, and initialization of control
data can be done.
• Data Download
Daily report data, frequency distribution data, total
operating hours, alarm and fault code, which are
recorded in ICF, can be downloaded to Dr. ZX.
• Save Data Check
Daily report data, frequency distribution data, total
operating hours, alarm and fault code, which are
saved in ICF, can be checked by using Dr. ZX.
Password
The password can be changed.
T1V7-05-03-166
T5-2-29
TROUBLESHOOTING / Dr. ZX
INFORMATION C/U VARIOUS SETUP
ICF List of Controller Data Setting Item
Item
Information C/U: Initialize
Enter Model and Serial No.
Range of Data
Model
Serial No.
Enter Date and Time
YY
MM
DD
HH
MM
Date
Time
Control Data: Initialize
Satellite Terminal: Initialize
Satellite Terminal No. Confirmation
Communicating State Check
ICF < = > Satellite
Terminal
Satellite Terminal
Connect
Comm.
Power
Comm.
Rod Aerial
GPS Aerial
Wave State
Un-Transmit Data Number
Last Transmitting Time
Enter Satellite Comm.
Start/Stop
T5-2-30
Initialize/ESC
ASCII (4 characters) 0 to 9, A to Z
000000 to 999999
2000 to 2100
1 to 12
1 to 31
0 to 23
0 to 59
Initialize/ESC
DEL/ESC
12 digits: 0 to 9, A to Z
Conn/UnConn
OK/NG
ON/OFF
Enable/Stop
OK/NG
OK/NG
ON/OFF
0～99
YYYY/MM/DD hh: mm: ss
Start/Stop
TROUBLESHOOTING / Dr. ZX
INFORMATION C/U: INITIALIZE
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
Function Selection Screen
T1V7-05-03-001
Controller Selection Screen
Push Information
Setup.
Push Start.
C/U:
T4GB-05-02-053
Various
ICF Controller Screen
T4GB-05-02-036
Push Information C/U: Initialize.
To the
lower
Title Screen
T1V7-05-03-025
Push Init and the controller
operating data is initialied. Push
ESC and return to Information C/U:
Various Setup Screen.
Main Menu Screen
T1V7-05-03-026
T1V7-05-03-027
Information C/U: Various Setup
Screen
Push OK and return to Information
C/U: Various Setup Screen.
Push ESC and return to Main
Menu Screen.
Init
ESC
T1V7-05-03-029
T1V7-05-03-028
T1V7-05-03-027
Information C/U: Various Setup
Screen
Information C/U: Initialize Screen
T5-2-31
TROUBLESHOOTING / Dr. ZX
ENTER MODEL AND SERIAL No.
After starting Dr. ZX, push Select
Controller.
Push Information C/U.
Push OK.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
T4GB-05-02-036
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Start.
Push Information
Setup.
Push Enter Model and Serial No.
C/U:
Various
To the
lower
T1V7-05-03-026
T1V7-05-03-025
Title Screen
Main Menu Screen
Push Exec and model and serial
No. can be input.
Push ESC and return to
Information C/U: Various Setup
Screen.
Push OK after inputting model and
serial No. and return to Enter
Model and Serial No. Screen.
Push ESC and return to
Information C/U: Various Setup
Screen.
T1V7-05-03-027
Information C/U: Various Setup
Screen
Push ESC and return to Main
Menu Screen.
ESC
Exec
ESC
OK
T4GB-05-02-084
T4GB-05-02-085
T1V7-05-03-027
Information C/U: Various Setup
Screen
Enter Model and Serial No. Screen
T5-2-32
TROUBLESHOOTING / Dr. ZX
ENTER DATE AND TIME
After starting Dr. ZX, push Select
Controller.
Push Information C/U.
Push OK.
To the
lower
Function Selection Screen
T4GB-05-02-053
T1V7-05-03-001
Controller Selection Screen
Push Information
Setup.
Push Start.
C/U:
Various
ICF Controller Screen
T4GB-05-02-036
Push Enter Date and Time.
To the
lower
T1V7-05-03-026
T1V7-05-03-025
Title Screen
T1V7-05-03-027
Information C/U: Various Setup
Screen
Main Menu Screen
Push Set and the focused item is
YY. Push ESC and return to
Information C/U: Various Setup
Screen.
YY, MM, DD, HH and MM
The focused item is displayed reversely.
At first, the focused item is YY.
－
YY, MM, DD, HH and MM
Move the focused item.
No repeat input.
T1V7-05-03-032
Enter Date and Time Screen
＋
YY, MM, DD, HH and MM
Value of the focused item is increased or
decreased one by one.
In case value is beyond maximum one: Change
value into the minimum one
In case value is below minimum one: Change
value into the maximum one
No repeat input.
T5-2-33
TROUBLESHOOTING / Dr. ZX
CONTROL DATA: INITIALIZE
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
Function Selection Screen
T4GB-05-02-053
T1V7-05-03-001
Controller Selection Screen
Push Information
Setup.
Push Start.
C/U:
T4GB-05-02-036
ICF Controller Screen
Various
Push Control Data: Initialize.
To the
lower
Title Screen
T1V7-05-03-025
Push Init and the controller control
data is initialied. Push ESC and
return to Information C/U: Various
Setup Screen.
T1V7-05-03-026
Main Menu Screen
Information C/U: Various Setup
Screen
Push OK and return to Information
C/U: Various Setup Screen.
Push ESC and return to Main
Menu Screen.
T1V7-05-03-027
Init
ESC
T1V7-05-03-034
T1V7-05-03-033
T1V7-05-03-027
Information C/U: Various Setup
Screen
Control Data: Initialize Screen
T5-2-34
TROUBLESHOOTING / Dr. ZX
SATELLITE TERMINAL: INITIALIZE
After starting Dr. ZX, push Select
Controller.
Push Information C/U.
Push OK.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Push Start.
T4GB-05-02-036
Controller Selection Screen
ICF Controller Screen
Push Information
Setup.
Push T and move to the next
screen of Information C/U: Various
Setup Screen. Push Satellite
Terminal: Initialize.
C/U:
Various
To the
lower
T1V7-05-03-026
T1V7-05-03-025
Title Screen
Main Menu Screen
Push Exec.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
T1V7-05-03-035
Information C/U: Various Setup
Screen
Exec
ESC
T1V7-05-03-145
T1V7-05-03-036
T5-2-35
Information C/U: Various Setup
Screen
T1V7-05-03-035
TROUBLESHOOTING / Dr. ZX
SATELLITE TERMINAL No. CONFIRMATION
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Push Start.
T4GB-05-02-036
Controller Selection Screen
ICF Controller Screen
Push Information
Setup.
Push T and move to the next
screen of Information C/U: Various
Setup Screen. Push Satellite
Terminal No. Confirmation.
C/U:
Various
To the
lower
T1V7-05-03-026
T1V7-05-03-025
Main Menu Screen
Title Screen
Confirm serial No. (12 digits). Push
ESC and return to Information C/U:
Various Setup Screen.
T1V7-05-03-035
T1V7-05-03-037
T5-2-36
T1V7-05-03-035
Information C/U: Various Setup
Screen
TROUBLESHOOTING / Dr. ZX
COMMUNICATING STATE CHECK
After starting Dr. ZX, push Select
Controller.
Push Information C/U.
Push OK.
To the
lower
T1V7-05-03-001
Function Selection Screen
Push Start.
T4GB-05-02-053
Controller Selection Screen
ICF Controller Screen
Push Information
Setup.
Push T and move to the next
screen of Information C/U: Various
Setup
Screen.
Push
Communicating State Check.
C/U:
Various
T4GB-05-02-036
To the
lower
T1V7-05-03-026
T1V7-05-03-025
Title Screen
Main Menu Screen
Check communicating state.
Unconn: Faulty harness
NG: Faulty harness for Comm.
OFF: Faulty harness, Faulty controller
Stop: Enter Satellite Comm. Start/Stop
Push ESC and return to Information
C/U: Various Setup Screen.
Push T and move to the next
screen. Check communicating
state of Rod Aerial and GPS Aerial.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
T1V7-05-03-035
Information C/U: Various Setup
Screen
Push ESC and return to Main
Menu Screen.
ESC
T1V7-05-03-143
T1V7-05-03-142
T1V7-05-03-035
When electrical wave of the satellite is caught,
the items are turned into OK.
Check the enclosed state.
IMPORTANT: Check this with the key of machine
ON in outdoor. According to state
of electrical wave, it may take a
little longer time.
T5-2-37
TROUBLESHOOTING / Dr. ZX
ENTER SATELLITE COMM. START / STOP
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
T1V7-05-03-001
Function Selection Screen
Push Start.
T4GB-05-02-053
Controller Selection Screen
ICF Controller Screen
Push Information
Setup.
Push T and move to the next
screen of Information C/U: Various
Setup Screen. Push Enter Satellite
Comm. Start/Stop.
C/U:
Various
T4GB-05-02-036
To the
lower
Title Screen
T1V7-05-03-026
T1V7-05-03-025
When starting Satellite Comm., push
Start and push Exec. When stopping
Satellite Comm., push Stop and push
Exec.
Push ESC and return to Information
C/U: Various Setup Screen.
T1V7-05-03-035
Main Menu Screen
Information C/U: Various Setup
Screen
Push OK and return to Information
C/U: Various Setup Screen.
Push ESC and return to Main
Menu Screen.
Exec
ESC
T1V7-05-03-147
T1V7-05-03-146
T5-2-38
Information C/U: Various Setup
Screen
T1V7-05-03-035
TROUBLESHOOTING / Dr. ZX
DATA DOWNLOAD
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
Function Selection Screen
T1V7-05-03-001
Push Start.
Controller Selection Screen
T4GB-05-02-053
ICF Controller Screen
T4GB-05-02-036
While downloading data, Download
Screen is displayed.
Push Data Download.
To the
lower
Title Screen
T1V7-05-03-025
When downloading is completed
normally, Normal End Screen is
displayed. Push OK and return to
Main Menu Screen.
Main Menu Screen
If pushing Cancel on Data
Download Screen, Alarm Screen is
displayed. Push OK and return to
Main Menu Screen.
Data Download Screen
Alarm Screen
T1V7-05-03-026
Main Menu Screen
T5-2-39
T1V7-05-03-038
Push ESC and return to Title
Screen.
T1V7-05-03-148
T1V7-05-03-039
Normal End Screen
T1V7-05-03-026
TROUBLESHOOTING / Dr. ZX
SAVE DATA CHECK
After starting Dr. ZX, push Select
Controller.
Push Information C/U.
Push OK.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Push Start.
ICF Controller Screen
Push Save Data Check.
Data saved in ICF is displayed.
Push OK and return to Main Menu
Screen.
T4GB-05-02-086
T1V7-05-03-026
T1V7-05-03-025
Title Screen
T4GB-05-02-036
Controller Selection Screen
Main Menu Screen
T5-2-40
Save Data Check Screen
TROUBLESHOOTING / Dr. ZX
PASSWORD CHANGE
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Information C/U.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Password.
Input the registered password and
push OK.
Input the new password and push
OK.
T4GB-05-02-036
To the
lower
T1V7-05-03-126
T1V7-05-03-025
Title Screen
Input the new password again and
push OK.
Push OK
Screen.
and
return
to
Title
T1V7-05-03-128
T1V7-05-03-169
T5-2-41
T1V7-05-03-127
TROUBLESHOOTING / Dr. ZX
(Blank)
T5-2-42
TROUBLESHOOTING / Dr. ZX
MONITOR UNIT
Main Menu
• Monitoring
Dr. ZX displays the input signals from each sensor
and switch.
• Various Settings
Dr. ZX can set inner hour meter synchronization.
Password
The password can be changed.
T4GB-05-02-039
T5-2-43
TROUBLESHOOTING / Dr. ZX
MONITORING
List of Monitoring Item
Item
Data
Radiator Coolant Temperature Signal to coolant temperature gauge
Fuel Level
Signal to fuel gauge
T/M Torque Converter Oil Signal to transmission oil temperature gauge
Temperature
Steering Pressure
Continuity status in emergency steering pressure switch
Brake Oil Level Switch of Continuity status to brake oil level indicator
Service Brake
Unit
°C
%
°C
ON OFF
ON OFF
Emergency Steering Pump Continuity status in emergency steering pump delivery
Pressure Switch
pressure switch
ON OFF
Service Brake Pressure
Detected value in brake primary pressure sensor
Overheat Switch
Continuity status to overheat indicator
Engine Oil Pressure Switch
Continuity status to engine oil pressure indicator
Air Filter Restriction
Continuity status to air filter restriction indicator
Heated
Window
Switch Continuity status in heated window switch (optional)
(Optional)
MPa
ON OFF
ON OFF
ON OFF
ON OFF
Emergency
Steering Continuity status in emergency steering check switch
Operation Check Switch
Front Wiper Switch
Continuity status in front wiper switch
Engine Warning Switch
Continuity status to engine warning indicator
Engine STOP Switch
Continuity status to stop indicator
ON OFF
Switch 1 OFF, switch 2 OFF: ZW220/250
Model Selector Switch 1
Switch 1 ON, switch 2 OFF: ZW310
Model Selector Switch 2
Glow Switch
Continuity status to glow signal
T/M Warning Switch
Continuity status to transmission warning indicator
Buzzer Output
Continuity status to buzzer
Load Dump Relay Output
Excited status in load dump relay
Emergency Steering Relay Excited status in emergency steering relay
Output
Front Wiper Relay Output
Excited status in front wiper relay
Heated Window Relay Output Excited status in heated window relay
Parking Brake Signal Output
Sending status of parking brake operating signal to TCU
Parking
Brake
Pressure Continuity status in parking brake pressure switch
Switch
Neutral Signal
Excited status in neutral relay
Axle Oil Temperature
Detected value in axle oil temperature sensor
T5-2-44
ON
ON
ON
ON
ON
ON
ON
ON
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
OFF
OFF
ON OFF
°C
TROUBLESHOOTING / Dr. ZX
Monitoring
After starting Dr. ZX, push Select
Controller.
Push OK.
Push Monitor Unit.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
Function Selection Screen
Push Start.
T4GB-05-02-040
Controller Selection Screen
Monitor Controller Screen
Push Monitoring.
Push item for monitoring and push
OK. Refer to T5-2-44 as for the
monitoring item.
Push ESC and return to Main Menu
Screen.
To the
lower
Title Screen
T1V7-05-03-025
T1V7-05-03-042
Main Menu Screen
When pushing Hold, the monitor is
stopped temporarily.
When re-starting the monitor, push
Hold again. Push ESC and return
to Monitoring Item Selection
Screen.
T4GB-05-02-042
Monitoring Screen
T5-2-45
T4GB-05-02-041
Monitoring Item Selection Screen
TROUBLESHOOTING / Dr. ZX
VARIOUS SETTINGS
Monitor Unit List of Setup Item
Item
Internal Hour Meter Sync.
Data
Synchronization of hour meter data in both monitor unit and ICF
MC List of Adjustment Data
Data
Internal Hour Meter Sync.
Adjustment
Minimum Unit
-
Adjustable Range
T5-2-46
ON only
Adjustment
Minimum Unit
-
Remark
TROUBLESHOOTING / Dr. ZX
INTERNAL
HOUR
SYNCHRONIZATION
After starting Dr. ZX, push Select
Controller.
METER
Push Monitor Unit.
Push OK.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
T4GB-05-02-040
Function Selection Screen
Controller Selection Screen
Monitor Controller Screen
Push Start.
Push Various setting.
Push Internal Hour Meter Sync.
To the
lower
T1V7-05-03-042
T1V7-05-03-025
Title Screen
Main Menu Screen
Push Sync. Push ESC and return
to the former screen.
Push ESC and return to Various
Setup Item Screen.
T1V7-05-03-086
T1V7-05-03-085
Maintenance Set Item Screen
T5-2-47
T4GB-05-02-043
Various Setup Item Screen
TROUBLESHOOTING / Dr. ZX
PASSWORD CHANGE
After starting Dr. ZX, push Select
Controller.
Push Monitor Unit.
Push OK.
To the
lower
T4GB-05-02-053
T1V7-05-03-001
T4GB-05-02-040
Function Selection Screen
Controller Selection Screen
Monitor Controller Screen
Push Password.
Input the registered password and
push OK.
Input the new password and push
OK.
To the
lower
T1V7-05-03-126
T1V7-05-03-025
Title Screen
Main Menu Screen
Input the new password again and
push OK.
Push OK
Screen.
and
return
to
Title
T1V7-05-03-128
T1V7-05-03-169
.
T5-2-48
T1V7-05-03-127
TROUBLESHOOTING / e-Wheel
OUTLINE
ICF (Information Controller) saves the input signals
from various sensors and switches of the machine as
data by using CAN bus line from each controller.
Various input signals are recorded as “list of daily
report data”, “list of frequency distribution data”, “list of
total operating hours”, “list of alarm” and “list of failure”
in ICF.
The recorded data is downloaded to the personal
computer and is uploaded to the center server via
LAN, so that the data can be used as “e-Service”.
The machine equipped with the optional satellite
communication terminal can send the data to center
server by using satellite communication. (As for the
satellite communication system, refer to T5-3-24.)
T5-3-1
TROUBLESHOOTING / e-Wheel
LIST OF DAILY REPORT DATA
Item
1.
Date
2.
Fuel Level
3.
4.
5.
6.
7.
Fuel Usage Amount
Machine Hour Meter
Engine Operating Hours
Operating Distance
Manual Transmission Operating Hours
8.
Automatic Transmission Operating Hours
9.
L Mode Operating Hours
Details
Date of daily report data
The value of the final remained fuel during a day when
the engine stops
The value of fuel used during a day
Hour meter cumulative hours
Total engine operating hours during a day
Traveling distance during a day
Total manual transmission operating hours during a day
Total automatic transmission operating hours during a
day
Total hours operating L mode of work mode selection
switch during a day
Total hours operating N mode of work mode selection
switch during a day
Total hours operating P mode of work mode selection
switch during a day
The highest radiator coolant temperature during a day
The highest hydraulic oil temperature during a day
The highest fuel temperature during a day
The highest torque converter oil temperature during a
day
Engine operating hour distribution during a day
(Operating hours are recorded only when alternator
output signal is continuously delivered for more than 10
minutes.)
10. N mode Operating Hours
11. P mode Operating Hours
12. Radiator Coolant Temperature
13. Hydraulic Oil Temperature
14. Fuel Temperature
15. Torque Converter Oil Temperature
16. Engine Operating Hour Distribution
NOTE: The daily operation in this table is
equivalent to the hours between 0:00 and
23:59:59 counted by the ICX built-in clock.
In case the engine is kept operated
beyond 0:00, such data are recorded as
those for the following day.
T5-3-2
TROUBLESHOOTING / e-Wheel
LIST OF FREQUENCY DISTRIBUTION DATA
1.
2.
3.
4.
5.
6.
Item
Fuel Temperature Distribution
Pump Load Distribution
Travel Load Distribution
Radiator Coolant Temperature Distribution
Hydraulic Oil Temperature Distribution
Torque converter oil Temperature Distribution
7.
8.
Brake Pressure Distribution
Radiator Coolant Temperature - Intake Air
Temperature Distribution
9. Hydraulic Oil Temperature - Intake Air
Temperature
10. Torque Converter Oil Temperature - Intake
Air Temperature Distribution i
11. Radiator Coolant Temperature/Intake Air
Temperature
12. Hydraulic
Oil
Temperature/Intake
Air
Temperature
13. Torque Converter Oil Temperature / Intake Air
Temperature
14. Manual Transmission Speed Distribution
15. Automatic Transmission Speed Distribution
16. Engine Load Rate
Details
Frequency distribution of fuel temperature
Frequency distribution of main pump delivery pressure
Frequency distribution of travel torque
Frequency distribution of coolant temperature
Frequency distribution of hydraulic oil temperature
Frequency distribution of torque converter oil
temperature
Frequency distribution of secondary brake pressure
Frequency distribution on temperature in which intake air
temperature is pulled from coolant temperature
Frequency distribution on temperature in which intake air
temperature is pulled from hydraulic oil temperature
Frequency distribution on temperature in which intake air
temperature is pulled from torque converter oil
temperature
Frequency distribution of coolant temperature and intake
air temperature
Frequency distribution of hydraulic oil temperature and
intake air temperature
Frequency distribution of torque converter oil
temperature and intake air temperature
Frequency distribution of speed in manual transmission
Frequency distribution of speed in automatic
transmission
Frequency distribution of engine spood and engine
torque
IMPORTANT: As the machine (ZW310) is not
equipped
with
the
intake-air
temperature sensor, the output data
on items 8 and 11, 9 and 12, 10 and
13 are equal to items 4, 5, 6
respectively.
T5-3-3
TROUBLESHOOTING / e-Wheel
LIST OF TOTAL OPERATING HOURS
1.
2.
3.
4.
5.
6.
7.
Item
Hour Meter (ICF)
Hour Meter (Monitor Unit)
Engine Operating Hour
Traveling Distance
Manual Transmission Operating Hours
Automatic Transmission Operating Hours
L mode Operating Hours
8.
N mode Operating Hours
9.
P mode Operating Hours
Details
Hour meter’s value accumulated inside ICF
Hour meter’s value accumulated in monitor unit
Total engine operating hours
Total traveling Distance
Total manual transmission operating hours
Total automatic transmission operating hours
Total hours operating L mode of work mode selection
switch
Total hours operating N mode of work mode selection
switch
Total hours operating P mode of work mode selection
switch
T5-3-4
TROUBLESHOOTING / e-Wheel
LIST OF ALARM
1.
2.
3.
4.
5.
6.
7.
8.
9.
Item
Overheat Alarm
Engine Warning Alarm
Engine Oil Pressure Alarm
Alternator Indicator Alarm
Air Filter Restriction Alarm
Water Separator Alarm
Service Brake Oil Level Alarm
Service Brake Oil Pressure Alarm
Emergency Steering Operation Alarm
Details
Date when the overheat indicator lights
Date when the engine warning indicator lights
Date when the engine oil pressure indicator lights
Date when the alternator indicator lights
Date when the air filter restriction indicator lights
Date when the water separator indicator lights
Date when the service brake oil level indicator lights
Date when the service brake oil pressure indicator lights
Date when the emergency steering operation indicator
lights
Date when the steering oil pressure indicator lights
Date when the transmission oil temperature indicator
lights
Date when the hydraulic oil temperature indicator lights
Date when the transmission filter restriction indicator
lights
Date when the transmission failure indicator lights
10. Steering Oil Pressure Alarm
Transmission Oil Temperature Alarm
11.
12. Hydraulic Oil Temperature Alarm
Transmission Filter Restriction Alarm
13.
14. Transmission Failure Alarm
NOTE: When the alarm above is recorded, check
each item.
If the monitor is faulty, refer to
Troubleshooting C.
T5-3-5
TROUBLESHOOTING / e-Wheel
LIST OF FAILURE
When the fault code occurs, ICF records the fault
code and the date.
Use the list of failure when the malfunction, which is
difficult to identify, occurs as the remedy information.
Refer to Troubleshooting A.
If the machine is operated properly with the fault code
recorded, the machine can continue to be operated.
T5-3-6
TROUBLESHOOTING / e-Wheel
HOW TO DOWNLOAD AND UPLOAD DATA
OF ICF
After the data saved in ICF is downloaded to Dr. ZX, is
uploaded to the personal Computer, and is uploaded
to the center server by using LAN, the data can be
used as “e-Service”.
Dr.ZX Connector
How to Download Data from Machine to Dr. ZX
1. Connect Dr. ZX to the machine by using the Hot
Sync cable and download cable for portable
communication system.
2. Turn Dr. ZX ON and start downloading the data.
(Refer to the next page.)
T4GB-05-01-007
Dr. ZX
(Palm)
Hot Sync
Cable
Download Cable
for Portable
Communication
System
T1V1-05-07-002
T5-3-7
TROUBLESHOOTING / e-Wheel
Data Download
After starting Dr. ZX, push Select
Controller.
Select Function
+
Select failure-diagnosis
controller
Self-Diagnostic Result
+
Push OK.
Push ICF Controller.
Select Controller
+
Engine Controller
+
Main Controller
・ ICF
controller Ver.: XXYY
・ Satellite terminal Controller
Ver.: XXYY
+
Monitor Controller
Is it correct?
+
ICF Controller
ESC
ESC
OK
ESC
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Start.
Push Date Download.
While downloading data, Download
Screen is displayed.
Select Item
Data Download
Password
Dr. ZX SerVice Soft
(C)Hitachi Construction
Machinery Co., ltd
+
Information C/U: Various
Setup
+
Data Download
+
Save Data Check
Downloading.
Do not turn off the Palm or
disconnect the download
cable.
27%
+
Op. Manual
Start
Back
ESC
Cancel
Title Screen
Main Menu Screen
Data Download Screen
When downloading is completed
normally, Normal End Screen is
displayed.
Push OK and return to Main Menu
Screen.
If pushing Cancel on Data
Download Screen, Alarm Screen is
displayed. Push OK and return to
Main Menu Screen.
Push ESC and return to Title
Screen.
Select Item
i
Initialization has been
completed.
The
download
is
completed.
CAUTION
Initialization has been
The completed.
download has been
interrupted.
You may disconnect the
download cable.
No
data
has
been
transferred to the Dr. ZX
OK
Normal End Screen
+
Information C/U: Various
Setup
+
Data Download
+
Save Data Check
+
OK
ESC
Main Menu Screen
Alarm Screen
T5-3-8
To the
lower
To the
lower
TROUBLESHOOTING / e-Wheel
How to Upload Data from Dr. ZX (Palm) to
Personal Computer
1. Set Dr. ZX (Palm) to the cradle. Connect the USB
cable to the personal computer.
2. Push the Hot Sync button.
NOTE: When pushing the Hot Sync button and
uploading the data to the personal
computer, the Palm Desktop software
attached with Dr. ZX (Palm) need to be
installed.
Dr. ZX
(Palm)
Cradle
Hot Sync
Button
T178-05-07-033
T5-3-9
TROUBLESHOOTING / e-Wheel
VARIOUS SETUP OF ICF AND SATELLITE
COMMUNICATION TERMINAL BY USING
Dr. ZX
Before starting satellite communication, installing the
satellite communication terminal and replacing ICF,
perform the following procedures by using Dr. ZX.
ICF Setup Procedures
Start Dr. ZX
1.1
Select Information Controller
1.2
Select Information C/U: Various Setup
1.3
Enter Date and Time
1.4
Enter Model and Serial No.
1.5
Information C/U: Initialize
Communication
1.6
Satellite Terminal: Initialize
1.7
Satellite Terminal Serial No. Check
1.8
Satellite Terminal, Communicating State Check
No Communication
2. Self-Diagnosing
T5-3-10
TROUBLESHOOTING / e-Wheel
1.1 Select Information Controller
1.2 Select Information C/U: Various Setup
1.1 Select Information Controller
After starting Dr. ZX, push Select
Controller.
Push ICF Controller.
Select Function
Select failure-diagnosis
controller
+
Self-Diagnostic Result
+
Select Controller
Push OK.
+
Engine Controller
+
Main Controller
・ ICF
Controller Ver.: XXYY
・ Satellite Terminal
Controller Ver.: XXYY
+
Monitor Controller
Is it correct?
+
ICF Controller
ESC
Function Selection Screen
ESC
Controller Selection Screen
OK
To the
lower
ESC
ICF Controller Screen
1.2 Select Information C/U: Various Setup
Push Information
Setup.
Push Start.
C/U:
Various
Select Item
Password
+
Dr. ZX SerVice Soft
(C)Hitachi Construction
Machinery Co., ltd
+
+
Select Item
Information C/U: Various
Setup
Data Download
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Save Data Check
+
+
Enter Date and Time
Control Data: Initialize
Op. Manual
Start
Title Screen
Back
ESC
Main Menu Screen
T5-3-11
ESC
Information C/U: Various Setup
Screen
TROUBLESHOOTING / e-Wheel
1.3 Enter Date and Time
Push Enter Date and Time.
Push ESC and return to Main
Menu Screen.
Push Set and the focused item is
YY.
Push ESC and return to Information
C/U: Various Setup Screen.
Enter Date and Time
Select Item
+
Information C/U: Initialize
YY 2004 MM
01
+
HH
01
01
+
Enter Model and Serial
No.
Enter Date and Time
+
Control Data: Initialize
MM
DD
－
Set
ESC
Information C/U: Various Setup
Screen
01
＋
ESC
YY, MM, DD, HH and MM
The focused item is displayed reversely.
At first, the focused item is YY.
YY, MM, DD, HH and MM
Move the focused item.
No repeat input.
Enter Date and Time Screen
－
YY, MM, DD, HH and MM
Value of the focused item is increased or
decreased one by one.
In case value is beyond maximum one: Change
value into the minimum one
In case value is below minimum one: Change
value into the maximum one
No repeat input.
Select Item
+
Information C/U: Various
Setup
+
Data Download
+
Save Data Check
＋
+
ESC
Main Menu Screen
T5-3-12
TROUBLESHOOTING / e-Wheel
1.4 Enter Model and Serial No.
Push Enter Model and Serial No.
Select Item
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: Initialize
To the
lower
ESC
Information C/U: Various Setup
Screen
After inputting model and serial No.,
push OK and return to Enter Model
and Serial No. Screen.
Push ESC and return to Information
C/U: Various Setup Screen.
Push Exec, and model and serial
No. can be input.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Enter Model and Serial No.
Model
Enter Model and Serial No.
04GB
Select Item
Model |
Exec
Serial No. 000001
Exec
Push ESC and return to Main
Menu Screen.
ESC
ESC
Ex. Mach.No.(HCM4GB00P00
0001) Model(04GB)
Serial No.
Ex. Mach.No.(HCM4GB00P00
0001) Serial No.(000001)
OK
ESC
ESC
OK
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: Initialize
ESC
Information C/U: Various Setup
Screen
Enter Model and Serial No.
T5-3-13
TROUBLESHOOTING / e-Wheel
1.5 Information C/U: Initialize
Push Information C/U: Initialize.
Select Item
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: Initialize
To the
lower
ESC
Information C/U: Various Setup
Screen
Push Init and the controller
operating data is initialized.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
Information C/U: Initialize
Select Item
Is operation data erased?
Init
i
Initialization has been
completed.
Initialization has been
completed.
ESC
Init
ESC
Push ESC and return to Main
Menu Screen.
OK
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: initialize
ESC
Information C/U: Various Setup
Screen
Information C/U: Initialize Screen
T5-3-14
TROUBLESHOOTING / e-Wheel
1.6 Satellite Terminal: Initialize
Display the next screen of
Information C/U: Various Setup
Screen.
Push Satellite Terminal: Initialize.
Push ESC and return to Main
Menu Screen.
Push Exec.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Select Item
Select Item
Satellite Terminal: Initialize
+ Information C/U: Initialize
+
+ Enter Model and Serial
No.
+
+ Enter Date and Time
+
+ Control Data: Initialize
+
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
ESC
Information C/U: Various Setup
Screen
ESC
Is Un-Transmit data erased?
Exec
ESC
Next Screen of Information C/U:
Various Setup Screen
Satellite Terminal: Initialize
Select Item
Select Item
Push OK and return to Information
C/U: Various Setup Screen.
Satellite Terminal: Initialize
+
Un-Transmit data is erased.
+
+
+
OK
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
+
Information C/U: Various
Setup
+
Data Download
+
Save Data Check
+
ESC
Information C/U: Various Setup
Screen
T5-3-15
ESC
Main Menu Screen
To the
lower
TROUBLESHOOTING / e-Wheel
1.7 Satellite Terminal Serial No. Check
Push
Satellite
Terminal
No.
Confirmation.
Push ESC and return to Main
Menu Screen.
Confirm serial no. (12 digits). Push
ESC and return to Information C/U:
Various Setup Screen.
Select Item
Satellite Terminal No.
Confirmation
+
+
+
+
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
Select Item
+
+
Serial No. 8GBDA701862
+
+
ESC
ESC
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
ESC
Information C/U: Various Setup
Screen
Information C/U: Various Setup
Screen
Select Item
+
Information C/U: Various
Setup
+
Data Download
+
Save Data Check
+
ESC
Main Menu Screen
T5-3-16
TROUBLESHOOTING / e-Wheel
1.8 Satellite
Check
Terminal,
Communicating State
Push
Communicating
State
Check.
Push ESC and return to Main
Menu Screen.
Check communicating state.
Select Item
Communicating State Check
+
+
+
+
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
Check the enclosed state.
ICF⇔Satellite Terminal
・ Conn
UnCon
UnCon
・ Comm.
OK
NG
Satellite Terminal
・ Power
ON
OFF
・ Comm.
Enable
Stop
ESC
ESC
Information C/U: Various Setup
Screen
Communicating State Check
Rod Aerial
OK
NG
GPS Aerial
OK
NG
Wave State
ON
OFF
Un Transmit Data Number
0
Last Transmitting Time
UnCon: Faulty harness
NG: Faulty harness for Comm.
OFF: Faulty harness, Faulty controller
Stop: 1.9 Enter Satellite Comm. Start/Stop is
performed.
When electrical wave of the satellite is caught,
the items are turned into OK.
IMPORTANT: Check this with the key of
machine ON in outdoor.
According to state of electrical
wave, it may take a little longer
time.
2004/07/01 13：50：00
ESC
Select Item
Select Item
+
Information C/U: Various
Setup
+
+
Data Download
+
+
Save Data Check
+
+
+
ESC
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
ESC
Information C/U: Various Setup
Screen
Main Menu Screen
T5-3-17
TROUBLESHOOTING / e-Wheel
1.9 Enter Satellite Comm. Start/Stop
Push ▼ and move to the next
screen of Information C/U: Various
Setup Screen.
Push Enter Satellite Comm.
Start/Stop.
Select Item
+
+
+
+
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
To the
lower
ESC
Information C/U: Various Setup
Screen
In normal, Start is selected. When
stopping Satellite Comm., due to
some reasons, push Stop and
push Exec.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
Enter Satellite Comm. Start/Stop
Satellite Terminal UnTrasmit
State
Stop
Setting has been completed
ESC
Exec
ESC
Select Item
+
+
Exec
Start
Push ESC and return to Main
Menu Screen.
+
+
OK
Satellite Terminal: Initialize
Satellite Terminal No.
Confirmation
Communicating State
Check
Enter Satellite Comm.
Start/Stop
ESC
Information C/U: Various Setup
Screen
CAUTION: This procedure need not be done
in normal.
T5-3-18
TROUBLESHOOTING / e-Wheel
1.10 Control Data: Initialize
Push Control Data: Initialize.
Select Item
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: Initialize
ESC
Information C/U: Various Setup
Screen
Push Init and the controller
operating data is initialized.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
Push ESC and return to Main
Menu Screen.
Select Item
Control Data: Initialize
+ Information C/U: Initialize
Is control data initialized?
Init
i
Initialization has been
completed.
Initialization has been
completed.
ESC
Init
ESC
+ Enter Model and Serial
No.
+ Enter Date and Time
+ Control Data: Initialize
OK
ESC
Information C/U: Various Setup
Screen
Control Data: Initialize Screen
T5-3-19
TROUBLESHOOTING / e-Wheel
2. Self-Diagnosing
After starting Dr. ZX,
Self-Diagnostic Result.
Push Fault of ICF Controller. If
there is no trouble, No Problem is
displayed.
push
Self-diagnosing of controllers
below hasn completed.
Select Function
+
Self-Diagnostic Result
+
Select Controller
Self-Diagnosing
Engine Controller
No Problem
Main Controller
Fault
To the
lower
Monitor Controller No Problem
ICF Controller
ESC
ESC
ESC
Function Selection Screen
Change the page and
the fault code in back
and forth is displayed.
Push Details, and Details and
Corrective Action are displayed.
Push ESC and Retry B Screen is
Displayed.
Push ESC and Retry B Screen is
Displayed.
ICF Controller
Problem was detected.
14000
Fault
Controller Self-Diagnosing Screen
Push Retry B and return to Controller
Self-Diagnosing Screen after controller
self-diagnsing.
Push ESC and return to Controller
Self-Diagnosing Screen.
Fault Code 14000-2
14001
Details
Details
CAN Communication Error
ESC
Corrective Action
1)Retry B
2)Check Harness
3)
Retry B
Do you want to escape?
ESC
Details
ESC
ESC
Fault Code Screen
Retry B
Retry B Screen
Execute
Retry B
ESC
Self-diagnosing of controllers
below hasn completed.
Engine Controller
No Problem
Main Controller
Fault
Monitor Controller No Problem
ICF Controller
Fault
ESC
Controller Self-Diagnosing Screen
T5-3-20
ESC
TROUBLESHOOTING / e-Wheel
(Blank)
T5-3-21
TROUBLESHOOTING / e-Wheel
LIST OF ICF FAULT CODE
Fault Code
Details
14000-2
Abnormal CAN Communication
CAN Communication Error
14001-2
Abnormal Flash Memory
Read / Write Error
14002-2
Abnormal External RAM
Read / Write Error
14003-2
Abnormal EEPROM
Sum Check Error
Remedy
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, check the following
item.
• Check the CAN communication line (check the
h retry) B in self-diagnosing and execute the following
Execute
item.
• Execute 1.5 Information C/U: Initialize (T5-3-14).
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, check the following
item.
1. Execute 1.4 Enter Model and Serial No. (T5-3-13).
2. Execute 1.10 Control Data: Initialize (T5-3-19).
Then, execute self-diagnosing and execute retry B.
14006-2
Communication Error
Execute retry B in self-diagnosing.
Impossible to communicate with MC If this error code is displayed after re-try, check the following
item.
• Check the communication line.
• Check the power source line of satellite terminal.
• Check the fuse.
Then, execute self-diagnosing and execute retry B.
14008-2
Abnormal RAM
Road / Write Error
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, replace the
controller.
T5-3-22
TROUBLESHOOTING / e-Wheel
LIST OF FAULT CODE OF SATELLITE
COMMUNICATION TERMINAL
Fault Code
Details
14100-2
Inside Error
Abnormal EEPROM
14101-2
Inside Error
Abnormal IB/OB Queue
14102-2
Inside Error
Abnormal Local Loup Back
14103-2
Communication Error
The satellite is not found.
14104-2
Inside Error
Fail 1 of Remote Loup Back
14105-2
Communication Error
Fail 2 of Remote Loup Back
14106-2
Abnormal Harness
Sending and receiving data are
unmatched.
Remedy
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, replace the
controller.
T5-3-23
TROUBLESHOOTING / e-Wheel
SATELLITE COMMUNICATION SYSTEM
The satellite communication system is used for
maintenance of the machine, “e-Service” by
transmitting various data of the machine regularly via
a low earth orbit satellite.
Communication
Aerial
GPS
Aerial
NOTE: Depending on the circumstances of the
machine (ex. in the constructions, in the
tunnel, affected by the surrounding
building and affected of noise), the data
transfer rate may become slower, or the
communication might not be established.
The satellite communication system using
a low earth orbit satellite transmits digital
data through the radio wave. If there is
excessively noise or use of electrical
equipment which causes noise near the
machine, they cause reduces data transfer
rate or communication might not be
established at worst.
The satellite communication system consists of
satellite communication terminal, GPS aerial and
communication aerial.
The functions of each equipment are:
• Satellite Communication Terminal
T4GB-05-07-001
Satellite
Communication
Terminal
Receives the data from ICF and GPS aerial, and
sends the data to the communication aerial.
• GPS Aerial
Receives location information of the machine
from a low earth orbit satellite.
• Communication Aerial
Communicates the data with a low earth orbit
satellite.
T4GB-05-07-002
T5-3-24
TROUBLESHOOTING / e-Wheel
On the machine equipped with the satellite
communication system, the data are sent according to
the condition as follows:
Kinds of data sent from the machine by using satellite
communication:
Items
Kinds of Data
Periodical
Daily Report Data, Latest
Transmission
Information, Fuel Level
Condition
Location The data are sent once a day. In order to
avoid
congested
traffic
in
the
communication line, the data is sent
randomly between 0:00 and 02:00.
Transmitting Data at Latest Location Information
The data is sent only when the machine
Engine Start
is moved more than 5 km from the place
where it is recorded lastly.
Emergency
Alarm and Error Information
The transmission starts immediately
Transmission
when the alarm and error occurs.
Hour Meter 100 Hours Frequency Distribution Information
The data is sent when the hour meter
Transmission
exceeds every 100 hours.
T5-3-25
TROUBLESHOOTING / e-Wheel
(Blank)
T5-3-26
TROUBLESHOOTING / Component Layout
MAIN COMPONENT LAYOUT (OVERVIEW)
1
2
3
4
5
6
12
7
11
10
9
T4HA-01-02-008
8
1 - Bucket
2 - Bell Crank
4 - Head Light
5 - Front Working Light
3 - Bucket Cylinder
6 - Rear Working Light
(Optional)
7 - Rear Working Light
8 - Rear Combination Light
(Turn Signal, Hazard Light
Clearance Light, Brake
Light and Reverse Light)
9 - Turn Signal, Hazard Light
and Clearance Light
T5-4-1
10 - Lift Arm Cylinder
11 - Lift Arm
12 - Bucket Link
TROUBLESHOOTING / Component Layout
MAIN COMPONENT LAYOUT (UPPERSTRUCTURE)
1
2
3
4
5
22
21
20
19
18
17
15
16
6
15
7
8
9
14
13
12
11
10
T4HA-01-02-009
123456-
Charging Block
Pilot Valve
Brake Valve
Steering Pilot Valve
Steering Valve
Control Valve
7 - Stop Valve
8 - Pilot Shutoff Valve
9 - Pilot Filter
10 - Engine
11 - Fuel Filter
12 - Torque Converter Cooler
13 - Fuel Tank
14 - Oil Cooler
15 - Radiator
16 - Fan Motor
17 - Inter Cooler
18 - Reserve Tank
T5-4-2
19 - Engine Oil Filter
20 - Muffler
21 - Air Cleaner
22 - Hydraulic Tank
TROUBLESHOOTING / Component Layout
MAIN COMPONENT LAYOUT (TRAVEL SYSTEM)
1
2
3
4
5
6
9
8
7
T4HA-01-02-010
1 - Front Axle
2 - Propeller Shaft (Front)
3 - Steering Cylinder
45-
Pump Device
Transmission
5 - Rear Axle
6 - Propeller Shaft (Rear)
T5-4-3
7 - Steering Accumulator
8 - Brake Pressure Sensor
TROUBLESHOOTING / Component Layout
ELECTRIC COMPONENT LAYOUT (OVERVIEW)
Cab
(Refer to T5-4-5)
12
2
1
13
Engine and Fan Pump
(Refer to T5-4-10)
11
10
3
4
5
7
9
Pump Device
(Refer to T5-4-11)
Drive Unit
(Refer to T5-4-11)
6
8
T4HA-01-02-011
1 - Hydraulic Oil Level Switch
5-
Boost Pressure Sensor
2 - Air Filter Restriction Switch
6-
Fuel Level Sensor
3 - Reverse Buzzer
7-
Hydraulic Oil Temperature
Sensor
7 - Emergency Steering Pump
Delivery Pressure Switch
8 - Lift Arm Angle Sensor
(Optional)
9 - Bucket Proximity Switch
4 - Battery
T5-4-4
10 - Lift Arm Proximity Switch
11 - Implement Pressure Sensor
12 - Out Side Temperature
Sensor
TROUBLESHOOTING / Component Layout
ELECTRICAL SYSTEM (CAB)
1
2
3
Monitor and Switches
(Refer to T5-4-8)
4
Right Consol
(Refer to T5-4-7)
6
5
Controller and Relays
(Refer to T5-4-6)
T4GB-01-02-006
1 - Radio
2 - Auxiliary Switch Panel
(Optional)
3 - Speaker
4 - Rear Wiper Motor
5 - Brake Lamp Switch
T5-4-5
6 - Front Wiper Motor
TROUBLESHOOTING / Component Layout
Controller and Relays
6
7
T4GB-01-02-006
11
5
4
1
15
16
17
18
19
2
20
21
22
23
24
12
8
13
9
14
10
3
25
26
27
28
29
30
31
32
33
34
T4GC-01-02-021
1-
Flasher Relay
2-
9-
Front Window Heater Relay
Option Controller
(Optional)
3 - ECM1
10 - Neutral Relay
11 - Rear Window Heater Relay
4-
MCF
12 - Wiper Relay (Left)
5-
ICF
13 - Wiper Relay (Right)
6-
Dr.ZX Connector
14 - Reverse Light Relay (A-R5)
7-
Fuse Box
15 - Brake Light Relay (A-R4)
89-
Fog Light Relay (Optional)
Auxiliary
16 - High Beam Relay (A-R3)
17 - Head Light Relay (Right)
(A-R2)
T4GB-01-02-022
18 - Head Light Relay (Left)
(A-R1)
19 - Emergency Steering Relay
(A-R10)
20 - Hone Relay (A-R9)
21 - Turn Signal Relay (Right)
(A-R8)
22 - Working Light Relay (Rear)
(A-R7)
23 - Working Light Relay (Front)
(A-R8)
24 - Front Wiper Relay (B-R5)
25 - Neutral Relay (B-R4)
T5-4-6
26 - Load Dump Relay (B-R3)
27 - Parking Brake Relay
(B-R2)
28 - Parking Brake Relay
(B-R1)
29 - Fuel Pump Relay (B-R10)
30 - Main Relay (B-R9)
31 - Rear Washer Relay (B-R8)
32 - Turn Signal Relay (Left)
(B-R7)
33 - Rear Wiper Relay (B-R6)
TROUBLESHOOTING / Component Layout
Right Console
T4GB-01-02-006
2
3
4
6
5
7
1
8
9
10
18
17
16
15
14
13
12
T4GB-01-02-023
11
1 - Down Shift Switch
2 - Bucket Operation Lever
3 - Lift Arm Control Lever
4 - Forward/Reverse Switch
5 - Hone Switch
6 - Auxiliary Control Lever
(Optional)
7 - Quick Coupler Switch (Optional)
8 - Lift Arm Auto Leveler Downward
Set Switch (Optional)
9 - Lift Arm Auto Leveler Upward
Set Switch (Optional)
10 - Front Control Lock Lever
11 - Emergency Steering Check
Switch
12 - Fan Reverse Switch
13 - Fog Light Switch (Optional)
15 - Forward/Reverse Selector
Switch
16 - Cigar Lighter
17 - Up-shift/Down-shift Switch
14 - Ride Control Switch
(Optional)
18 - Hold Switch
T5-4-7
TROUBLESHOOTING / Component Layout
Monitor and Switches
1
2
T4GB-01-02-006
14
3
13
12
4
5
11
6
7
10
9
8
1 - Monitor Panel
(Refer to T5-4-9)
2 - Driving Mode Switch
3 - Turn Signal Lever/Head Light
Switch/Dimmer Switch
4 - Parking Brake Switch
T4GB-01-02-024
5 - Work Mode Selector Switch
9 - Front Wiper Switch
12 - Rear Wiper Switch
6 - Clutch Cat Position Switch
10 - Forward/Reverse Lever
and Shift Switch
11 - Air Conditioner Switch
Panel
13 - Working Light Switch
7 - Key Switch
8 - Steering Column Tilt
/Telescopic Lever
T5-4-8
14 - Hazard Light Switch
TROUBLESHOOTING / Component Layout
Monitor Panel
1
2
3
4
5
6
7
8
9
10
11
34
12
33
13
14
32
15
31
T4GB-01-02-001
30
29
28
1 - Coolant Temperature
Gauge
2 - Transmission Oil
Temperature Gauge
3 - Turn Signal Indicator
(Left)
4 - High Beam Indicator
5 - Working Light Indicator
6 - Turn Signal Indicator
(Right)
7 - Monitor Display
8 - Stop Indicator
9 - Service Indicator
27
26
25
24 23
22
10 - Parking Brake Indicator
21
20
19
18
11 - Clearance Light Indicator
19 - Lever Steering Indicator
(Optional)
20 - Monitor Mode Selector
12 - Fuel Gauge
21 - Glow Signal
13 - Brake Low Oil Pressure
Indicator
14 - Brake Low Oil Level
Indicator
15 - Emergency Steering
Indicator (Optional)
16 - Low Steering Oil Pressure
Indicator
17 - Seat Belt Indicator
22 - Monitor Display Selector (Up)
23 - Maintenance Indicator
24 - Monitor Display selector
(Down)
25 - Forward/Reverse Switch
Indicator
26 - Water Separator Indicator
18 - Discharge Warning
Indicator
T5-4-9
17
16
27 - Engine Warning Indicator
28 - Overheat Indicator
29 - Engine Low Oil Pressure
Indicator
30 - Air Filter Restriction Indicator
31 - Transmission Warning
Indicator
32 - Transmission Oil Filter
Restriction Indicator
33 - Hydraulic Oil Temperature
Indicator
34 - Transmission Oil
Temperature Indicator
TROUBLESHOOTING / Component Layout
ENGINE AND FAN PUMP
1
2
3
4
5
6
7
8
View A
13
15
12
A
14
11
10
9
T4HA-01-02-007
1 - Engine Oil Filter
5 - Fuel Filter
9 - ECM2
2 - Engine Oil Combination
Sensor (Temperature and
Pressure)
3 - Alternator
6 - Start and Stop Switch
10 - Fuel Cooler (ECM2 Cooler)
13 - Fan Pump (Not shown in
the image)
14 - Top Dead Center Sensor
7 - Inlet Air Combination
Sensor (Temperature and
Pressure)
8 - Coolant Temperature
Sensor
11 - Low Pressure Fuel Pump
15 - Crank Revolution Sensor
4 - Starter
12 - Fuel Temperature Sensor
T5-4-10
TROUBLESHOOTING / Component Layout
PUMP DEVICE
1
2
3
6
5
T4GB-01-02-009
4
DRIVE UNIT
7
21
8
9
13
14
15
16
17
18
20
12
19
11
10
T4GC-01-02-001
1 - Main Pump
7-
2 - Regulator
Torque Converter Input
Speed Sensor
8 - Air Breather
3 - Priority Valve
9-
4 - Pump Delivery Pressure
Switch
5 - Pilot Pump
10 - Vehicle Speed
Sensor
11 - Transmission Output
Speed Sensor
Charge Pump
12 - Transmission Middle Shaft
Sensor
13 - Forward Clutch Solenoid
Valve
14 - Reverse Clutch Solenoid
Valve
15 - 1st Clutch Solenoid Valve
16 - 2nd Clutch Solenoid Valve
6 - Steering Relief Valve
T5-4-11
17 - 3rd Clutch Solenoid Valve
18 - 4th Clutch Solenoid Valve
19 - Transmission Control Valve
20 - Parking Brake Pressure
Switch
21 - Regulator Valve
TROUBLESHOOTING / Component Layout
CONTROL VALVE
5
1
4
3
2
T4GB-03-02-002
1 - Over Load Relief Valve
(Lift Arm: Bottom)
2 - Over Load Relief Valve
(Bucket: Bottom)
3 - Over Load Relief Valve
(Bucket: Rod)
4 - Make-up Valve
(Lift Arm: Rod)
T5-4-12
5 - Main Relief Valve
TROUBLESHOOTING / Component Layout
RIDE CONTROL VALVE (OPTIONAL)
1
2
CHARGING BLOCK
3
4
5
6
10
T4GB-01-02-014
9
8
7
T4GB-01-02-013
FAN MOTOR
10
11
12
T4GB-01-02-012
1 - Overload Relief Valve
2 - Ride Control Solenoid
Valve
3 - Ride Control Accumulator
5 - Service Brake Accumulator
(Front)
6 - Service Brake Accumulator
(Rear)
7 - Relief Valve
89-
Pilot Relief Valve
Pump Torque Control
Solenoid Valve
10 - Parking Brake Solenoid
Valve
4 - Pilot Accumulator
T5-4-13
11 - Reverse Control Solenoid
Valve
12 - Relief Valve
13 - Flow Control Solenoid
Valve
TROUBLESHOOTING / Component Layout
STEERING VALVE
1
2
T4GB-01-02-020
EMERGENCY STEERING PUMP
3
4
5
6
T4GB-01-02-010
1 - Overload Relief Valve
2 - Overload Relief Valve
3 - Electric Motor
4 - Gear Pump
5 - Check Valve
T5-4-14
6-
Relief Valve
TROUBLESHOOTING / Component Layout
(Blank)
T5-4-15
TROUBLESHOOTING / Component Layout
COMPONENTS IN CONTROL VALVE
1
2
3
4
5
6
8
7
8
9
11
10
T4GB-03-02-008
T5-4-16
TROUBLESHOOTING / Component Layout
D
10
C
7
8
6
8
A
E
5
4
3
T4GB-03-02-009
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4 - Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7 - Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9 - Low-pressure Relief Valve
T5-4-17
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
TROUBLESHOOTING / Component Layout
1
2
3
4
5
6
8
7
8
9
11
10
T4GB-03-02-008
T5-4-18
TROUBLESHOOTING / Component Layout
Section A*
11
7
6
8
8
Section B*
1
2
5
4
T4GB-03-02-010
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4-
Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7-
Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9-
*: Refer to T5-4-17
T5-4-19
Low-pressure Relief Valve
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
TROUBLESHOOTING / Component Layout
1
2
3
4
5
6
8
7
8
9
10
11
T4GB-03-02-008
T5-4-20
TROUBLESHOOTING / Component Layout
Section C*
10
9
Section D*
C
3
E
Section E*
3
T4GB-03-02-011
1 - Flow Control Valve
(Poppet)
2 - Flow Control Valve
(Changeover Valve)
3 - Negative Control Valve
4-
Overload Relief Valve
(Bucket: Bottom End)
5 - Overload Relief Valve
(Bucket: Rod End)
6 - Overload Relief Valve
(Lift Arm: Bottom End)
7-
Make-up Valve
(Lift Arm: for Rod)
8 - Restriction Valve
9-
*: Refer to T5-4-17.
T5-4-21
Low-pressure Relief Valve
10 - Main Relief Valve
11 - Load Check Valve
(Lift Arm Circuit)
TROUBLESHOOTING / Component Layout
COMPONENTS IN STEERING VALVE
4
1
2
3
Port T
Port A
Port B
Port Pa
Port Pb
5
Port A: Pressure for Steering
Right
Port P: From Main Pump
6
Port DR
Port P
Port LS
Port B: Pressure for Steering
Left
Port T: Return to Hydraulic Oil
Tank
4
5
Port Pa: Pilot Pressure for
Steering Right
Port LS: To Port LS of Priority
Valve
T5-4-22
T4GB-03-04-002
Port Pb: Pilot Pressure for
Steering Left
Port DR: Return to Hydraulic Oil
Tank
TROUBLESHOOTING / Component Layout
A
2
3
C
B
T4GB-03-04-001
1 - Spool
2 - Overload Relief Valve
3 - Overload Relief Valve
4 - Lord Check Valve
5 - Variable Orifice
6 - Fixed Orifice
T5-4-23
TROUBLESHOOTING / Component Layout
4
1
2
3
Port T
Port A
Port B
Port Pa
Port Pb
5
Port A: Pressure for Steering
Right
Port P: From Main Pump
6
Port DR
Port P
Port LS
Port B: Pressure for Steering
Left
Port T: Return to Hydraulic Oil
Tank
4
5
Port Pa: Pilot Pressure for
Steering Right
Port LS: To Port LS of Priority
Valve
T5-4-24
T4GB-03-04-002
Port Pb: Pilot Pressure for
Steering Left
Port DR: Return to Hydraulic Oil
Tank
TROUBLESHOOTING / Component Layout
Section A
*
7
Port P
Port DR
1
Port T
Section B
*
3
Port LS
Port B
Port A
2
Port Pb
Port Pa
4
5
7
Section C
*
T4GB-03-04-003
4
6
T4GB-03-04-006
1 - Spool
2 - Overload Relief Valve
34-
Overload Relief Valve
Lord Check Valve
5 - Variable Orifice
6 - Fixed Orifice
*: Refer to T5-4-23.
T5-4-25
7 - Passage A
TROUBLESHOOTING / Component Layout
COMPONENTS IN CHARGING BLOCK
1
2
3
4
5
6
7
8
22
9
10
11
21
12
13
14
20
15
16
17
18
T4GB-03-06-013
4
19
1 - Service Brake Accumulator
(Rear)
2 - Adaptor
9-
Priority Valve
3 - Port M2
(To Rear End of Brake Valve)
4 - Check Valve
5 - Port M1
(To Front End of Brake Valve)
6 - Service Brake Accumulator
(Front)
7 - Service Brake Pressure Sensor
8 - Port P (from Pilot Pump)
11 - Port DR (To Hydraulic Oil Tank)
10 - Pilot Relief Valve
12 - Port DR2 (To Hydraulic Oil Tank)
13 - Port PS1
(To Steering Pilot Valve)
14 - Port X
（To Main Pump Regulator）
15 - Parking Brake Pressure Sensor
T5-4-26
16 - Port BR3 （To Parking Brake）
17 - Port PS2
(To Main Pump Regulator
and Ride Control Valve (Optional))
18 - Pilot Accumulator
19 - Port PP （To Pilot Shutoff Valve）
20 - Parking Brake Solenoid Valve
21 - Pump Torque Control Proportional
Solenoid Valve
22 - Relief Valve
TROUBLESHOOTING / Component Layout
2
Port for Attaching
Service Brake
Accumulator (Rear)
Port for Attaching
Service Brake
Accumulator (Front)
3
5
Pump Torque
Control
Proportional
Solenoid Valve
13
Parking Brake
Solenoid Valve
17
Port for Attaching
Pilot Accumulator
T4GB-03-06-001
T5-4-27
TROUBLESHOOTING / Component Layout
1
2
3
4
5
6
7
8
22
9
10
11
21
12
13
14
20
15
16
17
18
T4GB-03-06-013
4
19
1 - Service Brake Accumulator
(Rear)
2 - Adaptor
9-
Priority Valve
3 - Port M2
(To Rear End of Brake Valve)
4 - Check Valve
5 - Port M1
(To Front End of Brake Valve)
6 - Service Brake Accumulator
(Front)
7 - Service Brake Pressure Sensor
8 - Port P (from Pilot Pump)
11 - Port DR (To Hydraulic Oil Tank)
10 - Pilot Relief Valve
12 - Port DR2 (To Hydraulic Oil Tank)
13 - Port PS1
(To Steering Pilot Valve)
14 - Port X
（To Main Pump Regulator）
15 - Parking Brake Pressure Sensor
T5-4-28
16 - Port BR3 （To Parking Brake）
17 - Port PS2
(To Main Pump Regulator
and Ride Control Valve (Optional))
18 - Pilot Accumulator
19 - Port PP （To Pilot Shutoff Valve）
20 - Parking Brake Solenoid Valve
21 - Pump Torque Control Proportional
Solenoid Valve
22 - Relief Valve
TROUBLESHOOTING / Component Layout
11
Section V-V*
10
14
Section U-U*
12
21
15
16
Section T-T*
20
Section S-S
19
*
18
4
T4GB-03-06-003
*Refer to T5-4-27.
4
T5-4-29
TROUBLESHOOTING / Component Layout
1
2
3
4
5
6
7
8
22
9
10
11
21
12
13
14
20
15
16
17
18
T4GB-03-06-013
4
19
1 - Service Brake Accumulator
(Rear)
2 - Adaptor
9-
Priority Valve
3 - Port M2
(To Rear End of Brake Valve)
4 - Check Valve
5 - Port M1
(To Front End of Brake Valve)
6 - Service Brake Accumulator
(Front)
7 - Service Brake Pressure Sensor
8 - Port P (From Pilot Pump)
11 - Port DR (To Hydraulic Oil Tank)
10 - Pilot Relief Valve
12 - Port DR2 (To Hydraulic Oil Tank)
13 - Port PS1
(To Steering Pilot Valve)
14 - Port X
（To Main Pump Regulator）
15 - Parking Brake Pressure Sensor
T5-4-30
16 - Port BR3 （To Parking Brake）
17 - Port PS2
(To Main Pump Regulator
and Ride Control Valve (Optional))
18 - Pilot Accumulator
19 - Port PP （To Pilot Shutoff Valve）
20 - Parking Brake Solenoid Valve
21 - Pump Torque Control Proportional
Solenoid Valve
22 - Relief Valve
TROUBLESHOOTING / Component Layout
Section Z-Z*
6
1
4
Section Y-Y*
7
8
*
Section X-X
4
Section W-W
*
22
9
*Refer to T5-4-27
T5-4-31
T4GB-03-06-004
TROUBLESHOOTING / Component Layout
COMPONENTS IN RIDE CONTROL VALVE
Lift Arm
Cylinder
Ride Control
Accumulator
5
Ride Control Valve
SP
3
Pi
1
4
B
A
2
To Hydraulic Oil Tank
T
From Charging
Block
T4GB-03-08-002
1 - Ride Control Solenoid Valve
2 - Charge-cut Spool
3 - Overload Relief Valve
4 - Spool
5 - Drain Plug
T5-4-32
TROUBLESHOOTING / Component Layout
A
3
5
1
T4GB-03-08-001
T5-4-33
TROUBLESHOOTING / Component Layout
Lift Arm
Cylinder
Ride Control
Accumulator
5
Ride Control Valve
SP
3
Pi
1
4
B
A
2
To Hydraulic Oil Tank
T
From Charging
Block
T4GB-03-08-002
1 - Ride Control Solenoid Valve
2 - Charge-cut Spool
34-
Overload Relief Valve
Spool
5-
T5-4-34
Drain Plug
TROUBLESHOOTING / Component Layout
Section A*
Port Pi
To Ride Control
Accumulator
1
Port SP
3
Port B
Port A
Port T
2
*Refer to T5-4-33
T5-4-35
4
T4GB-03-08-003
TROUBLESHOOTING / Component Layout
FRONT VIEW OF TRANSMISSION
1
A
2
5
B
6
B
C
3
C
7
8
4
A
T4GC-03-09-003
1 - Breather
2 - From Oil Cooler
3 - Control Valve
4 - Oil Feed Port
5 - Charging Pump
6 - Rotation Sensor (A)
T5-4-36
7 - Rotation Sensor (B)
8 - Vehicle Speed Sensor
TROUBLESHOOTING / Component Layout
SIDE VIEW OF TRANSMISSION
2
1
3
4
3
5
6
9
10
7
8
T4GC-03-09-005
1 - Converter Inlet Pressure
Port
2 - Regulator Valve
3 - Forward Clutch Pressure
Port
4 - Reverse Clutch Pressure
Port
5 - 1st Speed Clutch Pressure
Port
6 - 2nd Speed Clutch Pressure
Port
7 - 3rd Speed Clutch Pressure
Port
8 - 4th Speed Clutch Pressure
Port
9 - Parking Brake Release
Pressure Inlet
T5-4-37
10 - Parking Brake Pressure
Switch Port
TROUBLESHOOTING / Component Layout
REAR VIEW OF TRANSMISSION
1
D
D
2
3
9
8
7
E
6
4
Detail E
5
T4GC-03-09-004
Section DD
1 - Engine Speed Sensor
2 - Suction Tube
3 - Hose
4 - Strainer
5 - To Oil Cooler
6 - Converter Outlet Boss
7 - Oil Pressure Gauge Port
8 - Safety Valve
9 - Spring
T5-4-38
TROUBLESHOOTING / Component Layout
CROSS-SECTIONAL DRAWING OF TORQUE CONVERTER
7
8
9
10
11
1
2
3
4
5
6
T4GC-03-09-001
1 - Cover Wheel
2 - Input Plate
3 - Turbine
4 - Stator
5 - Input Guide
6 - Stator Hub
7 - Impeller
8 - Impeller Hub
9 - Pump Drive Gear
T5-4-39
10 - Guide Carrier
11 - Turbine Shaft
TROUBLESHOOTING / Component Layout
CROSS-SECTIONAL DRAWING OF TRANSMISSION
1
2
14
3
4
Section BB*
13
5
12
11
10
9
8
*
Section CC
15
1234-
Charging Pump
Pump Drive Shaft
Forward Clutch
Distributor Cap
5678-
7
Section AA*
T4GC-03-09-006
16
Parking Brake
Front Output Flange
Output Shaft
Drain Plug
6
9 - Rear Output Flange
10 - 1st & 2nd Speeds Clutch
11 - Distributor Cap
12 - Idler Shaft
*Refer to T5-4-36
T5-4-40
13 - Torque Converter
14 - Reverse Clutch
15 - Distributor Cap
16 - 3rd & 4th Speeds Clutch
TROUBLESHOOTING / Component Layout
CROSS-SECTIONAL DRAWING OF CLUTCH SHAFT
1
2
3
4
5
A
6
7
8
9
10
11
B
12
13
Detail B
Detail A
1234-
Hub Gear
End Plate
Return Spring
Seal Ring (Inner)
567-
Bleed Valve
Seal Ring (Outer)
Piston
T4GC-03-09-007
8 - Disk
9 - Plate
10 - Hub Gear
T5-4-41
11 - Shaft
12 - Plug
13 - Seal Ring
TROUBLESHOOTING / Component Layout
CROSS-SECTIONAL DRAWING OF TRANSMISSION REGULATOR VALVE
Normally
Small Hole of
Regulator Spool
Regulator Spool
Spring
From
Charging Pump
T4GC-03-09-025
When overflowing
Regulator Spool
Spring
To Transmission
Control Valve
From
Charging Pump
To Torque
Converter
T5-4-42
T4GC-03-09-026
TROUBLESHOOTING / Component Layout
CROSS-SECTIONAL DRAWING OF TRANSMISSION CONTROL VALVE
1
2
3
24
4
5
23
6
7
8
22
9
21
10
11
12
20
13
14
19
15
16
17
18
T4GC-03-09-029
From
Charging Pump
1 - Solenoid Body
7 - Emergency Reverse Spool
2 - Valve Body
8 - Reverse Modulation Spool
3 - Cover
9 - Reverse Modulation Spring
4 - Emergency Forward Spool
10 - 1st Speed Modulation
Spool
11 - 1st Speed Modulation
Spring
12 - Emergency 2nd Speed
Spool
5 - Forward Modulation Spool
6 - Forward Modulation Spring
13 - 2nd Speed Modulation
Spool
14 - 2nd Speed Modulation
Spring
15 - 3rd Speed Modulation
Spool
16 - 3rd Speed Modulation
Spring
17 - 4th Speed Modulation
Spool
18 - 4th Speed Modulation
Spring
T5-4-43
19 - 4th Speed Proportional
Solenoid Valve
20 - 3rd Speed Proportional
Solenoid Valve
21 - 2nd Speed Proportional
Solenoid Valve
22 - 1st Speed Proportional
Solenoid Valve
23 - Reverse Proportional
Solenoid Valve
24 - Forward Proportional
Solenoid Valve
TROUBLESHOOTING / Component Layout
(Blank)
T5-4-44
TROUBLESHOOTING / Troubleshooting A
TROUBLESHOOTING A PROCEDURE
Refer to troubleshooting A procedure in case any fault
codes are displayed after diagnosing by using Dr. ZX
or the service mode of monitor unit.
• How to Read Troubleshooting Flow Charts
YES(OK)
・
(2)
After completing the checking and/or measuring procedures in box (1),
select YES (OK) or NO (NOT OK) and proceed to box (2) or (3).
(1)
NO(NOT OK)
・
· Key switch: ON
(3)
Instructions, reference, and/or inspection methods and/or measurements are occasionally
described under the box. If incorrectly checked or measured, not only will troubleshooting
be unsuccessful but also damage to the components may result.
・
Use Dr. ZX for descriptions in the double-line box.
・
Causes of machine problems are stated in the thick-line box. Scanning quickly through the
thick-line boxes allows you to estimate the possible causes before actually following the
flow chart.
NOTE: Harness end connector viewed from the
open end side by the all connectors image
shown in this section.
Harness
Open End
Side
Harness End Connector
T158-05-03-001
T5-5-1
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE LIST
Controller Hardware Failure
Fault
Trouble
Code
11000-2 Abnormal EEPROM
Faulty MC
All Control
11001-2
Abnormal RAM
Faulty MC
All Control
11002-2
Abnormal A/D (Analog to Digi- Faulty MC
tal) Converter
Abnormal Sensor Voltage
Faulty sensor because
shorted circuit in harness
Faulty MC
CAN Communication Error
Faulty sensor because
shorted circuit in harness
Faulty MC
11003-3
11004-2
Cause
T5-5-2
Influenced Control
All Control
of All Control
of All Pump Control
All Transmission Control
All Engine Control
Hydraulic Drive Fan Cooling
Control
Ride Control
CAN Cycle Data Communication
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
There is something wrong with machine operation.
Remark
Retrial B
Replace MC
There is something wrong with machine operation.
Retrial B
Replace MC
As the latest, normal value AD (analog to digital) is enabled, the Retrial B
machine may be operated incorrectly or slowly.
Replace MC
Inputs from all sensors are uncertain.
Retrial B
Check Harness
Replace MC
-1
As engine speed is kept at 1000 min (1000 rpm), the work may Retrial B
be inoperable.
Check CAN Harness
Replace MC
T5-5-3
TROUBLESHOOTING / Troubleshooting A
Engine Failure
Fault
Trouble
Code
11103-3 Abnormal Accelerator
High Voltage
11103-4
Abnormal Accelerator
Low Voltage
11105-3
Abnormal Torque
Input Shaft Sensor
Cause
Influenced Control
Pedal Voltage: 4.75 V or higher
Pump Torque Decrease Control
Engine Accelerator Pedal
Control
Pedal Voltage: Less than 0.25 V
Pump Torque Decrease Control
Engine Accelerator Pedal
Control
Hydraulic Drive Fan Cooling
Control
Converter Engine speed=0 min-1
ECM 1 engine speed>500 min-1
T5-5-4
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
The accelerator pedal is inoperable.
Retrial B
Engine speed kept at 1000 min-1 (1000 rpm), the work may be Check Harness
inoperable.
Replace Accelerator Pedal
Replace MC
The accelerator pedal is inoperable.
Retrial B
Engine speed kept at 1000 min-1 (1000 rpm), the work may be Check Harness
inoperable.
Replace Accelerator Pedal
Replace MC
As fan speed is controlled by temperature only, when oil and Retrial B
coolant temperature are high, the machine starts slowly.
Check Harness
Fuel consumption becomes bad.
Replace Torque Converter Input Shaft
Sensor
Replace MC
T5-5-5
TROUBLESHOOTING / Troubleshooting A
Pump Failure
Fault
Trouble
Cause
Influenced Control
Code
11204-3 Abnormal Pump Delivery Output voltage: 4.75 V or Disable Pump Torque Decrease
Pressure Sensor High Volt- higher
Control
age
11204-4
Abnormal Pump Delivery Output voltage: Less than Disable Pump Torque Decrease
Pressure Sensor Low Voltage 0.25 V
Control
11209-3
Abnormal Implement Pres- Output voltage: 4.75 V or Disable Pump Torque Decrease
sure Sensor High Voltage
higher
Control
11209-4
Abnormal Implement Pres- Output voltage: Less than Disable Pump Torque Decrease
sure Sensor Low Voltage
0.25 V
Control
T5-5-6
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As the pump is controlled by pump standard torque control, work ef- Retrial B
ficiency of the front attachment becomes low.
Check Harness
Fuel consumption becomes bad.
Replace Pump Delivery Pressure Sensor
Replace MC
As the pump is controlled by pump standard torque control, work ef- Retrial B
ficiency of the front attachment becomes low.
Check Harness
Fuel consumption becomes bad.
Replace Pump Delivery Pressure Sensor
Replace MC
As the pump is controlled by pump standard torque control, work ef- Retrial B
ficiency of the front attachment becomes low.
Check Harness
Fuel consumption becomes bad.
Replace Implement Pressure Sensor
Replace MC
As the pump is controlled by pump standard torque control, work ef- Retrial B
ficiency of the front attachment becomes low.
Check Harness
Fuel consumption becomes bad.
Replace Implement Pressure Sensor
Replace MC
T5-5-7
TROUBLESHOOTING / Troubleshooting A
Pilot Failure
Fault
Trouble
Cause
Code
11312-3 Abnormal Brake Pedal Pres- Voltage: 4.75 V or higher
sure Sensor High Voltage
Influenced Control
Clutch Cut-Off Control
11312-4
Abnormal Brake Pedal Pres- Voltage: Less than 0.25 V
sure Sensor Low Voltage
Clutch Cut-Off Control
11313-3
Abnormal Parking Brake Pres- Output voltage: 4.75 V or higher
sure Sensor High Voltage
Parking Brake Indicator Control
11313-4
Abnormal Parking Brake Pres- Output voltage: Less than 0.25 Parking Brake Indicator Consure Sensor Low Voltage
V
trol
T5-5-8
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As clutch cut-off control is disabled, the clutch cut-off is inoper- Retrial B
able.
Check Harness
Fuel consumption becomes bad.
Replace Brake Pedal Pressure Sensor
Replace MC
As clutch cut-off control is disabled, the clutch cut-off is inoper- Retrial B
able.
Check Harness
Fuel consumption becomes bad.
Replace Brake Pedal Pressure Sensor
Replace MC
As the parking brake is forcibly released, the machine can travel Retrial B
with the parking brake switch ON.
Check Harness
Replace Parking Brake Pressure Sensor
Replace MC
As the parking brake is forcibly released, the machine can travel Retrial B
with the parking brake switch ON.
Check Harness
Replace Parking Brake Pressure Sensor
Replace MC
T5-5-9
TROUBLESHOOTING / Troubleshooting A
Proportional Solenoid Valve Failure
Fault
Trouble
Code
11412-2 Abnormal Feedback of Hydraulic
Drive Fan Flow Rate Control Solenoid Valve
Cause
Influenced Control
The feedback current Hydraulic
to MC becomes the Control
uncertain value
Drive
Fan
Cooling
11412-3
Abnormal Feedback High Current of The feedback current Hydraulic
Hydraulic Drive Fan Flow Rate Con- to MC exceeds the Control
trol Solenoid Valve
upper limit
Drive
Fan
Cooling
11412-4
Abnormal Feedback Low Current of While the command Hydraulic
Hydraulic Drive Fan Flow Rate Con- from MC is output, the Control
trol Solenoid Valve
feedback current to MC
is 56 mA or less
Drive
Fan
Cooling
11413-2
Abnormal Feedback of Pump Torque The feedback current Pump Standard Torque Control
Control Solenoid Valve
to MC becomes the
uncertain value
11413-3
Abnormal Feedback High Current of The feedback current Pump Standard Torque Control
Pump Torque Control Solenoid Valve to MC exceeds the
upper limit
11413-4
Abnormal Feedback Low Current of While the command Pump Standard Torque Control
Pump Torque Control Solenoid Valve from MC is output, the
feedback current to MC
is 56 mA or less
11414-2
Abnormal Feedback of Transmission
Clutch First Gear Proportional Solenoid Valve
11414-3
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch First Gear to MC exceeds the
Proportional Solenoid Valve
upper limit
The feedback current All Transmission Control
to MC becomes the
uncertain value
T5-5-10
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As the fan rotation is kept at maximum, the machine starts slowly.
Fuel consumption becomes bad.
Retrial B
Check Harness (Feedback line from the
flow rate control solenoid valve to MC)
Replace Hydraulic Drive Fan Flow Rate
Control Solenoid Valve
Replace MC
Retrial B
Check Harness (Feedback line from the
flow rate control solenoid valve to MC)
Replace Hydraulic Drive Fan Flow Rate
Control Solenoid Valve
Replace MC
Retrial B
Check Harness (Feedback line from the
flow rate control solenoid valve to MC)
Replace Hydraulic Drive Fan Flow Rate
Control Solenoid Valve
Replace MC
Retrial B
Check Harness (Feedback line from the
torque control solenoid valve to MC)
Replace Pump Torque Control Solenoid
Valve
Replace MC
Retrial B
Check Harness (Feedback line from the
torque control solenoid valve to MC)
Replace Pump Torque Control Solenoid
Valve
Replace MC
Retrial B
Check Harness (Feedback line from the
torque control solenoid valve to MC)
Replace Pump Torque Control Solenoid
Valve
Replace MC
Retrial B
Check Harness (Feedback line from first
gear proportional solenoid valve output to
MC)
Replace First Gear Proportional Solenoid
Valve
Replace MC
Retrial B
Check Harness (Feedback line from first
gear proportional solenoid valve output to
MC)
Replace First Gear Proportional Solenoid
Valve
Replace MC
As the fan rotation is kept at maximum, the machine starts slowly.
Fuel consumption becomes bad.
As the fan rotation is kept at maximum, the machine starts slowly.
Fuel consumption becomes bad.
As the pump is kept at minimum displacement, work efficiency of
the front attachment becomes low.
As the pump is kept at minimum displacement, work efficiency of
the front attachment becomes low.
As the pump is kept at minimum displacement, work efficiency of
the front attachment becomes low.
As speed is kept at second gear in spite of the shift switch, there
is some influence on the work.
As speed is kept at second gear in spite of the shift switch, there
is some influence on the work.
T5-5-11
TROUBLESHOOTING / Troubleshooting A
Fault
Code
11414-4
Trouble
Cause
Influenced Control
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch First Gear to MC is 20 mA or less
Proportional Solenoid Valve
11415-2
Abnormal Feedback of Transmission
Clutch Second Gear Proportional
Solenoid Valve
The feedback current All Transmission Control
to MC becomes the
uncertain value
11415-3
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch Second Gear to MC exceeds the
Proportional Solenoid Valve
upper limit
11415-4
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch Second Gear to MC is 20 mA or less
Proportional Solenoid Valve
11416-2
Abnormal Feedback of Transmission
Clutch Third Gear Proportional Solenoid Valve
11416-3
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch Third Gear to MC exceeds the
Proportional Solenoid Valve
upper limit
11416-4
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch Third Gear to MC is 20 mA or less
Proportional Solenoid Valve
11417-2
Abnormal Feedback of Transmission
Clutch Fourth Gear Proportional Solenoid Valve
The feedback current All Transmission Control
to MC becomes the
uncertain value
The feedback current All Transmission Control
to MC becomes the
uncertain value
T5-5-12
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from first gear
proportional solenoid valve output to MC)
Replace First Gear Proportional Solenoid Valve
Replace MC
As speed is kept at first gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from second gear
proportional solenoid valve output to MC)
Replace Second Gear Proportional Solenoid
Valve
Replace MC
As speed is kept at first gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from second gear
proportional solenoid valve output to MC)
Replace Second Gear Proportional Solenoid
Valve
Replace MC
As speed is kept at first gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from second gear
proportional solenoid valve output to MC)
Replace Second Gear Proportional Solenoid
Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from third gear
proportional solenoid valve output to MC)
Replace Third Gear Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from third gear
proportional solenoid valve output to MC)
Replace Third Gear Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from third gear
proportional solenoid valve output to MC)
Replace Third Gear Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from fourth gear
proportional solenoid valve output to MC)
Replace Fourth Gear Proportional Solenoid
Valve
Replace MC
T5-5-13
TROUBLESHOOTING / Troubleshooting A
Fault
Code
11417-3
Trouble
Cause
Influenced Control
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch Fourth Gear to MC exceeds the
Proportional Solenoid Valve
upper limit
11417-4
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch Fourth Gear to MC is 20 mA or less
Proportional Solenoid Valve
11418-2
Abnormal Feedback of Transmission
Clutch Forward Proportional Solenoid Valve
11418-3
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch Forward Pro- to MC exceeds the
portional Solenoid Valve
upper limit
11418-4
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch Forward Pro- to MC is 20 mA or less
portional Solenoid Valve
11419-2
Abnormal Feedback of Transmission
Clutch Reverse Proportional Solenoid Valve
11419-3
Abnormal Feedback High Current of The feedback current All Transmission Control
Transmission Clutch Reverse Pro- to MC exceeds the
portional Solenoid Valve
upper limit
11419-4
Abnormal Feedback Low Current of The feedback current All Transmission Control
Transmission Clutch Reverse Pro- to MC is 20 mA or less
portional Solenoid Valve
The feedback current All Transmission Control
to MC becomes the
uncertain value
The feedback current All Transmission Control
to MC becomes the
uncertain value
T5-5-14
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from fourth gear
proportional solenoid valve output to MC)
Replace Fourth Gear Proportional Solenoid
Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from fourth gear
proportional solenoid valve output to MC)
Replace Fourth Gear Proportional Solenoid
Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from forward
proportional solenoid valve output to MC)
Replace Forward Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from forward
proportional solenoid valve output to MC)
Replace Forward Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from forward
proportional solenoid valve output to MC)
Replace Forward Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from reverse
proportional solenoid valve output to MC)
Replace Reverse Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from reverse
proportional solenoid valve output to MC)
Replace Reverse Proportional Solenoid Valve
Replace MC
As speed is kept at second gear in spite of the shift switch, Retrial B
there is some influence on the work.
Check Harness (Feedback line from reverse
proportional solenoid valve output to MC)
Replace Reverse Proportional Solenoid Valve
Replace MC
T5-5-15
TROUBLESHOOTING / Troubleshooting A
Transmission Failure
Fault
Trouble
Code
11600-3 Abnormal Travel Speed Sensor
Cause
Influenced Control
The abnormal value below All Transmission Control
is detected with the clutch
connected.
• Travel speed sensor=0
min-1
• Middle shaft sensor>300
min-1
• Torque converter output
speed sensor>500 min-1
• Detected voltage under
the open circuit with key
ON: 4.5 V or higher
11600-4
Abnormal Low Voltage of Travel Detected voltage under the All Transmission Control
Speed Sensor
shorted circuit with key ON:
Less than 1.5 V
11601-3
Abnormal Torque Converter The abnormal value below Pump Torque Decrease Control
Output Speed Sensor
is detected with the clutch
connected.
• Torque converter output
speed sensor=0 min-1
• Middle shaft sensor>300
min-1
• Travel speed sensor>300
min-1
Abnormal Transmission Middle The abnormal value below All Transmission Control
Shaft Sensor
is detected with the clutch
connected.
• Middle shaft sensor =0
min-1
• Travel speed sensor>500
min-1
• Torque converter output
speed sensor>500 min-1
Abnormal
Forward/Reverse The forward/reverse sig- All Transmission Control
Lever
nals are turned ON for 80
ms or longer at the same
time.
11602-3
11904-2
11905-2
Abnormal
Switch
Forward/Reverse The forward/reverse sig- All Transmission Control
nals are turned ON for 80
ms or longer at the same
time.
T5-5-16
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
As travel speed is calculated at the middle shaft sensor, Retrial B
there is no influence on the machine. Travel speed moves Check Harness
over about 2 km/h when shifting the gears.
Replace Travel Speed Sensor
Replace MC
As travel speed is calculated at the middle shaft sensor, Retrial B
there is no influence on the machine. Travel speed moves Check Harness
over about 2 km/h when shifting the gears.
Replace Travel Speed Sensor
Replace MC
As travel speed rate becomes 0, torque decrease control is
disabled and base torque control is operable. Work efficiency and fuel consumption may become bad. There may
be some shock when shifting the gears.
Retrial B
Check Harness
Replace Torque Converter Output Speed Sensor
Replace MC
As backup travel speed calculation is disabled, travel Retrial B
speed is not displayed in case of the abnormal travel speed Check Harness
sensor.
Replace Transmission Middle Shaft Sensor
Replace MC
As the forward/reverse lever is forcibly turned to neutral in Retrial B
case of the abnormal forward/reverse lever, the machine Check Harness
cannot start.
Replace Forward/Reverse Lever
Replace MC
The forward/reverse lever only is operable in case of the Retrial B
abnormal forward/reverse switch.
Check Harness
Replace Forward/Reverse Switch
Replace MC
T5-5-17
TROUBLESHOOTING / Troubleshooting A
CAN Data Reception Failure
Fault
Trouble
Cause
Code
11910-2 Actual Engine Speed Receive Faulty Harness
Error
Faulty ECM
Received from ECM 1
11914-2
Radiator Coolant Temperature Faulty Harness
Receive Error
Faulty Monitor Unit
Received from Monitor Unit
11920-2
Fuel Flow Rate Receive Error
Received from ECM 1
Faulty Harness
Faulty ECM
T5-5-18
Influenced Control
Transmission Control
(Error judgment of
pulse sensor)
engine
Hydraulic Drive Fan Cooling
Control
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
Error of the torque converter input speed sensor cannot be Retrial B
judged.
Check CAN Communication Line
Replace Engine Speed Sensor
Replace MC
As the fan rotation is always kept at maximum, the machine Retrial B
starts slowly.
Check CAN Communication Line
Fuel consumption becomes bad.
Replace Monitor Unit
Replace MC
The fuel consumption is not displayed on the monitor.
T5-5-19
Retrial B
Check CAN Communication Line
Replace ECM 1 or 2
Replace MC
TROUBLESHOOTING / Troubleshooting A
Other Failures
Fault
Trouble
Cause
Code
11901-3 Hydraulic
Oil
Temperature Voltage: 4.52 V or higher
Sensor High Voltage
11901-4
Hydraulic
Oil
Temperature Voltage: Less than 0.23 V
Sensor Low Voltage
T5-5-20
Influenced Control
Auto-Warming Up Control
Hydraulic Drive Fan Cooling
Control
Auto-Warming Up Control
Hydraulic Drive Fan Cooling
Control
TROUBLESHOOTING / Troubleshooting A
Symptoms in Machine Operation When Trouble Occurs
Remedy
When temperature is low (hydraulic oil temperature is 0 °C
(32 °F) or less), the auto-warming up control is inoperable.
Fuel consumption becomes bad.
The hydraulic oil temperature calculating part is kept at
maximum.
Retrial B
Check Harness
Replace Hydraulic Oil Temperature Sensor
Replace MC
When temperature is low (hydraulic oil temperature is 0 °C
(32 °F) or less), the auto-warming up control is inoperable.
Fuel consumption becomes bad.
The hydraulic oil temperature calculating part is kept at
maximum.
Retrial B
Check Harness
Replace Hydraulic Oil Temperature Sensor
Replace MC
T5-5-21
TROUBLESHOOTING / Troubleshooting A
ECM1 and ECM2 FAULT CODE LIST
ECM1
Fault Code
45-3
45-3
91-0
Trouble
Presumptive Symptoms in Real Machine Operation
Abnormal High Voltage of Decompression Engine output lowering
Valve
Abnormal Low Voltage of Decompression Engine output lowering
Valve
Unadjustment of Accelertor Pedal
Differences of accelerator pedal movemant and engine
speed change may come out than usual.
91-2
Unceratin Volatage of Accelertor Pedal
91-3
Abnormal High Voltage of Accelertor Differences of accelerator pedal movemant and engine
Pedal
speed change may come out than usual.
91-4
Abnormal Low Voltage of Accelertor Differences of accelerator pedal movemant and engine
Pedal
speed change may come out than usual.
98-0
Abnormal Oil Level
The engine may be damaged.
98-1
Engine Oil Level Lowering
The engine may be damaged.
98-14
Abnormal Lowering of Engine Oil Level
100-1
100-14
110-0
110-14
158-0
158-1
Differences of accelerator pedal movemant and engine
speed change may come out than usual.
If coolant temperature is also high, the engine may stop
automatically.
Engine Oil Pressure Lowering
The engine inside is worn and the engine may be
damaged.
Abnormal Lowering of Engine Oil If coolant temperature is also high, the engine may stop
Pressure
automatically.
High Coolant Temperature
Abnormal temperature rise around engine
Engine output may be lowered.
Abnormal Rise in Coolant Temperature
Abnormal temperature rise around engine
Engine output may be lowered.
If engine oil pressure is also high, the engine may stop
automatically.
Abnormal Rise in Signal Voltage with Key The engine cannot start or engine speed control is
ON
impossible.
Signal Voltage with Key ON Lowering
The trouble may occur that the engine cannot start or the
engine stops suddenly.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-22
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Check solenoid valve
Check wiring
Check solenoid valve
Adjust accelerator pedal
Check wiring
• Operating position at Idle speed: 5 V
• Kickdown position: 4.9 V
Fault Code
(K-line)
10003
10004
10200
Check wiring
• Operating position at Idle speed: 5 V
• Kickdown position: 4.9 V
Replace accelerator pedal sensor
10202
Check wiring
• Operating position at Idle speed: 5 V
• Kickdown position: 4.9 V
Replace accelerator pedal sensor
10203
Check wiring
• Operating position at Idle speed: 5 V
• Kickdown position: 4.9 V
Replace accelerator pedal sensor
10204
Refill or drain engine oil
10400
Refill engine oil
10401
Refill oil
10414
Check engine oil pump and hydraulic circuit
10501
Check engine oil pump and hydraulic circuit
10514
Check coolant level and cooling circuit
10900
Check coolant level and cooling circuit
10914
Check battery voltage
Normal voltage at terminal #2 of connector ECM1-D: 22V-30V
Check battery voltage
Normal voltage at terminal #2 of connector ECM1-D: 22V-30V
11100
T5-5-23
11101
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
620-3
High Voltage in Accelerator Pedal Faulty connection or faulty parameter
Direct-Connected Circuit
Programing is large influence to accelerator pedal movement.
The operator’s operation may be defective (EX: Throttle back).
The operator’s operation may be slow.
620-4
Low Voltage in Accelerator Pedal Faulty connection or faulty parameter
Direct-Connected Circuit
Programing is large influence to accelerator pedal movement.
The operator’s operation may be defective (EX: Throttle
back). The operator’s operation may be slow.
625-2
Faulty CAN communication between Disabled communication between ECM1 and ECM2
ECM1 and ECM2
Open circuit in CAN High line or Low The engine system can be operated at single line mode.
line between ECM1 and ECM2
Internal error of ECM1
Any troubles occur due to internal error of ECM1.
625-14
629-12
730-0
After the in-take air heater relay is Low-temperature startability lowering
operated, temperature of the in-take
air heater does not rise.
730-1
The intake-air heater relay is not Low-temperature startability lowering
operated.
The intake-air heater relay is not Low-temperature startability lowering
operated.
High Voltage in Intake-Air Heater Low-temperature startability lowering
Relay
Low Voltage in Intake-Air Heater Low-temperature startability lowering
Relay
Abnormal CAN Communication
Different trouble occurs accroding to damage.
730-2
730-3
730-4
639-2
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-24
TROUBLESHOOTING / Troubleshooting A
Remedy
Power supply 5.2 V or higher is abnormal.
Check wiring
Fault Code
(K-line)
12103
Power supply less than 4.8 V is abnormal.
Check wiring
12104
Check wiring (engine CAN)
12202
Check wiring (engine CAN)
12214
Replace ECM1
12312
Check wiring
Check in-take heater relay
Check in-take heater
13900
Check wiring
Check in-take heater relay
Check wiring
Check in-take heater relay
Check wiring
Check in-take heater relay
Check wiring
Check in-take heater relay
Check if MC is suitabel for the machine.
Replace MC
13901
13902
13903
13904
14902
T5-5-25
TROUBLESHOOTING / Troubleshooting A
ECM2
Fault
Code
94-0
94-1
94-2
94-3
Trouble
Shorted Power Circuit
Combination Sensor
Presumptive Symptoms in Real Machine Operation
in
Fuel If abnormal sensor voltage is detected for 2 seconds or longer,
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
Uncertain Input Value of Fuel If abnormal sensor voltage is detected for 2 seconds or longer,
Combination Sensor
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
Out of Specification for Fuel If abnormal sensor voltage is detected for 2 seconds or longer,
Combination Sensor
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
Abnormal High Voltage of Fuel If abnormal sensor voltage is detected for 2 seconds or longer,
Combination Sensor
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-26
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
Fault Code
(K-line)
11715
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
11716
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
11717
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
13015
T5-5-27
TROUBLESHOOTING / Troubleshooting A
Fault
Code
94-4
94-14
98-2
Trouble
Abnormal Low Voltage
Combination Sensor
Presumptive Symptoms in Real Machine Operation
of
Fuel If abnormal sensor voltage is detected for 2 seconds or longer,
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
Uncertain Value of Fuel Combination If abnormal sensor voltage is detected for 2 seconds or longer,
Sensor
the fault code is displayed.
Specification of pressure sensor in normal time: 0 to 2 MPa (0
to 20 kgf/cm2), 0 to 5 V
Specification of temperature sensor in normal time: -40 to
+150 °C, 0 to 5 V
If trouble occurs, the engine is operated under the latest fuel
pressure and fuel temperature which are recorded as the
backup values.
Out of Specification for Engine Oil If coolant temperature is also high, the engine may stop.
Level
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-28
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
Fault Code
(K-line)
13016
Check wiring between fuel combination sensor and ECM2
Replace fuel combination sensor
11917
Check engine oil level
Check wiring (Chek if the circuit to power source is shorted.)
Check engine oil level sensor (Normal: 20 to 25 Ω)
2026
T5-5-29
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
98-2
No Reliability for Measurement of Engine If coolant temperature is also high, the engine may stop.
Oil Level Sensor
98-3
Abnormal High Voltage of Engine Oil If abnormal sensro voltage is detected for 2 seconds or
Level Sensor
longer, the fault code is displayed.
98-4
Abnormal Low Voltage of Engine Oil If abnormal sensro voltage is detected for 2 seconds or
Level Sensor
longer, the fault code is displayed.
98-5
Open Circuit in Engine Oil Level Sensor
100-2
No Reliability for Signal of Engine Oil If abnormal sensro voltage is detected for 2 seconds or
Pressure Sensor
longer, the fault code is displayed.
100-3
Abnormal High Voltage of Engine Oil If abnormal sensro voltage is detected for 2 seconds or
Pressure Sensor
longer, the fault code is displayed.
Abnormal Low Voltage of Engine Oil If abnormal sensro voltage is detected for 2 seconds or
Pressure Sensor
longer, the fault code is displayed.
100-4
100-14
102-0
102-1
102-2
102-3
102-4
105-0
105-3
105-4
110-0
If abnormal sensro voltage is detected for 2 seconds or
longer, the fault code is displayed.
Abnormal Lowering of Engine Oil Level If abnormal sensro voltage is detected for 2 seconds or
Pressure
longer, the fault code is displayed.
Abnormal High Booster Pressure
If sensro voltage is not within specification for 2 seconds
or longer, the fault code is detected.
Uncertain Input Value of Booster Pass
If sensro voltage is not within specification for 2 seconds
or longer, the fault code is detected.
No Reliability for Measurement of Boost If sensro voltage is not within specification for 2 seconds
Pressure Sensor
or longer, the fault code is detected.
Abnormal High Voltage of Boost If sensro voltage is not within specification for 2 seconds
Pressure Sensor
or longer, the fault code is detected.
Abnormal Low Voltage of Boost Pressure If sensro voltage is not within specification for 2 seconds
Sensor
or longer, the fault code is detected.
Booster Pass Overheating
Engine function is lost.
Abnormal High Voltage of Booster If sensro voltage is not within specification for 2 seconds
Tempertaure Sensor
or longer, the fault code is detected.
Abnormal Low Voltage of Booster If sensro voltage is not within specification for 2 seconds
Tempertaure Sensor
or longer, the fault code is detected.
Abnormal High Coolant Temperature of If sensro voltage is not within specification for 2 seconds
Coolant Temeperature Sensor
or longer, the fault code is detected.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-30
TROUBLESHOOTING / Troubleshooting A
Remedy
Chec engine oil level
Check wiring (Chek if the circuit to power source is shorted.)
Check engine oil level sensor (Normal: 20 to 25 Ω)
Chec engine oil level
Check wiring (Chek if the circuit to power source is shorted.)
Check engine oil level sensor (Normal: 20 to 25 Ω)
Chec engine oil level
Check wiring (Chek if the circuit to power source is shorted.)
Check engine oil level sensor (Normal: 20 to 25 Ω)
Chec engine oil level
Check wiring
Check engine oil level sensor (Normal: 20 to 25 Ω)
Chec engine oil level
Check wiring
Check engine oil pressure sensor
Check engine oil pressure sensor
Check if wiring to power source is open or shorted.
Check engine oil pressure sensor
Check wiring
Altough the engine oil pressure sensor and the wiring have no problem and if the fault code is
displayed, check the engine inside.
Altough the engine oil pressure sensor and the wiring have no problem and if the fault code is
displayed, check the engine inside.
Check in-take system
Fault Code
(K-line)
2517
2515
2516
2509
11617
11615
11616
2020
11820
Check for leakage of turbocharger, in-take line and connecting tool
Check in-take air cinditioner
Check if wiring is open or faulty.
Check in-take combination sensor
If fault code 609-12 is also displayed, replace in-take combination sensor.
Replace ECM2
11818
Check in-take pressure
Check wiring
Check wiring
Replace in-take combination sensor
Abnormal high temperature of boost pressure
Check if intercooler is clogged.
11415
Check in-take combination sensor and wiring, If necessary, replace in-take combination sensor
(Normal: 24 kΩ (equivalent to 21℃))
Check in-take combination sensor and wiring, If necessary, replace in-take combination sensor
(Normal: 24 kΩ (equivalent to 21℃))
Check in-take combination sensor and wiring, If necessary, replace in-take combination sensor
(Normal: 24 kΩ (equivalent to 21℃))
11215
11417
11416
1822
T5-5-31
11216
2122
TROUBLESHOOTING / Troubleshooting A
Fault Code
110-3
110-4
158-2
158-2
168-3
168-4
174-3
174-4
175-3
175-4
190-0
609-11
609-12
609-14
Trouble
Presumptive Symptoms in Real Machine Operation
Abnormal High Voltage of Coolant If sensro voltage is not within specification for 2 seconds or
Temperature Sensor
longer, the fault code is detected.
Within
Specification
of
Coolant If sensro voltage is not within specification for 2 seconds or
Temperature Sensor
longer, the fault code is detected.
Mismatch in Key Switch ON Signal If input values are mismatched for 2 seconds or longer, the
Input Values to ECM1 and ECM2
fault code is detected.
Mismatch in Key Switch ST Signal Input If input values are mismatched for 1 second or longer, the
Values to ECM1 and ECM2
fault code is detected.
Alternator Overvoltage
If voltage is beyond 30 V for 5 seconds or longer, the fault
code is detected.
Faulty
Electrical
Generation
of If voltage is below 22 V for 5 seconds or longer, the fault
Alternator
code is detected.
Abnormal High Voltage of Fuel If sensro voltage is not beyond specification for 2 seconds
Temperature Sensor
or longer, the fault code is detected.
Abnormal Low Voltage of Fuel If sensro voltage is not below specification for 2 seconds or
Temperature Sensor
longer, the fault code is detected.
Abnormal High Voltage of Oil If sensro voltage is not beyond specification for 2 seconds
Temperature Sensor
or longer, the fault code is detected.
Abnormal
Low
Voltage
of
Oil If sensro voltage is not below specification for 2 seconds or
Temperature Sensor
longer, the fault code is detected.
Abnormal Fast Engine Speed
When engine speed is beyond specification, the buzzer
sounds.
Faulty ECM2
Any troubles occur according to malfunction.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-32
TROUBLESHOOTING / Troubleshooting A
Remedy
Check coolant temperature sensor (Normal: 24 Ω at 21℃)
Check wiring
Check coolant temperature sensor (Normal: 24 Ω at 21℃)
Check wiring
Check fuse
Check wiring
Fault Code
(K-line)
11515
11516
12219
Check wiring
12319
Faulty alternator
Faulty governor
Check battery
Check alternator
Check fuse
Check sensor (Normal: 24 Ω at 21℃)
Check wiring
Check sensor (Normal: 24 Ω at 21℃)
Check wiring
Check sensor (Normal: 24 Ω at 21℃)
Check wiring
Check sensor (Normal: 24 Ω at 21℃)
Check wiring
Notice of recognized engine speed
Delete wrong memory
Check if the related electric parts are damaged, faulty or corrosive.
Replace ECM2
7542
T5-5-33
7543
11115
11116
1015
1016
10530
4056
1315
1316
4024
14034D
14035D
14036D
4038
14038
14039
4040
14054
18039
4037
4047
4048
14049
4050
4051
14052
24053
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
625-2
625-14
CAN Communication Error
636-1
636-8
Small Clearance When Installing Crank If abnormal value is detected for 12 seconds or longer, the
Shaft Sensor
fault code is displayed.
Abnormal High Voltage of Crank Shaft If abnormal value is detected for 12 seconds or longer, the
Sensor
fault code is displayed.
Abnormal Low Voltage of Crank Shaft If abnormal value is detected for 12 seconds or longer, the
Sensor
fault code is displayed.
No Reliability for Crank Shaft or Crank Engine speed control may be impossible.
Shaft Signal
Crank Shaft Sensor Time Out
The engine may be impossble to start.
636-14
Connection Error of Crank Shaft Sensor The engine may be impossble to start.
651-3
Abnormal High Voltage of Unit Pump Any troubles occur as for engine starting , engine stop
Power Supply Line for 1, 3, 5 Cylinders and engine speed control according to malfunction.
Abnormal High Voltage of Unit Pump Any troubles occur as for engine starting , engine stop
Power Supply Line for 2, 4, 6 Cylinders and engine speed control according to malfunction.
Abnormal Low Voltage of Unit Pump Any troubles occur as for engine starting , engine stop
Power Supply Line for 1, 3, 5 Cylinders and engine speed control according to malfunction.
Abnormal Low Voltage of Unit Pump Any troubles occur as for engine starting , engine stop
Power Supply Line for 2, 4, 6 Cylinders and engine speed control according to malfunction.
Inability to Control Unit Pump for Any troubles occur as for engine starting , engine stop
Cylinder #1
and engine speed control according to malfunction.
636-3
636-4
636-7
651-3
651-4
651-4
651-5
Any troubles occur according to malfunction.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-34
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Replace ECM2
Remove and visually inspect crank shaft sensor
Check wiring
Check crank shaft sensor (Normal: 1.2 kΩ)
Check wiring
Check crank shaft sensor (Normal: 1.2 kΩ)
Check wiring
Check crank shaft sensor (Normal: 1.2 kΩ)
While the engine stops, install the sensor completely and execute retrial.
Check crank shaft sensor (Normal: 1.2 kΩ)
Check wiring
Check crank shaft sensor (Normal: 1.2 kΩ)
Retry
Check wiring
Replace ECM2
Check wiring
Replace ECM2
Check wiring
Replace ECM2
Check wiring
Replace ECM2
Check wiring
Check injector
Check fuel line
Replace unit pump
T5-5-35
Fault Code
(K-line)
10102
10104
10100
10101
10149
10310
10309
10308
10311
10312
10313
24805
24905
24806
24906
15027
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
651-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #1
651-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #1 and Other Cylinders
The engine may not start.
651-12
Open Circuit in Unit Pump for If abnormal condition continues for 5 seconds or longer, the
Cylinder #1
fault code is detected.
651-14
Faulty Unit Pump Inside for Cylinder If abnormal condition continues for 5 seconds or longer, the
#1
fault code is detected.
652-5
Impossible to Control Unit Pump for Any troubles occur as for engine starting , engine stop and
Cylinder #2
engine speed control according to malfunction.
652-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #2
652-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #2 and Other Cylinders
The engine may not start.
652-12
Open Circuit in Unit Pump for If abnormal condition continues for 5 seconds or longer, the
Cylinder #2
fault code is detected.
652-14
Faulty Unit Pump Inside for Cylinder If abnormal condition continues for 5 seconds or longer, the
#2
fault code is detected.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-36
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Check injector
Check fuel line
Replace unit pump
Fault Code
(K-line)
25028
Check wiring
Check injector
Check fuel line
Replace unit pump
15026
Check wiring
Check injector
Check fuel line
Replace unit pump
9044
Check wiring
Check injector
Check fuel line
Replace unit pump
9045
Check wiring
Check injector
Check fuel line
Replace unit pump
Check wiring
Check injector
Check fuel line
Replace unit pump
15127
Check wiring
Check injector
Check fuel line
Replace unit pump
15126
Check wiring
Check injector
Check fuel line
Replace unit pump
9144
Check wiring
Check injector
Check fuel line
Replace unit pump
9145
25128
T5-5-37
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
653-5
Impossible to Control Unit Pump for Any troubles occur as for engine starting , engine stop and
Cylinder #3
engine speed control according to malfunction.
653-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #3
653-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #3 and Other Cylinders
The engine may not start.
653-12
Open Circuit in Unit Pump for If abnormal condition continues for 5 seconds or longer, the
Cylinder #3
fault code is detected.
653-14
Faulty Unit Pump Inside for Cylinder If abnormal condition continues for 5 seconds or longer, the
#3
fault code is detected.
654-5
Impossible to Control Unit Pump for Any troubles occur as for engine starting , engine stop and
Cylinder #4
engine speed control according to malfunction.
654-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #4
654-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #4 and Other Cylinders
The engine may not start.
654-12
Open Circuit in Unit Pump for If abnormal condition continues for 5 seconds or longer, the
Cylinder #4
fault code is detected.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-38
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Check injector
Check fuel line
Replace unit pump
Fault Code
(K-line)
15227
Check wiring
Check injector
Check fuel line
Replace unit pump
25228
Check wiring
Check injector
Check fuel line
Replace unit pump
15226
Check wiring
Check injector
Check fuel line
Replace unit pump
9244
Check wiring
Check injector
Check fuel line
Replace unit pump
Check wiring
Check injector
Check fuel line
Replace unit pump
9245
15327
Check wiring
Check injector
Check fuel line
Replace unit pump
25328
Check wiring
Check injector
Check fuel line
Replace unit pump
15326
Check wiring
Check injector
Check fuel line
Replace unit pump
9344
T5-5-39
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
654-14
Faulty Unit Pump Inside for Cylinder If abnormal condition continues for 5 seconds or longer,
#4
the fault code is detected.
655-5
Impossible to Control Unit Pump for Any troubles occur as for engine starting , engine stop and
Cylinder #5
engine speed control according to malfunction.
655-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #5
655-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #5 and Other Cylinders
The engine may not start.
655-12
Open Circuit in Unit Pump for Cylinder If abnormal condition continues for 5 seconds or longer,
#5
the fault code is detected.
655-14
Faulty Unit Pump Inside for Cylinder If abnormal condition continues for 5 seconds or longer,
#5
the fault code is detected.
656-5
Impossible to Control Unit Pump for Any troubles occur as for engine starting , engine stop and
Cylinder #6
engine speed control according to malfunction.
656-6
Shorted Circuit in Unit Pump for The related cyliner is not operated.
Cylinder #6
656-7
Shorted Circuit in Unit Pumps for The related cyliner is not operated.
Cylinder #6 and Other Cylinders
The engine may not start.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-40
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Check injector
Check fuel line
Replace unit pump
Fault Code
(K-line)
9345
Check wiring
Check injector
Check fuel line
Replace unit pump
15427
Check wiring
Check injector
Check fuel line
Replace unit pump
25428
Check wiring
Check injector
Check fuel line
Replace unit pump
15426
Check wiring
Check injector
Check fuel line
Replace unit pump
Check wiring
Check injector
Check fuel line
Replace unit pump
9444
Check wiring
Check injector
Check fuel line
Replace unit pump
15527
Check wiring
Check injector
Check fuel line
Replace unit pump
25528
Check wiring
Check injector
Check fuel line
Replace unit pump
15526
9445
T5-5-41
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
656-12
Open Circuit in Unit Pump for Cylinder #6
If abnormal condition continues for 5 seconds or
longer, the fault code is detected.
656-14
Faulty Unit Pump Inside for Cylinder #6
If abnormal condition continues for 5 seconds or
longer, the fault code is detected.
677-3
Shorted Circuit in Key Start Signal Line
The starter does not start.
677-5
Opne Circuit in Key Start Signal Line
The starter does not start.
677-6
Shorted Ground Circuit in Key Start Signal The starter does not start.
Line
677-7
Faulty Starter Starting Line
The starter does not start.
677-14
Uncertain Neutral Relay Signal
The starter does not start.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-42
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Check injector
Check fuel line
Replace unit pump
Fault Code
(K-line)
9544
Check wiring
Check injector
Check fuel line
Replace unit pump
9545
Check wiring between terminal ST in key switcn and ECM1 or ECM2
Check key switch
Replace ECM1 or ECM2
Check wiring between terminal ST in key switcn and ECM1 or ECM2
Check key switch
Replace ECM1 or ECM2
Check wiring between terminal ST in key switcn and ECM1 or ECM2
Check key switch
Replace ECM1 or ECM2
Check neutral relay
Check wiring between ECM2 and terminal S in starter
Check neutral relay
Check wiring between neutral relay and ECM2
18005
T5-5-43
18009
18008
18086
18033
TROUBLESHOOTING / Troubleshooting A
Fault Code
Trouble
Presumptive Symptoms in Real Machine Operation
723-3
Open Circuit in Cam Shaft Sensor
723-4
Shorted Ground Circuit in Cam Shaft The engine may be impossible to start.
Sensor
No Signal of Cam Shaft Positioning The engine may be impossible to start.
Sensor
723-8
723-14
The engine may be impossible to start.
Faulty Cam Shaft Sensor
The engine may be impossible to start.
CAUTION: If the same fault codes on ECM1
and ECM2 exist, this fault code is displayed
for ECM 1 on Dr.ZX. Check if this fault code is
for ECM 2 in fact.
T5-5-44
TROUBLESHOOTING / Troubleshooting A
Remedy
Check wiring
Cam shaft resistance: 1.2 kΩ
Check wiring
Cam shaft resistance: 1.2 kΩ
Check wiring
Cam shaft resistance: 1.2 kΩ
Check cam shaft sensor appearance
Check wiring
Cam shaft resistance: 1.2 kΩ
Check cam shaft sensor appearance
Fault Code
(K-line)
10409
10408
10412
10413
T5-5-45
TROUBLESHOOTING/ Troubleshooting A
ICF FAULT CODE LIST
Fault Code
14000-2
14001-2
Trouble
Cause
Abnormal CAN Communication
Data cannot be received due to the noise on the CAN bus
line.
ICF: Flash Memory: Read / Write In case the internal memory is abnormal when the key is
Error
turned ON
14002-2
ICF: External RAM: Read / Write In case the internal memory is abnormal when the key is
Error
turned ON
14003-2
ICF: EEPROM: Sum Check Error
14006-2
14008-2
In case the internal memory is abnormal when the key is
turned ON
ICF:
Satellite
Communication In case communication to the satellite terminal cannot be
Terminal: Communication Error
done over 30 seconds.
ICF: Abnormal Internal RAM
In case the internal memory is abnormal when the key is
turned ON
T5-5-46
TROUBLESHOOTING/ Troubleshooting A
Remedy
If trouble is not resolved after retrial B, check for CAN communication bus line.
After initializing the information C/U by using Dr. ZX, re-try in the troubleshooting.
If the error code is displayed after re-try, ICF may be broken.
Replace ICF.
NOTE: When initialising the information C/U, all stored data is deleted.
After initializing the information C/U by using Dr. ZX, re-try in the troubleshooting.
If the error code is displayed after re-try, ICF may be broken.
Replace ICF.
NOTE: When initialising the information C/U, all stored data is deleted.
If trouble is not resolved after retrial B, ICF may be broken. Replace ICF.
Check for the items below.
1. Retrial B.
2. Check if the communication line is abnormal.
3. Check if the electrical power source of communication terminal is abnormal.
• Electrical power source
• Fuses
3. Check if the satellite terminal is broken.
Re-try in the troubleshooting by using Dr.ZX.
If the error code is displayed after re-try, ICF may be broken. Replace ICF.
T5-5-47
TROUBLESHOOTING/ Troubleshooting A
SATELLITE TERMINAL FAULT CODE LIST
Fault Code
14100-2
14101-2
14102-2
Trouble
Cause
Satellite Communication Terminal: In case internal memory is abnormal
Abnormal EEPROM
Satellite Communication Terminal: In case internal memory is abnormal
Abnormal IB/OB Queue
Satellite Communication Terminal: In case data cannot be received from the satellite terminal
Abnormal Local Loup Back
14103-2
Satellite Communication Terminal: In case the satellite terminal cannot be acquired
The satellite is not found.
14104-2
Satellite Communication Terminal: In case communication to the satellite terminal base cannot
Fail 1 of Remote Loup Back
be done
Satellite Communication Terminal: In case communication to the satellite terminal base cannot
Fail 2 of Remote Loup Back
be done
Satellite Communication Terminal: In case sending and receiving data are unmatched
Sending and receiving data are
unmatched.
14105-2
14106-2
T5-5-48
TROUBLESHOOTING/ Troubleshooting A
Remedy
Retrial B.
Replace the ICF controller.
Retrial B.
Replace the ICF controller.
Retrial B.
Check the communication aerial.
Replace the ICF controller.
Retrial B.
Check the communication aerial.
Replace the ICF controller.
Retrial B.
Replace the ICF controller.
Retrial B.
Replace the ICF controller.
Retrial B.
Replace the ICF controller.
T5-5-49
TROUBLESHOOTING/ Troubleshooting A
MONITOR UNIT FAULT CODE LIST
Fault Code
13306-2
13308-2
13312-2
13314-3
13314-4
13334-2
Trouble
Cause
Abnormal EEPROM
When failure reading EEPROM occurs
Abnormal CAN Communication
Bus off occurs beyond five times
Abnormal
Transmission
Oil Shorted ground circuit in the transmission oil temperature
Temperature Sensor
sensor
Service Brake Pressure Sensor High Voltage at the signal line in service brake pressure sensor:
Voltage
4.75 V or higher
Service Brake Pressure Sensor Low Voltage at the signal line in service brake pressure sensor:
Voltage
0.25 or less
Radiator
Coolant
Temperature Shorted ground circuit in coolant temperature sensor
Receive Error
T5-5-50
TROUBLESHOOTING / Troubleshooting A
CONTROLLER HARDWARE FAILURE
MC FAULT CODES 11000 to 11002
Fault Code
11000-2
11001-2
11002-2
Trouble
Abnormal EEPROM
Abnormal RAM
Abnormal A/D Converter
Cause
Faulty MC
Faulty MC
Faulty MC
YES
Influenced Control
All Control
All Control
All Control
*Normal.
Check if operation of machine
is normal.
Faulty MC.
NO
* When the fault code is displayed in the result of
retrial and If operation of engine or machine is
normal, the machine can be used.
T5-5-51
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11003
Fault Code
11003-3
Trouble
Abnormal Sensor Voltage
Cause
Shorted circuit in harness
Faulty sensor
Faulty MC
Influenced Control
All Control
YES
Disconnect connectors of
all sensors corresponding
to the displayed fault code
and connector monitor-1B
in monitor unit. Retry.
Check if fault code
11003-3 disappears.
NO
Faulty any sensors.
Disconnect all connectors at
MC end.
Check for continuity
between terminals #1 and
#3 of harness end
connector of each sensor to
MC, terminal #1 and vehicle
frame.
Check for continuity
between terminals #27 and
#32 of connector
monitor-1B in monitor unit,
each terminal #27, #28,
#29, #30 or #31 and vehicle
frame.
YES
Shorted circuit in harness with
continuity.
Faulty MC or faulty monitor
unit.
NO
· Key switch: OFF
Connector (Harness end of connector viewed from the
open end side)
• Parking Brake Pressure Sensor
1
2
• Pump Delivery Pressure Sensor
• Implement Pressure Sensor
3
3
Monitor Unit
Connector Monitor-1B
(Harness end)
#27
#28
T4GB-05-05-002
#32 #31 #30 #29
T5-5-52
2
1
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11004
Fault Code
11004-2
Trouble
Cause
Abnormal
CAN Shorted
circuit
Communication
harness
Faulty MC
in
Influenced Control
• All Pump Control
• All Transmission Control
• All Engine Control
• Hydraulic Drive Fan Cooling Control
• Ride Control
• CAN Cycle Data Communication
GPS
Monitor Unit
Dr-ZX
ICF
ECM1
CAN Harness
MC
ECM2
T5-5-53
TROUBLESHOOTING / Troubleshooting A
CAN HARNESS CHECK
• Check the wiring connections first.
NO
YES Check for continuity in
CAN harness between
MC and ECM1.
YES
· Key switch: OFF
· Refer to “CAN
Harness Continuity
Check” on T5-5-58.
Check for continuity in
CAN harness between
MC and ICF.
· Key switch: OFF
· Refer to “CAN
Harness Continuity
Check” on T5-5-59.
Retry by using Dr. ZX.
Check if fault code
11004-2 is displayed.
NO
Open circuit in CAN
harness between MC and
ECM1.
Check for continuity
in CAN harness
YES between MC and
monitor unit.
· Key Switch: OFF
· Refer to “CAN
Harness Continuity
Check” on T5-5-60.
Open circuit in CAN
harness between MC and
ICF.
Normal.
NO
IMPORTANT: If the CAN harness is completely
opened in circuit, the controller
name is not displayed on the
diagnosing screen on Dr. ZX (refer to
T5-2-4).
T5-5-54
TROUBLESHOOTING / Troubleshooting A
Shorted circuit in CAN
harness between ground
circuit and CAN circuit.
YES
YES
Disconnect all
connectors in MC,
ICF, ECM1 and
monitor unit.
Check for continuity
between CAN circuit
and ground circuit in
MC, ICF, ECM1 and
monitor unit.
· Key switch: OFF
· Refer to “Discontinuity
Check between CAN
Circuit and Ground
Circuit” on T5-5-61 to
65.
To A
NO
Open circuit in CAN
harness between MC and
monitor unit.
NO
Shorted circuit in CAN
harness between power
circuit and CAN circuit.
YES
A
Check for continuity
between CAN circuit
and power circuit in
MC, ICF, ECM1 and
monitor unit.
· Key switch: OFF
· Refer to “Discontinuity
Check between CAN
Circuit and Power
Circuit” on T5-5-66 to
69.
NO
T5-5-55
Check for continuity
between CAN circuit
and key signal circuit
in MC, ICF, ECM1
and monitor unit.
YES Shorted circuit in CAN
harness between key signal
circuit and CAN circuit.
NO
· Key switch: OFF
· Refer to “Discontinuity
Check between CAN
Circuit and Key Signal
Circuit” on T5-5-70 to
72.
Check for continuity
between High side
and Low side in CAN
harness.
· Key switch: OFF
· Refer to
“Discontinuity Check
in CAN Harness on
T5-5-73.
To B
TROUBLESHOOTING / Troubleshooting A
Shorted circuit in
CAN harness.
YES
B
Connect connector
YES in MC.
Check if fault code
11004-2 is
displayed.
Connect all
connectors except
connector MC-C in
MC.
Check if resistance
between terminals
#C4 and #C15 of
NO harness end of
connector MC-C is
within 60±10 Ω.
· Key switch: ON
· Key switch: OFF
NO
Connect connector in
MC. Disconnect
connector ICF-C in
ICF.
Check if resistance
between terminals
#C5 and #C11 of
harness end of
connector is within
60±10 Ω.
Faulty MC.
YES
YES
NO
MC
Connector MC-C
(Harness end)
#C4
#C15
C1
C23
Connect connector
in ICF.
Check if fault code
11004-2 is
displayed.
· Key switch: ON
· Key switch: OFF
Connector
Check the
connection of MC
and connector.
NO
Connect connector in
ICF.
Disconnect
connector ECM1-D in
ECM1.
Check if resistance
between terminals
#D19 and #D21 of
harness end of
connector is within
60±10 Ω.
NO
Check the
connection of ICF
and connector.
Faulty ICF.
YES
YES
Connect connector
in ECM1.
Check if fault code
11004-2 is
displayed.
· Key switch: ON
NO
· Key switch: OFF
C10
C31
Connect connector in
ECM1.
Disconnect
connector monitor-2B
in monitor unit.
Check if resistance
between terminals
#33 and #34 of
harness end of
connector is within
120±10 Ω.
· Key switch: OFF
ICF
Connector ICF-C
(Harness end)
#C5
#C11
T1V1-05-04-002
ECM1
Connector ECM1-D
(Harness end)
Monitor Unit
Connector Monitor-2B
(Harness end)
#D19
T4GB-05-05-002
#D21
#34
T5-5-56
#33
TROUBLESHOOTING / Troubleshooting A
Check the connection of
ECM and connector.
NO
Faulty ECM1 or 2.
YES
YES
Connect connector in
monitor unit.
Check if fault code
11004-2 is displayed.
· Key switch: ON
NO
Check the connection of
monitor unit and
connector.
Faulty monitor unit.
YES
Failure in any controller
of MC, ICF, ECM1,
ECM2 and monitor unit.
T5-5-57
TROUBLESHOOTING / Troubleshooting A
Continuity Check in CAN Harness
IMPORTANT: Before continuity check, turn the key
switch OFF.
• Between MC and ECM1
CAN Harness (High Side)
Check for continuity between terminal #C4 of
harness end of connector MC-C in MC and
terminal #D19 of harness end of connector
ECM1-D in ECM1.
CAN Harness (Low Side)
Check for continuity between terminal #C15 of
harness end of connector MC-C in MC and
terminal #D21 of harness end of connector
ECM1-D in ECM1.
Connector
MC
Connector MC-C
(Harness end)
#C4
#C15
C1
C23
C10
C31
ECM1
Connector ECM1-D
(Harness end)
#D19
•
#D21
T5-5-58
TROUBLESHOOTING / Troubleshooting A
Between MC and ICF
CAN Harness (High Side)
Check for continuity between terminal #C4 of
harness end of connector MC-C in MC and
terminal #C5 of harness end of connector ICF-C
in ICF.
CAN Harness (Low Side)
Check for continuity between terminal #C15 of
harness end of connector MC-C in MC and
terminal #C11 of harness end of connector ICF-C
in ICF.
Connector
MC
Connector MC-C
(Harness end)
#C4
#C15
C10
C1
C23
C31
ICF
Connector ICF-C
(Harness end)
#C5
#C11
T1V1-05-04-002
T5-5-59
TROUBLESHOOTING / Troubleshooting A
• Between MC and Monitor Unit
CAN Harness (High Side)
Check for continuity between terminal #C4 of
harness end of connector MC-C in MC and
terminal #33 of harness end of connector
monitor-2B in the monitor unit.
CAN Harness (Low Side)
Check for continuity between terminal #C15 of
harness end of connector MC-C in MC and
terminal #34 of harness end of connector
monitor-2B in the monitor unit.
Connector
MC
Connector MC-C
(Harness end)
#C4
#C15
C10
C1
C23
C31
Monitor Unit
Connector Monitor-2B
(Harness end)
T4GB-05-05-002
#34
#33
T5-5-60
TROUBLESHOOTING / Troubleshooting A
Discontinuity Check between CAN Circuit and
Ground Circuit
IMPORTANT: Before continuity check, turn the key
switch OFF.
• In case of continuity, the circuit
between CAN circuit and ground
circuit is shorted.
• In case of discontinuity, the circuit is
normal.
Connector
Connector MC-C
(Harness end)
#C4
C10
C1
C23
• MC
Between CAN Circuit (High Side) and Ground
Circuit
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal #A2
of harness end of connector in MC-A.
C31
Connector MC-A
(Harness end)
#A2
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal
#A13 of harness end of connector in MC-A.
#A13
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal #B8
of harness end of connector in MC-B.
T183-05-04-008
Connector MC-B
(Harness end)
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal
#B18 of harness end of connector in MC-B.
#B8
#B18
T183-05-04-021
T5-5-61
TROUBLESHOOTING / Troubleshooting A
Between CAN Circuit (Low Side) and Ground
Circuit
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal #A2
of harness end of connector in MC-A.
Connector
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal
#A13 of harness end of connector in MC-A.
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal #B8
of harness end of connector in MC-B.
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal
#B18 of harness end of connector in MC-B.
Connector MC-C
(Harness end)
#C15
C10
C1
C23
C31
Connector MC-A
(Harness end)
#A2
#A13
T183-05-04-008
Connector MC-B
(Harness end)
#B8
#B18
T183-05-04-021
T5-5-62
TROUBLESHOOTING / Troubleshooting A
• ECM1
Between CAN Circuit (High Side) and Ground
Circuit
Check for continuity between terminals #D19 and
#D3 of harness end of connector ECM1-D.
Check for continuity between terminals #D19 and
#D14 of harness end of connector ECM1-D.
ECM1
Connector ECM1-D
(Harness end)
#D19
#D3
Between CAN Circuit (Low Side) and Ground
Circuit
Check for continuity between terminals #D21 and
#D3 of harness end of connector ECM1-D.
Check for continuity between terminals #D21 and
#D14 of harness end of connector ECM1-D.
#D14
ECM1
Connector ECM1-D
(Harness end)
#D3
#D21
T5-5-63
#D14
TROUBLESHOOTING / Troubleshooting A
• ICF
Between CAN Circuit (High Side) and Ground
Circuit
ICF
Connector ICF-C
(Harness end)
Check for continuity between terminals #C5 and
#C9 of harness end of connector ICF-C.
#C5
Check for continuity between terminals #C5 and
#C14 of harness end of connector ICF-C.
Check for continuity between terminals #C5 and
#C15 of harness end of connector ICF-C.
#C14
Between CAN Circuit (Low Side) and Ground
Circuit
ICF
Connector ICF-C
(Harness end)
#C15
Check for continuity between terminals #C11 and
#C15 of harness end of connector ICF-C.
T5-5-64
T1V1-05-04-002
#C9
Check for continuity between terminals #C11 and
#C9 of harness end of connector ICF-C.
Check for continuity between terminals #C11 and
#C14 of harness end of connector ICF-C.
#C9
#C14
#C15
#C11
T1V1-05-04-002
TROUBLESHOOTING / Troubleshooting A
• Monitor Unit
Between CAN Circuit (High Side) and Ground
Circuit
Check for continuity between terminal #33 of
harness end of connector monitor-2B and terminal
#19 of harness end of connector monitor-2A in the
monitor unit.
Check for continuity between terminal #33 of
harness end of connector monitor-2B and terminal
#4 of harness end of connector monitor-1A in the
monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
T4GB-05-05-002
#33
Monitor Unit
Connector Monitor-2A
(Harness end)
T183-05-04-013
#19
Monitor Unit
Connector Monitor-1A
(Harness end)
#4
T183-05-04-013
Between CAN Circuit (Low Side) and Ground
Circuit
Check for continuity between terminal #34 of
harness end of connector monitor-2B and terminal
#19 of harness end of connector monitor-2A in the
monitor unit.
Check for continuity between terminal #34 of
harness end of connector monitor-2B and terminal
#4 of harness end of connector monitor-1A in the
monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
T4GB-05-05-002
#34
Monitor Unit
Connector Monitor-2A
(Harness end)
T183-05-04-013
#19
Monitor Unit
Connector Monitor-1A
(Harness end)
#4
T183-05-04-013
T5-5-65
TROUBLESHOOTING / Troubleshooting A
Discontinuity Check between CAN Circuit and
Power Circuit
Connector
IMPORTANT: Before continuity check, turn the key
switch OFF.
• In case of continuity, the circuit
between CAN circuit and power
circuit is shorted.
• In case of discontinuity, the circuit is
normal.
Connector MC-C
(Harness end)
#C4
C1
C23
C10
C31
• MC
Between CAN Circuit (High Side) and Power
Circuit
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal #A1
of harness end connector MC-A.
#A1
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal
#A12 of harness end connector MC-A.
#A12
Connector MC-A
(Harness end)
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal #B7
of harness end connector MC-B.
T183-05-04-008
Connector MC-B
(Harness end)
#B7
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal
#B17 of harness end connector MC-B.
#B17
T183-05-04-021
T5-5-66
TROUBLESHOOTING / Troubleshooting A
Between CAN Circuit (Low Side) and Power
Circuit
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal #A2
of harness end connector MC-A.
Connector
Connector MC-C
(Harness end)
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal
#A12 of harness end connector MC-A.
C1
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal #B7
of harness end connector MC-B.
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal
#B17 of harness end connector MC-B.
C23
#C15
C10
C31
Connector MC-A
(Harness end)
#A1
#A12
T183-05-04-008
Connector MC-B
(Harness end)
#B7
#B17
T183-05-04-021
T5-5-67
TROUBLESHOOTING / Troubleshooting A
• ECM1
Between CAN Circuit (High Side) and Power
Circuit
Check for continuity between terminals #D19 and
#D1 of harness end of connector ECM1-D.
Between CAN Circuit (Low Side) and Power
Circuit
Check for continuity between terminals #D21 and
#D1 of harness end of connector ECM1-D.
ECM1
Connector
(Harness end)
#D1
#D19
ECM1
Connector ECM1-D
(Harness end)
#D1
#D21
• ICF
Between CAN Circuit (High Side) and Power
Circuit
Check for continuity between terminals #C5 and
#C1 of harness end of connector ICF-C.
ICF
Connector ICF-C
(Harness end)
#C2
#C5
#C1
Check for continuity between terminals #C5 and
#C2 of harness end of connector ICF-C.
T1V1-05-04-002
Between CAN Circuit (Low Side) and Power
Circuit
Check for continuity between terminals #C11 and
#C1 of harness end of connector ICF-C.
ICF
Connector ICF-C
(Harness end)
Check for continuity between terminals #C11 and
#C2 of harness end of connector ICF-C.
#C1
#C2
#C11
T5-5-68
T1V1-05-04-002
TROUBLESHOOTING / Troubleshooting A
• Monitor Unit
Between CAN Circuit (High Side) and Power
Circuit
Check for continuity between terminal #33 of
harness end of connector monitor–2B in the
monitor unit and terminal #1 of harness end of
connector monitor–1A in the monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
#33
T4GB-05-05-002
Monitor Unit
Connector Monitor-1A
(Harness end)
#1
T183-05-04-013
Between CAN Circuit (Low Side) and Power
Circuit
Check for continuity between terminal #34 of
harness end of connector monitor–2B in the
monitor unit and terminal #1 of harness end of
connector monitor–1A in the monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
#34
T4GB-05-05-002
Monitor Unit
Connector Monitor-1A
(Harness end)
#1
T183-05-04-013
T5-5-69
TROUBLESHOOTING / Troubleshooting A
Discontinuity Check between CAN Circuit and
Key Signal Circuit
Connector
IMPORTANT: Before continuity check, turn the key
switch OFF.
• In case of continuity, the circuit
between CAN circuit and key signal
circuit is shorted.
• In case of discontinuity, the circuit is
normal.
Connector MC-C
(Harness end)
#C4
C10
C1
C23
• MC
Between CAN Circuit (High Side) and Key Signal
Circuit
Check for continuity between terminal #C4 of
harness end of connector MC-C and terminal
#B16 of harness end of connector MC-B.
C31
Connector MC-B
(Harness end)
#B16
T183-05-04-021
Between CAN Circuit (Low Side) and Key Signal
Circuit
Check for continuity between terminal #C15 of
harness end of connector MC-C and terminal
#B16 of harness end of connector MC-B.
Connector
Connector MC-C
(Harness end)
#C15
C1
C23
C10
C31
Connector MC-B
(Harness end)
#B16
T183-05-04-021
T5-5-70
TROUBLESHOOTING / Troubleshooting A
• ECM1
Between CAN Circuit (High Side) and Key Signal
Circuit
Check for continuity between terminals #D19 and
#24 of harness end of connector ECM1-D.
ECM1
Connector ECM1-D
(Harness end)
#D19
#D2
Between CAN Circuit (Low Side) and Key Signal
Circuit
Check for continuity between terminals #D21 and
#24 of harness end of connector ECM1-D.
ECM1
Connector ECM1-D
(Harness end)
#D2
#D21
• ICF
Between CAN Circuit (High Side) and Key Signal
Circuit
Check for continuity between terminals #C5 and
#C7 of harness end of connector ICF-C.
ICF
Connector ICF-C
(Harness end)
#C5
#C7
T1V1-05-04-002
Between CAN Circuit (Low Side) and Key Signal
Circuit
Check for continuity between terminals #C11 and
#C7 of harness end of connector ICF-C.
ICF
Connector ICF-C
(Harness end)
#C7
#C11
T5-5-71
T1V1-05-04-002
TROUBLESHOOTING / Troubleshooting A
• Monitor Unit
Between CAN Circuit (High Side) and Key Signal
Circuit
Check for continuity between terminal #33 of
harness end of connector monitor–2B in the
monitor unit and terminal #2 of harness end of
connector monitor–1A in the monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
T4GB-05-05-002
#33
Monitor Unit
Connector Monitor-1A
(Harness end)
#2
T183-05-04-013
Between CAN Circuit (Low Side) and Key Signal
Circuit
Check for continuity between terminal #34 of
harness end of connector monitor–2B in the
monitor unit and terminal #2 of harness end of
connector monitor–1A in the monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
T4GB-05-05-002
#34
Monitor Unit
Connector Monitor-1A
(Harness end)
#2
T183-05-04-013
T5-5-72
TROUBLESHOOTING / Troubleshooting A
Discontinuity Check in CAN Harness
IMPORTANT: Before continuity check, turn the key
switch OFF.
• In case of continuity, the circuit
between CAN (high side) circuit and
CAN (low side) circuit is shorted.
• In case of discontinuity, the circuit is
normal.
• Connector MC-C
MC
Connector MC-C
(Harness end)
Check for continuity between terminals #C4 and
#C15 of harness end of connector MC-C in MC.
#C4
C1
C23
• Connector ECM1-D in ECM1
Check for continuity between terminals #D19 and
#D21 of harness end of connector ECM1-D in
ECM1.
ECM1
Connector ECM1-D
(Harness end)
#D19
#D21
T5-5-73
#C15
C10
C31
TROUBLESHOOTING / Troubleshooting A
• Connector ICF-C
Check for continuity between terminals #C5 and
#C11 of harness end of connector ICF-C in ICF.
ICF
Connector ICF-C
(Harness end)
#C5
#C11
• Connector Monitor-2B in Monitor Unit
Check for continuity between terminals #B33 and
#B34 of harness end of connector monitor-2B in
the monitor unit.
Monitor Unit
Connector Monitor-2B
(Harness end)
#B34 #B33
T5-5-74
T1V1-05-04-002
T4GB-05-05-002
TROUBLESHOOTING / Troubleshooting A
ENGINE FAILURE
MC FAULT CODE 11103
Fault Code
Trouble
Cause
11103-3 Abnormal Accelerator Pedal Voltage: 4.75 V or higher
High Voltage
11103-4
Abnormal Accelerator Pedal Voltage: Less than 0.25 V
Low Voltage
Influenced Control
Pump
Torque
Decrease
Control
Engine Accelerator Pedal
Control
Pump
Torque
Decrease
Control
Engine Accelerator Pedal
Control
Open circuit in
harness between MC
and accelerator pedal
sensor (terminal #1).
NO
Disconnect connector
MC-C in MC.
Check for continuity
between terminal #C13
YES of harness end of
connector and terminal
#1 of harness end of
connector in
accelerator pedal
sensor.
Check if voltage between
terminals #2 and #6 of
harness end of connector
in accelerator pedal sensor
is 5±0.5 V.
Check if voltage
between terminal #2 of
harness end of
connector in
accelerator pedal
NO
sensor and vehicle
frame is specigication.
· Key switch: ON
With connector of
accelerator pedal sensor
connected, insert a tester YES Faulty MC.
probe into rear of
connector of terminal #1.
Operate accelerator
YES pedal.
Faulty accelerator
Check if voltage reaches
pedal sensor.
specification.
NO
· Key switch: ON
Open circuit in
YES
· Specification: Refer to
harness between MC
the table below.
and accelerator pedal
sensor (terminal #6).
· Key switch: ON
· Specification: 5±0.5 V
Specification of Accelerator Pedal Sensor
Slow Idle
0.5 to 0.65 V
Fast Idle
4.35 to 4.5 V
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#C13
C10
C1
C23
C31
Accelerator Pedal Sensor Connector
#2
#1
4
1
8
5
#6
T5-5-75
NO
Open circuit in
harness between MC
and accelerator pedal
sensor (terminal #2).
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11105
Fault Code
11105-3
Trouble
Cause
Influenced Control
Abnormal Torque Converter Engine speed=0 min-1
• Hydraulic rive Fan Cooling
Input Shaft Sensor
ECM1 engine speed>500
Control
min-1
Replace torque
converter input shaft
sensor. Start engine in
10 seconds after key
switch is turned OFF.
Travel machine 20 m.
Retry.
Check if fault code
disappears.
· Key switch: ON
Check if voltage
between terminals #1
NO of harness end of
connector in torque
converter input shaft
sensor and vehicle
frame is 5±0.5 V.
· Key switch: ON
Disconnect connector
MC-C in MC.
Check for continuity
between terminal #C16
YES of harness end of
connector and terminal
#2 of harness end of
connector in torque
converter input shaft
sensor.
NO
Disconnect connector
MC-C in MC.
Check for continuity
between terminal #C5
of harness end of
connector and terminal
#1 of harness end of
connector in torque
converter input shaft
sensor.
YES
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#C5
C10
C1
C23
C31
#C16
Torque Converter Input
Shaft Sensor Connector
#1
#2
T5-5-76
NO
Open circuit in hranees
between MC and torque
converter input shaft
sensor (terminal #2).
Faulty MC.
YES
YES Faulty MC.
NO
Open circuit in hranees
between MC and torque
converter input shaft
sensor (terminal #1).
Faulty MC and torque
converter input shaft
sensor.
TROUBLESHOOTING / Troubleshooting A
PUMP FAILURE
MC FAULT CODE 11204
Fault Code
11204-3
11204-4
Trouble
Cause
Influenced Control
Abnormal
Pump
Delivery Output voltage: 4.75 V or • Pump
Torque
Decrease
Pressure Sensor High Voltage higher
Control: Disabled
Abnormal
Pump
Delivery Output voltage: Less than 0.25 • Pump
Torque
Decrease
Pressure Sensor Low Voltage V
Control: Disabled
Switch pump delivery
pressure sensor with
normal pressure sensor
and retry.
Check if fault code
disappears.
Disconnect connector
MC-C in MC. Check for
continuity between
terminal #C2 of
YES harness end of
connector and terminal
#2 of harness end of
connector in pump
delivery pressure
sensor.
Disconnect connector
of pump delivery
pressure sensor.
NO Check if voltage
between terminals #1
and #3 of harness end
of connector is 5±0.5
V.
· Key switch: ON.
Check if voltage
between terminal #1 of
harness end of
connector in pump
delivery pressure
sensor and vehicle
frame is specification.
· Key switch: ON
· Specification: 5±0.5 V.
NO
Connector (Harness end of connector viewed from
the open end side)
Pump Delivery
Pressure Sensor
#C2
C1
C10
3
C23
Open circuit in harnees
between MC and pump
delivery pressure sensor.
Faulty MC.
YES
YES Open circuit in harness
between MC and pump
delivery pressure sensor
(terminal #3).
NO
Open circuit in harness
between MC and pump
delivery pressure sensor
(terminal #1).
Faulty pump delivery
pressure sensor.
YES
MC
Connector MC-C
NO
2
1
C31
T5-5-77
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11209
Fault Code
11209-3
11209-4
Trouble
Cause
Influenced Control
Abnormal Implement Pressure Output voltage: 4.75 V or • Pump
Torque
Decrease
Sensor High Voltage
higher
Control: Disabled
Abnormal Implement Pressure Output voltage: Less than 0.25 • Pump
Torque
Decrease
Sensor Low Voltage
V
Control: Disabled
Disconnect connector
MC-C in MC.
Check for continuity
YES between terminal #C12
of harness end of
connector and terminal
#2 of harness end of
connector in implement
pressure sensor.
Disconnect connector
of implement pressure
sensor.
Check if voltage
NO
between terminals #1
and #3 of harness end
of connector is 5±0.5
V.
Switch implement
pressure sensor with
normal pressure sensor
and retry.
Check if fault code
disappears.
· Key switch: ON
NO
Check if voltage
between terminal #1 of
harness end of
connector in implement
pressure sensor and
vehicle frame is
specification.
· Key switch: ON
· Specification: 5±0.5 V
Connector (Harness end of connector viewed from the
open end side)
Implement
Pressure Sensor Connector
#C12
C1
C10
3
C23
Open circuit in harnees
between MC and
implement pressure
sensor.
Faulty MC.
YES
YES Open circuit in harness
between MC and
implement pressure
sensor (terminal #3).
NO
Open circuit in harness
between MC and
implement pressure
sensor (terminal #1).
Faulty implement
pressure sensor.
YES
MC
Connector MC-C
NO
2
1
C31
T5-5-78
TROUBLESHOOTING / Troubleshooting A
PILOT FAILURE
MC FAULT CODE 11312
Fault Code
11312-3
11312-4
Trouble
Cause
Abnormal
Brake
Pedal Voltage: 4.75 V or higher
Pressure Sensor (Service
Brake Pressure Sensor) High
Voltage
Abnormal
Brake
Pedal Voltage: Less than 0.25 V
Pressure Sensor (Service
Brake Pressure Sensor) Low
Voltage
• Clutch Cut-Off Control
Disconnect connector
MC-C in MC.
Check for continuity
YES between terminal #C1
of harness end of
connector and terminal
#2 of harness end of
connector in pressure
sensor.
Disconnect connector
of pressure sensor.
Check if voltage
between terminals #1
and #3 of harness end
of connector is 5±0.5
V.
NO
Influenced Control
• Clutch Cut-Off Control
· Key switch: ON
Check if voltage
between terminal #1
of harness end of
NO connector in pressure
sensor and vehicle
frame is specification.
· Key switch: ON
· Specification: 5±0.5 V
Switch pressure sensor
with normal pressure
sensor and retry.
Check if fault code
disappears.
NO
Open circuit in harness
between MC and
pressure sensor.
Faulty MC.
YES
Open circuit in harness
YES between MC and
pressure sensor (terminal
#3).
Open circuit in harness
between MC and
NO pressure sensor (terminal
#1).
Faulty pressure sensor.
YES
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
C1
Service Brake Pressure
Sensor Connector
C10
1
#C1
C23
2
3
C31
T5-5-79
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11313
Fault Code
11313-3
11313-4
Trouble
Cause
Influenced Control
Abnormal
Parking
Brake Output voltage: 4.75 V or • Parking Brake Indicator Control
Pressure Sensor High Voltage higher
Abnormal
Parking
Brake Output voltage: Less than 0.25 • Parking Brake Indicator Control
Pressure Sensor Low Voltage V
Disconnect connector
MC-C in MC.
Check for continuity
YES between terminal #C23
of harness end of
connector and terminal
#2 of harness end of
connector in pressure
sensor.
Disconnect connector
of pressure sensor.
Check if voltage
between terminals #1
NO and #3 of harness end
of connector is 5±0.5
V.
· Key switch: ON
Check if voltage
between terminal #1
of harness end of
NO connector in pressure
sensor and vehicle
frame is specification.
· Key switch: ON
· Specification: 5±0.5 V
Switch pressure sensor
with normal pressure
sensor and retry.
Check if fault code
disappears.
NO
Open circuit in harnees
between MC and
pressure sensor.
Faulty MC.
YES
Open circuit in harness
YES between MC and
pressure sensor (terminal
#3).
Open circuit in harness
between MC and
NO pressure sensor (terminal
#1).
Faulty pressure sensor.
YES
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
C1
Parking Brake Pressure
Sensor Connector
C10
1
C23
2
3
C31
#C23
T5-5-80
TROUBLESHOOTING / Troubleshooting A
PROPORTIONAL SOLENOID VALVE FAILURE
MC FAULT CODE 11412
Fault Code
11412-2
11412-3
11412-4
Trouble
Cause
Influenced Control
Abnormal Feedback of Hydraulic The feedback current to MC Hydraulic Drive Fan Cooling
Drive Fan Flow Rate Control becomes the uncertain value. Control
Solenoid Valve
Abnormal
Feedback
High The feedback current to MC is Hydraulic Drive Fan Cooling
Current of Hydraulic Drive Fan beyond the upper limit.
Control
Flow Rate Control Solenoid
Valve
Abnormal
Feedback
Low While the command from MC Hydraulic Drive Fan Cooling
Current of Hydraulic Drive Fan is output, the feedback current Control
Flow Rate Control Solenoid to MC is 56 mA or less.
Valve
YES
Check for continuity in
harness between MC
and hydraulic drive fan
flow rate control
solenoid valve.
· Between terminal #A32
of connector MC-A in
MC and terminal #1 of
connector in hydraulic
drive fan flow rate
control solenoid valve
· Between terminal #A29
of connector MC-A in
MC and terminal #2 of
connector in hydraulic
drive fan flow rate
control solenoid valve
Switch connectors of
hydraulic drive fan flow
rate control solenoid
valve and normal
solenoid valve.
Retry.
Check if fault code
disappears.
NO
Faulty hydraulic drive fan
flow rate control solenoid
valve.
Faulty MC.
YES
Open circuit in harness.
NO
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-A
#A32
#A29
T183-05-04-008
Hydraulic Drive Fan Flow Rate
Control Solenoid Valve Connector
1
2
T5-5-81
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11413
Fault Code
11413-2
11413-3
11413-4
Trouble
Cause
Influenced Control
Abnormal Feedback of Pump The feedback current to MC • Pump Standard Torque Control
Torque Control Solenoid Valve becomes the uncertain value.
Abnormal Feedback High The feedback current to MC is • Pump Standard Torque Control
Current of Pump Torque beyond the upper limit.
Control Solenoid Valve
Abnormal
Feedback
Low While the command from MC • Pump Standard Torque Control
Current of Pump Torque is output, the feedback current
Control Solenoid Valve
to MC is 56 mA or less.
YES
Check for continuity in
harness between MC
and pump torque
control solenoid valve.
· Between terminal #A31
of connector MC-A in
MC and terminal #1 of
connector in pump
torque control solenoid
valve
· Between terminal #A5
of connector MC-A in
MC and terminal #2 of
connector in pump
torque control solenoid
valve
Switch connectors of
pump torque control
solenoid valve and normal
solenoid valve.
Retry.
Check if fault code
disappears.
Faulty pump torque
control solenoid valve.
Faulty MC.
YES
Open circuit in harness.
NO
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-A
#A5
#A31
T183-05-04-008
Pump Torque Control Solenoid Valve
1
NO
2
T5-5-82
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODES 11414, 11415, 11416, 11417, 11418, 11419
Fault Code
11414-2
11414-3
11414-4
11415-2
11415-3
11415-4
11416-2
11416-3
11416-4
11417-2
11417-3
11417-4
Trouble
Cause
Influenced Control
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch First Gear becomes the uncertain value
Proportional Solenoid Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
First Gear Proportional Solenoid
Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
First Gear Proportional Solenoid
Valve
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch Second
becomes the uncertain value
Gear Proportional Solenoid
Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
Second
Gear
Proportional
Solenoid Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
Second
Gear
Proportional
Solenoid Valve
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch Third Gear becomes the uncertain value
Proportional Solenoid Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
Third
Gear
Proportional
Solenoid Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
Third
Gear
Proportional
Solenoid Valve
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch Fourth
becomes the uncertain value
Gear Proportional Solenoid
Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
Fourth
Gear
Proportional
Solenoid Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
Fourth
Gear
Proportional
Solenoid Valve
T5-5-83
TROUBLESHOOTING / Troubleshooting A
Fault Code
11418-2
11418-3
11418-4
11419-2
11419-3
11419-4
Trouble
Cause
Influenced Control
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch Forward
becomes the uncertain value
Proportional Solenoid Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
Forward Proportional Solenoid
Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
Forward Proportional Solenoid
Valve
Abnormal Feedback of
The feedback current to MC • All Transmission Control
Transmission Clutch Reverse
becomes the uncertain value
Proportional Solenoid Valve
Abnormal
Feedback
High The feedback current to MC • All Transmission Control
Current of Transmission Clutch exceeds the upper limit
Reverse Proportional Solenoid
Valve
Abnormal
Feedback
Low The feedback current to MC is • All Transmission Control
Current of Transmission Clutch 20 mA or less
Reverse Proportional Solenoid
Valve
T5-5-84
TROUBLESHOOTING / Troubleshooting A
NO
Switch proportional
solenoid valve with
normal one and retry.
Check if fault code
disappears.
YES
Faulty proportional
solenoid valve.
Faulty MC.
YES
Check for continuity in
harness between MC
and proportional
solenoid valve.
· Refer to tabel below.
Open circuit in harness.
NO
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-A
#A6
#A3
#A9 #A10
#A11
#A22
#A15
#A16 #A17 #A19 #A20
T183-05-04-008
#A30
Proportional Solenoid Valve Connector
1
2
List of connection relationship between each
proportional solenoid valve connector terminal and
connector MC-A terminal
First
Gear Second Gear Third
Gear Fourth
Gear Forward
Reverse
Proportional
Proportional
Proportional
Proportional
Proportional
Proportional
Solenoid Valve Solenoid Valve Solenoid Valve Solenoid Valve Solenoid Valve Solenoid Valve
Connector
Connector
Connector
Connector
Connector
Connector
Connector
MC-A
#1
#2
#1
#2
#1
#2
#1
#2
#1
#A10
#A6
#A22
#A16
#A20
#A3
#A11
#A17
#A30 #A19
T5-5-85
#2
#1
#2
#A9
#A15
TROUBLESHOOTING / Troubleshooting A
TRANSMISSION FAILURE
MC FAULT CODE 11600
Fault Code
11600-3
11600-4
Trouble
Abnormal Travel Speed Sensor
Cause
Influenced Control
The abnormal value below is All Transmission Control
detected with the clutch
connected.
• Travel speed sensor=0 min-1
• Middle shaft sensor>300
min-1
• Torque converter output
speed sensor>500 min-1
• Detected voltage under the
shorted circuit with key ON:
4.5 V or higher
Abnormal Low Voltage of Travel Detected voltage under the All Transmission Control
Speed Sensor
shorted circuit with key ON:
Less than 1.5 V
Connect terminals #1
and #2 of harness end
of connector in travel
speed sensor by using a
clip.
NO Disconnect connector
MC-C in MC.
Check for continuity
between terminals #C19
and #C7 of harness end
of connector MC-C.
Replace travel speed
sensor.
Turn key switch ON in 10
seconds
after key switch is
·
turned OFF. Retry.
Check if fault code
disappears.
Connect terminal #C19 of
harness end of connector
MC-C in MC to vehicle
frame.
Check for continuity
NO between terminal #2 of
harness end of connector
in travel speed sensor
and vehicle frame.
· Key switch: ON
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#C7
C23
C10
#C19
C31
Travel Speed Sensor Connector
#2
Open circuit in
YES harness between MC
and travel speed
sensor (terminal #1).
NO
Open circuit in
harness between MC
and travel speed
sensor (terminal #2).
Faulty travel speed
sensor.
YES
C1
Faulty MC.
YES
#1
T5-5-86
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11601
Fault Code
11601-3
Trouble
Cause
Influenced Control
Abnormal Torque Converter The abnormal value below is • Pump
Torque
Decrease
Output Speed Sensor
detected with the clutch
Control
connected.
• Torque converter output
speed sensor=0 min-1
• Middle shaft sensor>300
min-1
• Travel speed sensor>300
min-1
Connect terminals #1
and #2 of harness end
of connector in torque
converter output speed
sensor by using a clip.
YES
Disconnect connector
MC-C in MC.
Check for continuity
between terminals #C29
and #C18 of harness
end of connector MC-C.
Replace torque converter
output speed sensor.
Start engine in 10 seconds
after key switch is turned
OFF. Travel machine 20
m. Retry.
Check if fault code
disappears.
NO
· Key Switch: ON
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#C18
C23
C10
C31
#C29
Torque Converter Output Speed Sensor Connector
#2
Connect terminal #C29
of harness end of
connector MC-C in MC
to vehicle frame.
Check for continuity
between terminal #2 of
harness end of
connector in torque
converter output speed
sensor and vehicle
frame.
Open circuit in
harness between MC
YES
and torque converter
output speed sensor
(terminal #1).
NO
Open circuit in
harness between MC
and torque converter
output speed sensor
(terminal #2).
Faulty torque
converter output speed
sensor.
NO
C1
Faulty MC.
YES
#1
T5-5-87
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11602
Fault Code
11602-3
Trouble
Cause
Influenced Control
Abnormal Transmission Middle The abnormal value below is • All Transmission Control
Shaft Sensor
detected with the clutch
connected.
• Middle shaft sensor =0 min-1
• Travel speed sensor>500
min-1
• Torque converter output
speed sensor>500 min-1
Replace transmission
middle shaft sensor.
Start engine in 10 seconds
after key switch is turned
OFF. Travel machine 20 m.
Retry.
Check if fault code
disappears.
Connect terminals #1
and #2 of harness end of YES
connector in
transmission middle
shaft sensor by using a
YES clip.
Connect terminal #C17 of
Disconnect connector
harness end of connector
MC-C in MC.
MC-C in MC to vehicle
Check for continuity
frame.
between terminals #C17
Check for continuity
and #C6 of harness end
NO between terminal #2 of
of connector MC-C.
harness end of connector
in transmission middle
shaft sensor and vehicle
frame.
Faulty MC.
Open circuit in harness
YES between MC and
transmission middle
shaft sensor (terminal
#1).
NO
Open circuit in harness
between MC and
transmission middle
shaft sensor (terminal
#2).
· Key switch: ON
Faulty transmission
middle shaft sensor.
NO
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#C6
C1
C23
#C17
C10
C31
Transmission Middle Shaft Sensor Connector
#2
＃1
T5-5-88
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11904
Fault Code
11904-2
Abnormal
Lever
Trouble
Cause
Influenced Control
Forward/Reverse The forward/reverse signals All Transmission Control
are turned ON for 80 ms or
longer at the same time.
YES
NO
Disconnect connector of
forward/reverse lever.
Retry.
Check if fault code
disappears.
Disconnect connector
MC-B in MC.
Check for continuity
between terminal #2 or
#4 of connector in
forward/reverse lever
and vehicle frame
respectively.
Shorted circuit in
harness between
between connector of
forward/reverse lever
and connector MC-B
in MC.
Faulty MC.
NO
· Key switch: ON
Faulty
forward/reverse lever.
YES
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-C
#B2
#B4
T183-05-04-021
Forward/Reverse Lever Connector
#4
#2
4
1
8
5
T5-5-89
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11905
Fault Code
11905-2
Abnormal
Switch
Trouble
Cause
Influenced Control
Forward/Reverse The forward/reverse signals All Transmission Control
are turned ON for 80 ms or
longer at the same time.
YES
NO
Disconnect connector of
forward/reverse switch.
Retry.
Check if fault code
disappears.
Disconnect connector
MC-B in MC.
Check for continuity
between terminal #1 or
#3 of connector in
forward/reverse switch
and vehicle frame
respectively.
Shorted circuit in
harness between
between connector of
forward/reverse
switch and connector
MC-B in MC.
Faulty MC.
NO
· Key switch: ON
Faulty
forward/reverse
switch.
YES
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-B
#B3
#B1
T183-05-04-021
Forward/Reverse Switch Connector
#3
#1
T5-5-90
TROUBLESHOOTING / Troubleshooting A
CAN DATA RECEPTION FAILURE
MC FAULT CODES 11910, 11920
Fault Code
11910-2
11920-2
Trouble
Cause
Actual Engine Speed Receive Faulty Harness
Error
Faulty ECM1 or 2
Received from ECM1
Fuel Flow Rate Receive Error Faulty Harness
Received from ECM1
Faulty ECM1 or 2
Influenced Control
• Pump Torque Decrease Control
• Hydraulic Drive Fan Cooling
Control
• Engine
Speed
Control
GPS
Monitor Unit
Dr-ZX
ICF
ECM1
CAN Harness
MC
ECM2
T5-5-91
Decrease
TROUBLESHOOTING / Troubleshooting A
CAN HARNESS CHECK
MC FAULT CODES 11910, 11920
• Check the wiring connections first.
Disconnect all
connectors of MC, ICF,
ECM1 and monitor
unit.
YES Check for continuity
between ground circuit
(MC, ICF, ECM1,
monitor unit) and CAN
circuit.
Check for continuity in
YES CAN harness between
MC and ECM1.
· Key switch: OFF
· Refer to
“Discontinuity Check
between CAN Circuit
and Ground Circuit”
on T5-5-61 to 65.
· Key switch: OFF
· Refer to “Continuity
Check in CAN
Harness” on T5-5-59.
Retry by using Dr. ZX.
Check if fault code
11004-2 is displayed.
NO
YES
NO
Shorted circuit in CAN
harness between ground
circuit and CAN circuit.
Check for continuity
between power
To A
circuit MC, ICF,
ECM1, monitor unit
and CAN circuit.
· Key switch: OFF
· Refer to “Discontinuity
Check between CAN
Circuit and Power Circuit”
on T5-5-66 to 69.
Open circuit in CAN
harness between MC and
ECM1.
Normal.
NO
Shorted circuit in CAN
harness between power
circuit and CAN circuit.
YES
Shorted circuit in CAN
harness between key
signal circuit and CAN
circuit.
YES
A
Check for continuity
between key signal
circuit in MC, ICF,
NO ECM1, monitor unit
and CAN circuit.
· Key switch: OFF
· Refer to
“Discontinuity
Check between
CAN Circuit and
Key Signal Circuit”
on T5-5-70 to 72.
YES
NO
Check for continuity
between High side
and Low side in CAN
harness.
· Key switch: OFF
· Refer to
“Discontinuity Check
in CAN Harness” on
T5-5-73.
Shorted circuit in CAN
harness.
Connect all connectors
YES
except connector
MC-C in MC.
Disconnect
Check if resistance
connector in MC.
between terminals #C4
NO and #C15 of harness
Connect connector of
harness end.
end of connector
MC-C is within 60±10
NO Check if resistance
between terminals
Ω.
#D19 and #D21 of
· Key switch: OFF
connector ECM1-D in
ECM1 is within
120±10 Ω.
· Key switch: OFF
T5-5-92
To B
To C
TROUBLESHOOTING / Troubleshooting A
NO
Connect connector
in MC.
Check if fault code
11004-2 is
displayed.
B
Check the connections of
MC and connector.
Faulty MC.
YES
· Key switch: ON
Check the connections of
ECM1, 2 and connector.
NO
Connect connector
in MC.
YES Check if fault code
11004-2 is
displayed.
Faulty ECM1 or 2.
YES
· Key switch: ON
C
Connect connector in
ECM.
Disconnect
connector ICF-C in
ICF.
Check if resistance
NO between terminals
#C5 and #C11 of
harness end of
connector is within
60±10 Ω.
· Key switch: OFF
Connect connector
in ICF.
YES Check if fault code
11004-2 is
displayed.
NO
· Key switch: ON
YES
NO
Connect connector in
ICF.
Disconnect
connector monitor-2B
in monitor unit.
Check if resistance
between terminals
#B33 and #B34 of
harness end of
connector is within
120±10 Ω.
Check the connection of
ICF and connector.
Faulty ICF.
Connect connector
in monitor unit.
Check if fault code
11004-2 is
displayed.
YES
· Key switch: ON
NO
Check the connections of
monitor unit and
connector.
Faulty monitor unit.
YES
Faulty in any controller in
MC, ICF, ECM1, 2 or
monitor unit.
NO
· Key switch: OFF
Connector
ECM1
Connector ECM1-D
(Harness end)
MC
Connector MC-C
(Harness end)
#C4
C1
C23
ICF
Connector ICF
(Harness end)
#D19
#C15
C10
#D21
C31
Monitor Unit
Connector Monitor-2B
(Harness end)
#C5
#C11
T1V1-05-04-002
T4GB-05-05-002
#B34 #B33
T5-5-93
TROUBLESHOOTING / Troubleshooting A
(Blank)
T5-5-94
TROUBLESHOOTING / Troubleshooting A
MC FAULT CODE 11914
Fault Code
11914-2
Trouble
Cause
Radiator
Coolant Faulty Harness
Temperature Receive Error Faulty Monitor Unit
Received from Monitor Unit
Influenced Control
• Hydraulic Drive Fan Cooling Control
GPS
Monitor Unit
Dr-ZX
ICF
ECM1
CAN Harness
MC
ECM2
T5-5-95
TROUBLESHOOTING / Troubleshooting A
CAN HARNESS CHECK
FAULT CODE 11914
• Check the wiring connections first.
Disconnect all
connectors of MC, ICF,
ECM1 and monitor
YES unit.
Check for continuity
between ground circuit
MC, ICF, ECM1,
monitor unit and CAN
circuit.
Check for continuity in
YES CAN harness between
MC and monitor unit.
NO
· Key switch: OFF
· Refer to
“Discontinuity Check
between CAN Circuit
and Ground Circuit”
on T5-5-61 to 65.
· Key switch: OFF
· Refer to “Continuity
Check in CAN
Harness” on T5-5-60.
Retry by using Dr. ZX.
Check if fault code
11004-2 is displayed.
YES Open circuit in CAN
harness between ground
circuit and CAN circuit.
Check for continuity
between power
circuit MC, ICF,
To A
ECM1, monitor unit
and CAN circuit.
· Key switch: OFF
· Refer to
“Discontinuity Check
between CAN Circuit
and Power Circuit” on
T5-5-66 to 69.
Open circuit in CAN
harness between MC and
monitor unit.
NO
Normal.
NO
Shorted circuit in CAN
harness between power
circuit and CAN circuit.
YES
Shorted circuit in CAN
harness between key
signal circuit and CAN
circuit.
YES
A
Check for continuity
between key signal
circuit in MC, ICF,
NO ECM1, monitor unit
and CAN circuit.
· Key switch: OFF
· Refer to
“Discontinuity
Check between
CAN Circuit and
Key Signal Circuit”
on T5-5-70 to 72.
YES
NO
Check for continuity
between High side
and Low side in CAN
harness.
· Key switch: OFF
· Refer to
“Discontinuity Check
in CAN Harness” on
T5-5-73.
NO
Shorted circuit in CAN
harness.
Connect all
connectors except
connector MC-C in
MC.
Check if resistance
between terminals
#C4 and #C15 of
harness end of
connector MC-C is
within 60±10 Ω.
· Key switch: OFF
YES
NO
To B
Connect connector in
MC.
Disconnect
connector monitor-2B
in monitor unit.
Check if resistance
between terminals
#B33 and #B34 of
harness end of
connector is within
120±10 Ω.
· Key switch: OFF
T5-5-96
To C
TROUBLESHOOTING / Troubleshooting A
NO
Check the connections of
MC and connector.
Connect connector
in MC. Check if fault
code 11004-2 is
displayed.
B
Faulty MC.
· Key witch: ON
YES
Connect connector
in monitor unit.
YES Check if fault code
11004-2 is
displayed.
NO
Check the connections of
monitor unit and
connector.
Faulty monitor unit.
YES
· Key witch: ON
C
Connect connector in
monitor unit.
Disconnect
connector ECM1-D in
ECM1.
NO Check if resistance
between terminals
#D19 and #D21 of
harness end of
connector is within
60±10 Ω.
Connect connector
in ECM1.
YES Check if fault code
11004-2 is
displayed.
NO
· Key witch: ON
YES
NO
· Key witch: OFF
Connect connector in
ECM1.
Disconnect
connector ICF-C in
ICF.
Check if resistance
between terminals
#C5 and #C11 of
harness end of
connector is within
60±10 Ω.
Check the connections of
ICF and connector.
Faulty ICF.
YES
Connect connector
in ICF.
Check if fault code
11004-2 is
displayed.
· Key witch: ON
NO Check the connections of
ICF and connector.
Faulty ICF.
YES
Faulty In any controller in
MC, ICF, ECM1 or
monitor unit.
NO
· Key witch: OFF
Connector
MC
Connector MC-C
(Harness end)
#C4
Monitor Unit
Connector Monitor-2B
(Harness end)
#C15
C1
C23
C10
C31
T4GB-05-05-002
ICF
Connector ICF-C
(Harness end)
ECM1
Connector ECM1-D
(Harness end)
#C5
#D19
#C11
T1V1-05-04-002
#D21
T5-5-97
#B34 #B33
TROUBLESHOOTING / Troubleshooting A
(Blank)
T5-5-98
TROUBLESHOOTING / Troubleshooting A
OTHER FAILURES
MC FAULT CODE 11901
Fault Code
Trouble
Cause
11901-3 Hydraulic
Oil
Temperature Voltage: 4.52 V or higher
Sensor High Voltage
11901-4
Hydraulic
Oil
Temperature Voltage: Less than 0.23 V
Sensor Low Voltage
Disconnect connector of
hydraulic oil temperature
sensor.
Check if resistance at
sensor end connector is
specification.
· Specification: Refer to
the table below.
Connect terminals #1
and #2 of harness end
of connector in
hydraulic oil
temperature sensor by
YES using a clip.
Disconnect connector
MC-D from MC.
Check for continuity
between terminals #D8
and #D6 of harness
end of connector
MC-D.
Influenced Control
• Auto Warning-Up Control
• Hydraulic Drive Fan Cooling
Control
• Auto Warning-Up Control
• Hydraulic Drive Fan Cooling
Control
Faulty MC.
YES
NO
Connect terminal #D6
of harness end of
connector MC-D in
MC to vehicle frame.
Check for continuity
between terminal #2
of harness end of
connector in hydraulic
oil temperature
sensor and vehicle
frame.
NO
Open circuit in harness
between MC and
hydraulic oil temperature
sensor (terminal #2).
Faulty hydraulic oil
temperature sensor.
NO
Specification of Hydraulic Oil Temperature Sensor
Hydraulic Oil Temperature
Resistance
(°C, °F)
(kΩ)
-20, -4
16.2±1.6
0, 32
(5.88)
20, 68
2.45±0.24
40, 104
(1.14)
60, 140
(0.534)
80, 176
0.322
NOTE: If fault code 11901-4 is not displayed and
hydraulic oil temperature “-30°C” is
displayed on the monitor by using Dr. ZX,
the circuit in hydraulic oil temperature
sensor may be opened.
Connector (Harness end of connector viewed from the
open end side)
MC
Connector MC-D
Hydraulic Oil Temperature
Sensor Connector
#D8
1
#D6
Open circuit in harness
YES between MC and
hydraulic oil temperature
sensor (terminal #1).
T183-05-04-009
T5-5-99
2
TROUBLESHOOTING / Troubleshooting A
PROPORTIONAL
TROUBLE CHECK
SOLENOID
VALVE
When the harness in proportional solenoid valve is
faulty, the fault code may be not detected. If the trouble
is related to the proportional solenoid valve,
disconnect the connectors in MC and proportional
solenoid valve. Then check for continuity.
Circuit Condition in Trouble
A
B
D
C
MC
Proportional
Solenoid Valve
A
B
D
C
T1V1-05-06-008
○: Fault code can be detected.
△: Fault code can be detected according to trouble.
×: Fault code cannot be detected.
Trouble
Fault Code
Open circuit in A-B
△
Damaged Parts in MC
None
T1V1-05-06-006
A
B
D
C
None
• Open circuit in A-B
• Harness in side B is shorted to
the ground.
○
T1V1-05-06-007
A
B
D
C
FET
• Open circuit in A-B
• Harness in side A is shorted to
△
the ground.
T1V1-05-06-009
A
B
D
C
Shorted circuit in A-B
FET
○
T1V1-05-06-010
A
B
D
C
Open circuit in C-D
None
△
T1V1-05-06-011
A
B
D
C
None
• Open circuit in C-D
• Harness in side C is shorted to
the ground.
△
T1V1-05-06-012
A
B
D
C
None
• Open circuit in C-D
• Harness in side D is shorted to
○
the ground.
T1V1-05-06-013
A
B
D
C
Shorted circuit in C-D
None
△
T1V1-05-06-014
T5-5-100
TROUBLESHOOTING / Troubleshooting A
Circuit Condition in Trouble
A
B
D
C
Trouble
Fault Code
Shorted circuit in harness
×
Damaged Parts in MC
Resistance
between A-B and C-D
T1V1-05-06-015
A
B
D
C
• Open circuit in A- B
• Harness in side A is shorted to
None
△
the power source.
T1V1-05-06-016
A
B
D
C
• Open circuit in A- B
• Harness in side B is shorted to
the power source.
None
○
T1V1-05-06-017
A
B
D
C
Harness in A-B is shorted to the
power source.
None
○
T1V1-05-06-018
A
B
D
C
• Open circuit in C-D
Resistance
• Harness in side D is shorted to
the power source.
○
T1V1-05-06-019
A
B
D
C
• Open circuit in C-D
None
• Harness in side C is shorted to
△
the power source.
T1V1-05-06-020
A
B
Harness in C-D is shorted to the
power source.
D
Resistance
○
C
T1V1-05-06-021
T5-5-101
TROUBLESHOOTING / Troubleshooting A
(Blank)
T5-5-102
TROUBLESHOOTING / Troubleshooting A
Each Connector Terminal Role in ECM1
Connector ECM1-A (15 Pins)
Terminal
Signal
Role
Connected To
No.
Type
When the transmission neutral siganl is received, the Terminal #1 in neutral relay
1
Input
circuit is grounded and the engine is impossible to
start.
Intake-air heater power supply
Terminal #2 in intake-air heater
9
Output
relay
Communication signal output of overheating
Terminal #7 of connector 1A in
11
Output
monitor unit
Input/
CAN High line
Terminal #1 of pin 16 connector in
13
Output
ECM2
CAN ground
Terminal #3 of pin 16 connector in
14
ECM2
Input/
CAN Low line
Terminal #2 of pin 16 connector in
15
Output
ECM2
Pin Connector ECM1-B (18 Pins)
Terminal
Signal
Role
No.
Type
Remote throttle power supply
17
Output
18
Input
Signal receive of remote throttle feedback
Connected To
Wiring terminal #189 in accelerator
pedal
Wiring terminal #544 in accelerator
pedal
Connector ECM1-C (12 Pins)
Terminal
Signal
Role
Connected To
No.
Type
Engine start terminal 50
Terminal ST in key switch
When the siganl is received, the circuit is grounded,
1
Input
battery powetr is supplied to the starter and the
engine can start.
Input/
Connecting line for diagnosis tool (K-Line) by Terminal #14 of connector for
2
Output
DaimlerChrysler
MiniDiag2
Communication signal output of engine oil pressure Terminal #7 of connector 1A in
3
Output
decrease
monitor unit
Signal sending of low coolant temperature for coolant Terminal #9 of connector 1A in
4
Output
gauge
monitor unit
Signal input of intake-air heater operation
Terminal #5 in intake-air heater
10
Input
relay
T5-5-103
TROUBLESHOOTING / Troubleshooting A
Connector ECM1-D (21 Pins)
Terminal
Signal
Role
Connected To
No.
Type
1
Input
Battery power input
Terminal (+) in battery
2
Input
Ignition switch
Terminal M (ON) in key switch
3
Battery grounding
Terminal (-) in battery
If engine oil level is low, the check/maintenance alarm Terminal #22 of connector 2B in
5
Output
signal is sent.
monitor unit
If abnormal value is received from the sensors except Terminal #21 of connector 2B in
6
Output
the engine oil level sensor, the stop signal is sent.
monitor unit
While current flows through the intake-air heater, the Terminal #1 of connector 2A in
7
Output
signal is sent.
monitor unit
14
Accelerator pedal grounding
Machine grounding
Input/
CAN High line between each controller
Terminal of CAN High line in each
19
Output
controller
20
Shield grounding in CAN cable
Shield wire grounding
Input/
CAN Low line between each controller
Terminal of CAN Low line in each
21
Output
controller
NOTE: the terminal without No. is not used.
T5-5-104
TROUBLESHOOTING / Troubleshooting A
Terminal No. of connector end in Connector ECM1 (Wiring terminal No. of connector end in parentheses)
1
（116）
13
（A3）
14
11
（659）（249）
15
（B3）
17
（461）
9
（60）
18
（459）
Connector
ECM1-B
Connector
ECM1-A
10
（658）
4
1
（667）（665）
19
（A2）
2
（471）
20
（872）
3
（244）
21
（B2）
Connector
ECM1-C
7
（233）
14
（462）
1
（7）
2
5
（433） （56）
6
3
（243） （666）
Connector
ECM1-D
T5-5-105
TROUBLESHOOTING / Troubleshooting A
EACH CONNECTOR TERMINAL ROLE IN ECM2
55 Pin Connector of ECM2
Terminal Signal
Role
No.
Type
Signal receive of cam shaft sensor detection
1
Input
2
3
Input
Input
4
Input
6
Output
7
Output
9
Output
10
Input
15
Input
16
Output
18
Output
19
Output
20
Output
23
Input
25
Input
29
-
30
Output
32
-
33
-
34
Output
35
Input
Connected To
Terminal #1 of connector in cam shaft
sensor
Signal receive of crank shaft sensor detection
Terminal #2 of connector in crank shaft
sensor
Signal receive of coolant temperature sensor Terminal #2 of connector in coolant
detection
temperature sensor
Signal receive of fuel temperature sensor Terminal #2 of connector in fuel
detection
temperature sensor
Power supply of oil pressure sensor
Terminal #2 of connector in oil pressure
sensor
Power supply of intake-air pressure sensor
Terminal #3 of connector in intake-air
combination sensor
Power supply of unit pump for 2, 4, 6 cylinders Round terminal of connector in unit pump
for 2, 4, 6 cylinders
Signal receive of oil pressure sensor detection
Terminal #1 of connector in oil
combination sensor
Signal receive of engine oil temperature sensor Terminal #3 of connector in oil
detection
combination sensor
Power supply of unit pump for 1, 3, 5 cylinders Round terminal of connector in unit pump
for 1, 3, 5 cylinders
Signal output of stater starting
Terminal S in starter motor
Signal receive of cam shaft sensor detection
Terminal #2 of connector in cam shaft
sensor
Signal receive of crank shaft sensor detection
Terminal #1 of connector in crank shaft
sensor
Signal receive of intake-air pressure sensor Terminal #1 of connector in intake-air
detection
combination sensor
Signal receive of engine start in service engine Terminal #1 of connector in service
switch
engine switch
Intake-air pressure sensor grounding
Terminal #4 of connector in intake-air
combination sensor
Power supply of service engine switch
Terminal #2 of connector in service
engine switch
Oil combination sensor grounding
Terminal #4 of connector in oil
combination sensor
Engine oil level switch grounding
Terminal #1 of connector in engine oil
level switch
Power supply of coolant temperature sensor
Terminal #1 of connector in coolant
temperature sensor
Signal receive of engine stop in service engine Terminal #3 of connector in service
switch
engine switch
NOTE: the terminal without No. is not used.
T5-5-106
TROUBLESHOOTING / Troubleshooting A
Terminal
No.
Signal
Type
36
Output
38
Input
39
Output
44
Input
45
Input
47
Input
48
Input
49
Input
53
Input
54
Input
Role
Connected To
Power supply of fuel temperature sensor
Terminal #1 of connector in fuel
temperature sensor
Round terminal of connector in unit pump
Unit pump control in cylinder #6
for cylinder #6
Power supply of engine oil temperature sensor Terminal #1 of connector in engine oil
temperature sensor
Round terminal of connector in unit pump
Unit pump control in cylinder #4
for cylinder #4
Round terminal of connector in unit pump
Unit pump control in cylinder #2
for cylinder #2
Round terminal of connector in unit pump
Unit pump control in cylinder #5
for cylinder #5
Signal receive of intake-air temperature sensor Terminal #2 of connector in intake-air
combination sensor
Signal receive of engine oil level switch Terminal #1 of connector in engine oil
detection
level switch
Round terminal of connector in unit pump
Unit pump control in cylinder #3
for cylinder #3
Round terminal of connector in unit pump
Unit pump control in cylinder #1
for cylinder #1
NOTE: the terminal without No. is not used.
T5-5-107
TROUBLESHOOTING / Troubleshooting A
16 Pin Connector of ECM2
Terminal Signal
Role
No.
Type
Input/
CAN High line between ECM1
1
Output
Input/
CAN Low line between ECM1
2
Output
3
Grounding between ECM1
4
Grounding between ECM1
5
Battery voltage
6
Battery voltage
8
Input
Treminal 50 (starting)
9
Battery grounding
11
Battery grounding
12
Output Starter
Input/
Diagnosing
13
Output
15
Input
Terminal 15
Connected To
Terminal #13 of connector A in ECM1
Terminal #15 of connector A in ECM1
Terminal #14 of connector A in ECM1
Terminal #14 of connector A in ECM1
Terminal (+) in battery
Terminal (+) in battery
Terminal ST in key switch
Terminal (-) in battery
Terminal (-) in battery
Terminal S in starter motor
Terminal #5 of connector in MiniDiag2
Terminal M (ON) in key switch
NOTE: the terminal without No. is not used.
Terminal No. of connector end in Connector ECM2 (Wiring terminal No. of connector end in parentheses)
1
2
3
４
5
6
8
（A3） （B3） （659） （660） （661）（662）
（754）
9
12
13
15
11
（499）
（464）
（500） （228） （470）
16 Pin Connector of
ECM2
1
19
2
3
6
20
38
23
39
41
7
9
10
25
43
12
29
44
45
47
30
48
55 Pin Connector of
ECM2
T5-5-108
15
32
49
33
16
34
18
35
53
54
TROUBLESHOOTING / Troubleshooting A
ICF, SATELLITE TERMINAL FAULT CODES 14000 to 14003
Fault Code
Trouble
14000-2 Abnormal CAN Communication
14001-2
14002-2
14003-2
ICF: Flash Memory
Read / Write Error
ICF: External RAM
Read Error
ICF: EEPROM
Sum Check Error
Remedy
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, check the following
item.
• Check the CAN communication line (harness).
Execute retry B in self-diagnosing and execute the following
item.
• Execute “Information C/U: Initialize”.
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, check the following
item.
• Execute “Control Data: Initialize”.
• Execute “Enter Model and Serial No.”.
Then, execute self-diagnosing and execute retry B.
T5-5-109
TROUBLESHOOTING / Troubleshooting A
Information C/U: Initialize
After starting Dr. ZX, push Select
Controller.
Push ICF Controller.
Select Function
Select failure-diagnosis
controller
+
Self-Diagnostic Result
+
Select Controller
Push OK.
+
Main Controller
+
Engine Controller
・ ICF
Controller Ver.: XXYY
・ Satellite Terminal
Controller Ver.: XXYY
+
Monitor Controller
Is it correct?
+
ICF Controller
ESC
ESC
OK
To the
lower
ESC
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Start.
Push Information
Setup.
Push Information C/U: Initialize.
C/U:
Various
Select Item
Password
Information C/U: Various
Setup
+
Dr. ZX SerVice Soft
(C)Hitachi Construction
Machinery Co., ltd
Select Item
+
Data Download
+
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Save Data Check
+
+
Enter Date and Time
Control Data: Initialize
Op. Manual
Start
Back
ESC
Title Screen
Main Menu Screen
Push Init and the controller
operating data is initialized.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
Information C/U: Initialize
Init
i
Initialization has been
completed.
Initialization has been
completed.
ESC
ESC
Information C/U: Various Setup
Screen
Push ESC and return to Main
Menu Screen.
Select Item
Is operation data erased?
Init
ESC
OK
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: initialize
ESC
Information C/U: Initialize Screen
Information C/U: Various Setup
Screen
T5-5-110
To the
lower
TROUBLESHOOTING / Troubleshooting A
Control Data: Initialize
After starting Dr. ZX, push Select
Controller.
Push ICF Controller.
Select Function
Select failure-diagnosis
controller
+
Self-Diagnostic Result
+
Select Controller
Push OK.
+
Main Controller
+
Engine Controller
・ ICF
Controller Ver.: XXYY
・ Satellite Terminal
Controller Ver.: XXYY
+
Monitor Controller
Is it correct?
+
ICF Controller
ESC
ESC
OK
To the
lower
ESC
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Start.
Push Information
Setup.
Push Control Data: Initialize.
C/U:
Various
Select Item
Password
Information C/U: Various
Setup
+
Dr. ZX SerVice Soft
(C)Hitachi Construction
Machinery Co., ltd
Select Item
+
Data Download
+
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Save Data Check
+
+
Enter Date and Time
Control Data: Initialize
Op. Manual
Start
Back
ESC
Title Screen
Main Menu Screen
Push Init and the controller control
data is initialized.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Push OK and return to Information
C/U: Various Setup Screen.
ESC
Information C/U: Various Setup
Screen
Push ESC and return to Main
Menu Screen.
Select Item
Control Data: Initialize
+ Information C/U: Initialize
Is control data initialized?
Init
i
Initialization has been
completed.
Initialization has been
completed.
ESC
Init
ESC
+ Enter Model and Serial
No.
+ Enter Date and Time
+ Control Data: Initialize
OK
ESC
Control Data: Initialize Screen
Information C/U: Various Setup
Screen
T5-5-111
To the
lower
TROUBLESHOOTING / Troubleshooting A
Enter Model and Serial No.
After starting Dr. ZX, push Select
Controller.
Push ICF Controller.
Select Function
Select failure-diagnosis
controller
+
+
Self-Diagnostic Result
Select Controller
Push OK.
+
Main Controller
+
Engine Controller
・ ICF
Controller Ver.: XXYY
・ Satellite Terminal
Controller Ver.: XXYY
+
Monitor Controller
Is it correct?
+
ICF Controller
ESC
ESC
OK
To the
lower
ESC
Function Selection Screen
Controller Selection Screen
ICF Controller Screen
Push Start.
Push Information
Setup.
Push Enter Model and Serial No.
C/U:
Various
Select Item
Password
+
Dr. ZX SerVice Soft
(C)Hitachi Construction
Machinery Co., ltd
+
+
Select Item
Information C/U: Various
Setup
Data Download
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Save Data Check
+
+
Enter Date and Time
Control Data: Initialize
Op. Manual
Start
Back
ESC
Main Menu Screen
Title Screen
Enter Model and Serial No.
Push ESC and return to Main
Menu Screen.
Enter Model and Serial No.
04HA
Select Item
Model |
Exec
Serial No. 000001
Exec
Information C/U: Various Setup
Screen
After inputting model and serial No.,
push OK and return to Enter Model
and Serial No. Screen.
Push ESC and return to Information
C/U: Various Setup Screen.
Push Exec, and model and serial
No. can be input.
Push
ESC
and
return
to
Information C/U: Various Setup
Screen.
Model
ESC
ESC
ESC
Ex. Mach.No.(HCM4HA00P00
0001) Model(04HA)
Serial No.
Ex. Mach.No.(HCM4HA00P00
0001) Serial No.(000001)
OK
ESC
Enter Model and Serial No.
ESC
OK
+
Information C/U: Initialize
+
Enter Model and Serial
No.
+
Enter Date and Time
+
Control Data: Initialize
ESC
Information C/U: Various Setup
Screen
T5-5-112
To the
lower
TROUBLESHOOTING / Troubleshooting A
ICF, SATELLITE TERMINAL FAULT CODES 14006, 14008, 14100 to 14106
Fault Code
Trouble
Remedy
14006-2 ICF:
Satellite
Communication Execute retry B in self-diagnosing.
Terminal Communication Error
If this error code is displayed after re-try, check the following
item.
• Check the communication line.
• Check the power source line of satellite terminal.
• Check the fuse.
14008-2
ICF: Abnormal Internal RAM
Then, execute self-diagnosing and execute retry B.
Execute retry B in self-diagnosing.
If this error code is displayed after re-try, replace the
controller.
14100-2
Satellite Communication Terminal:
Abnormal EEPROM
14101-2 Satellite Communication Terminal:
Abnormal IB/OB Queue
14102-2 Satellite Communication Terminal: Check the communication aerial of satellite terminal. (Refer
to T5-5-114.)
Abnormal Local Loup Back
14103-2 Satellite Communication Terminal:
The satellite is not found.
14104-2 Satellite Communication Terminal: Execute retry B in self-diagnosing.
Fail 1 of Remote Loup Back
If this error code is displayed after re-try, replace the
14105-2 Satellite Communication Terminal: controller.
Fail 2 of Remote Loup Back
14106-2 Satellite Communication Terminal:
Sending and receiving data are
mismatched.
Fault Code 14006-2
• Check the communication line
Connector (Harness end of connector viewed from the
1. Check for continuity between terminal #A8 of
open end side)
harness end of connector ICF-A in ICF and
terminal #A10 of harness end of connector A in
satellite terminal.
ICF
2. Check for continuity between terminal #A9 of
Connector ICF-A
harness end of connector ICF-A in ICF and
#A8
terminal #A20 of harness end of connector A in
#A9
satellite terminal.
3. Check for continuity between terminal #A31 of
#A31
harness end of connector ICF-A in ICF and
Satellite Terminal
terminal #A2 of harness end of connector B in
Connector A
satellite terminal.
#A2
• Check the power source line of satellite terminal
#A10
10 9 8 7 6 5 4 3 2 1
#A1
1. Check the battery power
20 19 18 17 16 15 14 13 12 11
Check if voltage between terminal #A2 of harness
#A11
#A20
end of connector A in satellite terminal and vehicle
#A12
frame is 24 V.
Satellite Terminal
Connector
B
2. Check the main power
#B2
With the key switch ON, check if voltage between
8 7 6 5 4 3 2 1
terminal #A1 of harness end of connector A in
16 15 14 13 12 11 10 9
satellite terminal and vehicle frame is 24 V.
3. Check the ground circuit
Check for continuity between terminals #A11 and
#A12 of harness end of connector A in satellite
terminal.
T5-5-113
TROUBLESHOOTING / Troubleshooting A
Fault Codes 14102-2, 14103-2
GPS Aerial
Communication
Aerial
T4GB-05-07-002
Satellite Terminal
Communication
Aerial
GPS Aerial
T1V1-05-06-004
T5-5-114
TROUBLESHOOTING / Troubleshooting A
MONITOR UNIT FAULT CODES 13306, 13308
Fault Code
Trouble
13306-2
Abnormal EEPROM
13308-2
Abnormal CAN Communication
Remedy
If this error code is displayed after re-try, replace the monitor
unit.
Refer to “Check CAN Harness” (T5-5-58).
T5-5-115
TROUBLESHOOTING / Troubleshooting A
MONITOR UNIT FAULT CODE 13312
Fault Code
13312-2
Trouble
Remedy
Abnormal
Transmission
Temperature Sensor
YES
Check if sensor resistance
is specification.
Oil Execute re-try.
Check the transmission oil temperature sensor and harness.
With sensor connector
disconnected, check for
continuity between terminal #5
of harness end of connector
2-A in monitor unit and vehicle
frame.
Shorted circuit in harness
between monitor unit and
sensor.
Faulty monitor unit.
NO
Faulty transmission oil
temperature sensor.
NO
Transmission Oil Temperature Sensor
Coolant Temperature
Resistance
(°C, °F)
(kΩ)
25, 77
7.6±0.76
40, 104
4.0±0.35
50, 122
2.7±0.22
80, 176
0.92±0.07
95, 203
0.56±0.04
105, 221
0.42±0.03
120, 248
0.28±0.01
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
YES
#5
T183-05-04-013
T5-5-116
TROUBLESHOOTING / Troubleshooting A
MONITOR UNIT FAULT CODE 13314
Fault Code
13314-3
13314-4
Trouble
Remedy
Service Brake Pressure Sensor High Execute re-try.
Voltage
Check the service brake pressure sensor and harness.
Service Brake Pressure Sensor Low Execute re-try.
Voltage
Check the service brake pressure sensor and harness.
Disconnect connector
of pressure sensor.
Check if voltage
NO between termnals #1
and #3 of harness end
connector is 5±0.5 V.
· Key switch: ON
Check if haness
between terminal #6 of
hanress end of
YES connector 2-A in
monitor unit and
terminal #2 in pressure
sensor is open or
shorted.
Check if voltage
between termnal #1
of harness end
connector in pressure
NO
sensor and vehicle
frame is 5±0.5 V.
Replace pressure
sensors and retry.
Check if fault code
disappears.
· Key switch: ON
YES
Faulty harness
between monitor unit
and pressure sensor.
Faulty monitor unit.
NO
Open circuit in
YES harness between MC
and pressure sensor
(terminal #3).
Open circuit in
harness between MC
NO and pressure sensor
(terminal #1).
Faulty service brake
pressure sensor.
YES
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
Service Brake Pressure Sensor Connector
#6
1
T183-05-04-013
T5-5-117
2
3
TROUBLESHOOTING / Troubleshooting A
MONITOR UNIT FAULT CODE 13334
Fault Code
13334-2
Trouble
Radiator
Coolant
Receive Error
YES
Check if sensor resistance
is specification.
Remedy
Temperature Execute re-try.
Check the Coolant temperature sensor and harness.
With sensor connector
disconnected, check for
continuity between terminal #9
of harness end of connector
2-A in monitor unit and vehicle
frame.
Shorted circuit in harness
between monitor unit and
sensor.
Faulty monitor unit.
NO
Faulty coolant temperature
sensor.
NO
Coolnt Temperature Sensor
Coolant Temperature
(°C, °F)
25, 77
40, 104
50, 122
80, 176
95, 203
105, 221
120, 248
YES
Resistance
(kΩ)
447
287
200
69
44±2.5
33±2.5
23
Connector (Harness end of connector viewed from the
open end side)
Monitor
Unit
Monitor Unit
Connector
2-A
Connector 2-A
#9
T183-05-04-013
T5-5-118
TROUBLESHOOTING / Troubleshooting B
TROUBLESHOOTING B PROCEDURE
Apply troubleshooting B procedure when no fault code
is displayed on the service mode (built-in diagnosing
system) in monitor and Dr.ZX although the machine
operation is abnormal.
On the front section pages of this group are the tables
indicating the relationship between machine trouble
symptoms and related parts which may cause such
trouble if failed.
Start the troubleshooting with more probable causes
selected by referring to these tables.
• How to Read the Troubleshoting Flow Charts
YES(OK)
・
(2)
• After checking or measuring item (1), select either YES (OK) or
NO (NOT OK) and proceed to item (2) or (3), as appropriate.
(1)
NO(NOT OK)
(3)
• Special instructions or reference item are indicated in the spaces under the box.
・
· Key switch: ON
Incorrect measuring or checking methods will render troubleshooting impossible,
and may damage components as well.
・
• Use the service mode in monitor and the diagnosing system/controller diagnosing
・
• Causes are stated in a thick-line box. Scanning through thick-line boxes, possible
system in Dr.ZX.
causes can be seen without going through the flow chart.
T5-6-1
TROUBLESHOOTING / Troubleshooting B
RELATIONSHIP
BETWEEN
MACHINE
TROUBLE SYMPTOMS AND RELATED
PARTS
This table indicates the relationship between machine
trouble symptoms and the potential problem parts,
which may cause trouble if failed, and the evaluation
methods of these components.
Function
Parts
Symptoms in control
system when trouble occurs.
Symptoms in machine
operation when trouble
occurs.
Forward/Reverse Lever
• Sends the command signal
• Keeps MC in neutral when
• Although the forward/reverse
Shift Switch
• Sends the command signal
• Particular speed gear only
• When the travel mode switch
Parking Brake Switch
• Releases/applies the parking
• The parking brake cannot be
• Although the parking brake
on Forward/Reverse to MC.
• Sends the signal on forward/reverse to the neutral
relay.
on speed gear to MC.
brake.
traveling.
can be operated according to
condition of the shorted or
open circuit.
released or applied.
lever is operated, the machine does not travel.
• Although the forward/reverse
lever is in Reverse, the backlight and back buzzer are not
operated.
is manually operated, the
machine can travel at particular speed gear only.
• When the travel mode switch
is automatically operated,
speed can be shifted to particular speed gear only.
switch is OFF, the machine
cannot operate in the forward
or reverse direction.
• Although the parking brake
switch is ON on the slope,
the machine moves.
Mode
Selector • Sends the command signal
• MC makes only the travel
• When the automatic gear
Work Mode
Switch
Selector • Sends the command siganl
• MC keeps the work mode
• Although mode L has been
• MC makes the clutch cut-off
• Although mode S,N or D in
Travel
Switch
on travel mode to MC.
on work mode to MC.
Clutch Cut-Off Position • Sends the command siganl
on clutch cut-off to MC.
Switch
mode in manual gear shifting
operable.
selector switch in Normal
mode.
mode disabled.
shifting is selected, the machine can travel in the travel
mode in manual gear shifting
only.
used, fuel consumption suddenly increases after certain
week or month.
• Machine operation may be
normal according to the
switch by which engine output is controlled to low at low
speed gear.
the clutch cut-off mode
switch is selected and the
brake pedal is depressed,
the clutch cut-off is not operated.
Down-Shift Switch
Down-Shift/Up-Shift
Switch
• Sends the command signal
• MC makes
• Although the
Hold Switch
• Sends the command signal
• MC makes hold switch
• Although the auto spped gear
on down-shift/up-shift switch
to MC. (The circuit in
down-shift switch is
connected to that at
down-shift side in
down-shift/up-shift switch.)
on hold switch to MC.
down-shift/up-shift switch
control disabled.
control disabled.
T5-6-2
down-shift/up-shift switch is
pushed, down-shift/up-shift is
not operated.
• Although the down-shift
switch is pushed, down-shift
is not operated.
shifting is selected and the
hold switch is pushed, travel
speed gear is not fixed.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC: 11904
MC Monitor Item: FNR
switch, Selected speed gear,
Actual
speed
gear,
Backward alarm, Neutral
signal
NOTE
T2-1, T2-4
-
T2-1, T2-4
MC Monitor Item: Selected
speed gear, Actual speed
gear, Speed gear
-
-
• The parking brake is the spool regulated
-
-
MC
Monitor
Item:
Auto/manual selection, auto
speed gear shifting mode
T2-1
-
T2-1
MC Monitor Item: Engine
torque control, Pump torque
control
-
-
T2-1
MC Monitor Item: Clutch
cut-off switch, Clutch cut-off
mode
-
DSS
• Altough other levers and switches
T2-1
MC Monitor Item: Speed
gear hold switch, Hold mode
• Altough other levers and switches
T2-1
MC Monitor Item:
switch, USS switch
-
-
T2-1, T2-3, T2-4
pump control circtuit (The parking brake
is released with the parking brake switch
OFF).
• If the parking brake pressure sensor is
faulty, the parking brake indicator does
not light with the parking brake switch
ON.
-
-
Descriptions of Control
(Operational Principle
Section in T/M)
corresponding to travel are operated
and the down-shift/up-shift switch
control is disabled, this contition is
normal.
corresponding to travel are operated
and the hold switch control is disabled,
this contition is normal.
T5-6-3
TROUBLESHOOTING / Troubleshooting B
Parts
Function
Symptoms in control
system when trouble occurs.
Symptoms in machine
operation when trouble
occurs.
• Sends the command signal
• MC makes forward/reverse
• The machine cannot travel
Forward/Reverse Selec- • Sends the command signal
that the forward/reverse
tor Switch
switch is enabled during the
• The machine cannot travel
• The machine cannot travel
Forward/Reverse Switch
on forward/reverse to MC.
• When the machine travels
forward, the signal on
forward is sent to the neutral
relay in forward/reverse
switch.
switch control disabled
during the work.
forward/reverse by using the
forward/reverse switch.
work to MC.
forward/reverse by using the
forward/reverse switch during
the work.
• Although the forward/reverse
selector switch is turned ON
and the forward/reverse
switch indicator on monitor
lights during the work, the
machine does not travel
forward/reverse.
forward/reverse by using the
forward/reverse switch during
the work.
• Although the forward/reverse
selector switch is turned ON,
the forward/reverse switch
indicator on monitor does not
light during the work.
Fan Reversing Switch
• Sends the command signal
• The hydraulic drive fan
• Although the switch is turned
Ride Control Switch
• Sends the command signal
• Ride control cannot be
• Altough the ride control
• The command signal is not
• Emergency steering check
• The lift arm auto level cannot
• Although the switch is turned
Emergency
Check Switch
that the fan motor rotates
reverse to MC.
on ride control to MC.
Steering • Sends the operating
command signal on
emergency steering pump
unit to the monitor unit.
Lift Arm Auto Leveler Set • Sends the operating
command signal on lift arm
Switch (Optional)
auto level to MC.
• Sends the setting signal on
cleaning control cannot be
selected or released.
stopped or operated.
sent to the monitor unit.
• The command signal
continues to be sent to the
monitor unit.
be operated or stopped.
• The lift arm stop position
cannot be set randomly.
lift arm stop position to MC.
T5-6-4
ON, the cooling fan does not
rotate reverse.
• Although the switch is turned
OFF, the cooling fan does not
rotate forward.
• If the switch is turned OFF
and the forward/reverse
switch is operated, engine
speed does not increase.
switch is turned ON, ride
control is not operated.
(Travel speed: 7 km/h)
• Although the ride control
switch is turned OFF, ride
control is not stopped.
operation cannot be
operated.
• Whenever the engine strats,
the emergency steering
pump unit is operated for 30
seconds.
ON, the lift arm does not stop
at the set position.
• Although the switch is turned
OFF, the lift arm stops at the
set position.
TROUBLESHOOTING / Troubleshooting B
Descriptions of Control
(Operational Principle
Section in T/M)
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC: 11905
MC Monitor Item: Implement
FNR switch, Selected speed
gear, Actual speed gear,
Backward alarm, Neutral
signal
• Although the forward/reverse lever is
T2-1
MC Monitor Item: Implement
FNR
selector
switch,
Implement
FNR
mode,
Implement FNR operating
light
• Although the forward/reverse lever is
T2-1
MC Monitor Item: Fan reversing switch
• If the switch is turned ON under the
T2-1, T2-3
MC Monitor Item: Ride control switch
• If the travel speed sensor is faulty, ride
T2-1, T2-3
Monitor Unit Monitor Item:
Emergency steering operation check switch
• When the engine starts, the emergency
T2-1, T2-4
MC Monitor Item: Boom
height kickout switch, Boom
height kickout setup switch,
Ground stop switch, Ground
stop setup switch
• The lift arm auto leveler upward set
T2-1
-
-
NOTE
operated and the forward/reverse switch
operation is disabled during the work,
this contition is normal.
operated and the command signal from
forward/reverse selector switch is
disabled during the work, this contition is
normal.
certaion conditions, the fan reversing
control cannot be operated.
• If the key switch is turned OFF and the
fan reversing switch is turned OFF, turn
the key ON in 10 seconds. If not, the fan
reversing control is operated on the
logic in MC. When the switches
cprresponding to travel are operated,
engine speed is fixed to the idling
speed. This condition is normal.
control is disabled.
-
steering pump unit is operated for 2
seconds. This condition is normal.
-
-
switch and lift arm auto leveler
downward set switch are installed.
• Each lift arm auto leveler set switch
consists of the auto leveler ON/OFF
switch and lift arm stop position setup
switch.
• The lift arm stop position cannot be set
without learning the angle sensor. (Refer
to T4-6.)
T5-6-5
TROUBLESHOOTING / Troubleshooting B
Parts
Function
Accelerator Pedal Sensor
Coolant
Sensor
• Sends the command signal
on accelerator depressing to
MC.
Temperature • Detects coolant temperature
by ECM2 and sends the
signal to the monitor unit by
ECM1.
Hydraulic Oil Level Sen- • Sends the signal on hydrauli
oil level to the monitor unit.
sor
Air
Filter
Restriction • Sends the signal on air filter
in-take pressure to the
Switch
monitor unit.
Fuel Level Sensor
Symptoms in control
system when trouble occurs.
• MC fixes -1engine speed to
• As the accelerator pedal is
• Coolant temperature cannot
• Auto warming-up control is
1000 min .
be detected.
operated abnormally.
• The coolant temperature
• Hydraulic oil level cannot be
• The brake oil indicator is
• Air filter in-take pressure
• The air filter restriction
detected.
cannot be detected.
detected.
Hydraulic Oil Tempera- • Sends the signal on hydraulic
oil temperature to MC.
ture Sensor
depressed and engine speed
does not increase, the
machine moves slowly.
gauge is operated
abnormally.
• Sends the signal on fuel level • Fuel level cannot be
to the monitor unit.
Symptoms in machine
operation when trouble
occurs.
operated abnormally.
indicator is operated
abnormally.
• The fuel gauge is operated
abnormally.
• Hydraulic oil temperature
• Hydraulic drive fan cooling
cannot be detected.
• MC fixes the cooling fan to
the maximum speed.
• Engine auto warming-up
control cannot be operated.
• Altough outside air
temperature is high, auto
warming-up control is
operated.
control cannot be operated.
(Cooling fan: Maximum
speed)
• The hydraulic oil temperature
indicator is operated
abnormally.
Bucket Proximity Switch
• Uses for bucket auto leveler
• The bar cannot be detected.
• The bucket auto leveler
Lift Arm Proximity Switch
• Uses for lift arm height
• The plate cannot be
• The lift arm height kickout
Lift Arm Angle Sensor • Uses for lift arm auto leveler
control (optional).
(Optional)
• Sends the signal on lift arm
• Lift arm operating angle
• The lift arm auto leveler
Torque Converter Oil • Sends the signal on torque
converter oil temperature to
Temperature
Sensor
the monitor unit.
(Torque Converter Cooler
Piping Upper)
• Torque converter oil
• Hydraulic drive fan cooling
Outside Air Temperature • Sends the signal on air
temperature to the air
Sensor (for Air Condiconditioner controller.
tioner)
• Auto temperature control in
• The cab inside becomes cold
control.
• ON: While the bar is passed
in front, OFF: When the bar
is out of front
kickout control.
• ON: While the plate is
passed in front, OFF: When
the plate is out of front
detected.
cannot be detected.
cannot be used.
cannot be used.
control (optional) cannot be
used.
operating angle to MC.
temperature cannot be
detected.
the air conditioner cannot be
operated.
T5-6-6
control cannot be operated.
(Cooling fan: Maximum
speed)
• The transmission oil
temperature gauge is
operated abnormally.
or hot rapidly.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC: 11103
MC Monitor Item: Required
engine speed deviation, Engine speed deviation, Accelerator pedal,
ECM Monitor Item: Actual
engine speed, Target engine
speed
ECM: 91
Monitor Unit: 13334
ECM1: 107
-
NOTE
• If MC malfunctions, engine speed
cannot be controlled. In this case, if the
accelerator dedal wiring is connected to
ECM1 directly, engine speed control
becomes possible.
ECM Monitor Item: Coolant
temperature
Monitor Unit Monitor Item:
Radiator
coolant
temperature (possible to be
displayed by using the
service mode on monitor)
MC Monitor Item: Service
brake oil level switch
T2-1
T2-1
-
-
-
Monitor Unit Monitor Item:
Air filter restriction
-
-
Monitor Unit Monitor Item:
Fuel level
-
-
MC Monitor Item: Hydraulic
oil temperature (possible to
be displayed by using the
service mode on monitor)
MC: 11901
Descriptions of Control
(Operational Principle
Section in T/M)
T2-1, T2-3
-
-
-
-
T2-1
T2-1
-
-
-
• If the angle sensor learning is not
-
MC Monitor Item: Boom
angle, Angle sensor learning
status
T2-1
completed, the lift arm stop position
cannot be set. (Refer to T4-6.)
T2-1, T2-3, T3-12
-
-
-
-
-
-
T5-6-7
-
TROUBLESHOOTING / Troubleshooting B
Parts
Symptoms in control
system when trouble occurs.
Function
Outside Air Temperature • Sends the signal
temperature to MC.
Sensor (for MC)
on
air
• Air temperature cannot be • Just after the engine starts,
detected.
Torque Converter Input • Sends the signal on torque
converter inlet speed to MC.
Speed Sensor
Symptoms in machine
operation when trouble
occurs.
the air conditioning is weak
with the air conditioner switch
ON. (No cooled wind blows.)
• Torque converter inlet speed • As torque decrese control
cannot be detected.
cannot be operated, the
engine has a load during
combined operation of travel
and front attachment.
• Gear shifting shock may
become big when traveling.
Torque Converter Output • Sends the signal on torque • Torque converter outlet • As torque decrese control
converter outlet speed to MC.
speed cannot be detected.
cannot be operated, the
Speed Sensor
engine has a load during
Transmission
Valve
Control • Is
installed
to
the
transmission.
• Decreases oil presssure from
the drive unit pump and
supplies clutch connection
pressure.
• The spool moves according
to
the
transmission
proportional solenoid valve
and
clutch
connection
pressure is supplied to the
certain clutch pack.
• Speed gear cannot be shifted
normally.
installed
to
the • Speed gear cannot be shifted
Transmission
Propor- • Is
transmission control valve.
normally.
tional Solenoid Valve
• Consists of 6 solenoid valves • Travel speed is fixed to first
for forward, reverse, first
gear, second gear, third gear
and fourth gear. Is operated
by the command signal from
MC and shifts the spool in
transmission control valve.
Transmission Oil
perature Sensor
Tem- • Is
installed
to
the
transmission.
• Sends the signal on oil
temperature to MC.
gear or second gear due to
the abnormal proportional
solenoid valve.
combined operation of travel
and front attachment.
• Gear shifting shock may
become big when traveling
• The following troubles may
occur
according
to
malfunction. As the serious
accident
including
the
transmission break occurs,
judge the trouble carefully.
• Although the forward/reverse
lever is in Neutral, the
machine moves.
• Although the accelerator
pedal is depressed, the
machine moves slowly or
does not move at all. At this
time, although engine speed
increases, the engine has a
heavy load.
• Big shock occurs when
speed gear is shifted.
• Speed gear is fixed to first
gear or second gear.
• Transmission oil temperature • Transmission oil temperature
cannot be detected.
T5-6-8
is not displayed on Dr. ZX
and the monitor.
• Transmission learning cannot
be performed.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC Monitor Item: Outside air
temperature
-
NOTE
• The cooling fan rotates slowly just after
the engine starts. At this time, if the air
conditoner switch is turned ON, the air
conditioning becomes weak. When air
temperature is high and hydraulic oil
and coolant temeprature are low, if the
air conditoner switch is turned ON, MC
increases target fan speed.
MC Monitor Item: Actual
engine speed, Engine speed
deviation, Torque converter
speed ratio
(possible to be displayed by
using the service mode on
monitor)
MC: 11105
-
T2-1, T3-9
-
MC Monitor Item: Torque
converter output speed,
Torque converter speed ratio
MC: 11601
Descriptions of Control
(Operational Principle
Section in T/M)
T2-1, T3-9
-
T3-9
-
-
-
MC: 11414, 11415, 11416,
11417, 11418, 11419
MC monitor Item: T/M clutch
proportional solenoid valve,
T/M clutch proportional solenoid valve FB (for each for
forward, reverse, first gear,
second gear, third gear and
fourth gear)
• If the travel mode siwtch is in Auto, only
T2-1, T3-9
Monitor Unit: 13312
Monitor Unit Monitor Item:
T/M torque converter (possible to be displayed by using
the service mode on monitor)
• If the circuit is shorted, overheating is
T3-9
speed gear which is selected by using
the shift switch can be operated. This
condition is normal.
displayed. (red zone)
T5-6-9
TROUBLESHOOTING / Troubleshooting B
Parts
• MC cannot calculate travel • If the travel speed sensor
• Sends
the
signal
on
trasmission
output
shaft
speed to MC.
• MC cannot calculate travel • Auto gear shifting cannot be
Temperature • Is installed to the axle upper.
• Axle oil temperature cannot • Although axle oil temperature
the
signal
on
trasmission middle shaft
speed to MC.
Travel Speed Sensor
• Sends the siganl on axle oil
speed.
malfunctions, travel speed is
not displayed on the monitor.
speed.
operated.
is over 120 °C, the service
indicator does not light.
• Altough axle oil temperature
is less than 120°C, the
service indicator lights.
be detected.
temperature to the monitor
unit.
Service Brake Pressure • Is installed to the service • MC makes clutch
brake pressure outlet port in
control disabled.
Sensor
front axle.
cut-off
• Sends the signal on pressure
to MC.
Priority
Pump)
Symptoms in machine
operation when trouble
occurs.
Middle • Sends
Transmission
Shaft Sensor
Axle Oil
Sensor
Symptoms in control
system when trouble occurs.
Function
Valve
(Main • Divides main pump delivery • Division
pressure oil into the steering
valve and the control valve
effectively.
of main pump
delievery
pressure
oil
becomes less efficient.
• Although S, N or D in the
clutch cut-off mode switch is
selected, clutch cut-off is not
operated when the brake
pedal is depressed.
• The
steering
or
front
attahment is operated slowy
according to malfunction.
Main
Pump
Delivery • Sends the signal on main • Main pump delivery pressure • Although engine torque
pump delivery pressure to
cannot be detected.
control cannot be operated
Pressure Sensor
MC.
properly, clear malfunction
• MC makes torque decrease
control disabled.
Steering Relief Valve
may not occur except bad
fuel consumption.
• As torque decrease control
cannot be operated, the
engine has a load during
combined operation of travel
and front attachment.
• Is installed to the priority • If the valve is kept open, the • If the valve is kept open, the
valve (main pump) side on
main pump upper.
• Is operated when steering
circuit pressure exceeds the
specification in order to
protect the steering circuit.
priority valve (main pump) is
operated abnormally.
T5-6-10
priority valve (main pump)
spool stops and pressure oil
is supplied to the control
valve. Then, steering is
operated slowly.
• If the valve is kept closed,
the steering circuit may be
damaged.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC: 5160, 5660, 5665,
5670, 5675, 5680, 5685
MC Monitor Item: Middle
gear speed
MC: 11602
MC Monitor Item: Travel
speed, Transmission output
speed
Monitor Unit: 13318
NOTE
Descriptions of Control
(Operational Principle
Section in T/M)
T2-1, T3-9
T2-1, T3-9
-
Monitor Unit Monitor Item:
Axle oil temperature
-
MC: 11312
MC Monitor Item:
brake pressure
Pedal
-
T2-1
-
T2-3, T3-1
MC: 11204
MC
Monitor
Item:
Pump
T2-1, T2-3, T3-1
pressure
-
T2-3, T3-1
-
-
-
T5-6-11
TROUBLESHOOTING / Troubleshooting B
Parts
Implement
Sensor
Symptoms in control
system when trouble occurs.
Function
Pressure • Is installed to piping upper • Pressure cannot be detected.
between main pump and
control valve.
• Sends the signal on pressure
to control valve from main
pump to MC.
• MC makes torque decrease
control disabled.
Negative Control Valve in • Supplies front/rear pressures • Main pump delivery flow rate
at the orifice in neutral circuit
cannot be controlled properly.
Control Valve
in control valve to the main
pump regulator.
pressure
difference
becomes large with the front
attachment in neutral, the
main
pump
regulator
decreases
main
pump
delivery flow rate.
• As
Symptoms in machine
operation when trouble
occurs.
• Although
engine
torque
control cannot be operated
properly, clear malfunction
may not occur except bad
fuel consumption.
• As torque decrease control
cannot be operated, the
engine has a load during
combined operation of travel
and front attachment.
• When travel load is heavy
and the front attachment is
operated, the engine may be
stalled.
• If
pressure
difference
becomes small, there is no
efficiency to the machine
operation. In the long and
medium
terms,
fuel
consumption may become
bad.
• If
pressure
difference
becomes large, the front
attachment and steering are
operated slowly.
Flow Rate Control Poppet • Controls pressure oil flow • Pressure oil flow rate to the • Speed ratio during combined
rate to the bucket cylinder
bucket cylinder cannot be
operation of front attachment
Valve in Control Valve
during combined operation of
controlled properly.
changes.
• Bucket single operation may
bucket and lift arm in order to
operate combined operation
smoothly.
become slow.
Flow Rate Control Se- • Reduces pressure oil flow • Pressure oil flow rate to the • Speed ratio during combined
rate to the bucket cylinder
bucket cylinder cannot be
operation of front attachment
lector Valve in Control
during combined operation of
controlled properly.
changes.
Valve
bucket and lift arm raise in
• Bucket single operation may
order to operate combined
operation smoothly.
become slow.
Steering Valve
• Controls pressure oil flow • The steering cylinder cannot • According to malfunction, the
Steering Accumulator
• Absorbs
Stop Valve
• Stops supplying pressure oil • Pressure oil flow rate to the
rate to the steering cylinder.
pulsation
steering circuit.
in
the
to the steering valve from the
steering pilot valve when the
steering is operated to the
stroke end, comes in contact
with the frame and closes the
valve.
be controlled.
• Pulsation
in the steering
circuit cannot be absorbed.
steering valve from the
steering pilot valve cannot be
controlled.
T5-6-12
troubles may occur including
the steering is operated
slowly,
the
steering
is
operated without operating
the steering hadle, and so
on.
• When the steering is
operated, hunting may occur.
• When
the
steering
is
operated, hunting occurs
easily.
• When the valve is kept open,
although the steering is
operated to the stroke end,
the steering handle can be
operated.
• When the valve is kept
closed, the steering handle is
operated hardly or cannot be
operated.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
MC: 11209
MC Monitor Item: Implement
pressure
NOTE
Descriptions of Control
(Operational Principle
Section in T/M)
-
-
If pressure becomes small, pump delivery
2
pressure becomes over 2 Mpa (20kgf/cm )
when the engine speed is at fast idle in
neutral.
-
T2-3, T3-2
-
T2-3, T3-2
-
-
-
T2-3, T3-2
-
-
-
T2-3, T3-5
-
-
-
-
-
-
T2-3
T2-3
-
-
-
T5-6-13
TROUBLESHOOTING / Troubleshooting B
Parts
Function
Symptoms in control
system when trouble occurs.
Symptoms in machine
operation when trouble
occurs.
cannot be controlled properly.
troubles may occur including;
although the steering handle
is
operataed
fast,
the
steering is operated slowly,
although the steering handle
is operataed slowly, the
steering is operated fast, and
so on.
• Ride control is not operated.
(Shock when traveling is
continued.)
• Ride control does not stop.
(Shock when traveling is
always reduced.)
Steering Pilot Valve
• Controls pilot pressure oil • Pilot pressure oil flow rate • According to malfunction, the
Ride Control Valve
• Supplies
Emergency
Steering
Pressure Switch
Emergency
Steering
Pump Delivery Pressure
Switch
Hydraulic Fan Motor
flow rate and direction to the
steering valve spool end
according to steering handle
operating
speed
and
direction.
lift arm cylinder
bottom pressure to the
accumulator through the
chage cut-off spool with the
ride control switch OFF.
• Closes the charge cut-off
spool and blocks the circuit
to lift arm cylinder bottom
side
when
accmulated
pressure in the accumulator
exceeds the specification.
• Operates the solenoid valve
by the command signal from
MC, moves the main spool
and connects the circuits
between lift arm cylinder
bottom side and accumulator,
between lift arm rod side and
hydraulic oil tank when travel
speed reaches 7km/h or
faster with the ride control
switch ON.
• Is installed to emergency
steering block in circuit upper
between main pump and
steering valve.
• Sends the signal on steering
circuit pressure to the
monitor unit.
• Is installed to between
emergency steering pump
and emergency steering
block.
• When pressure oil beyond
specification
from
the
emergency steering pump is
supplied, the connection is
broken and the monitor unit
judges that the emergency
steering switch is operated
correctly.
• Operates the flow rate
adjustment solenoid valve by
the command signal from
MC. Controls pressure oil
flow rate to the fan motor by
operating the flow rate
control valve. Increases or
decreases cooling fan speed.
• Operates the reverse control
solenoid
valve
by
the
command signal from MC.
Shifts the outlet port for
pressure oil to the fan motor
by operating the reverse
control valve. Switches the
cooling fan in reverse
rotation.
• Pressure
cannot
be
accumulated
in
the
accumulator.
• The solenoid valve and main
spool cannot be controlled.
• Steering
• Although there is no trouble
• The
• Although
circuit pressure
cannot be detected.
normal
signal
on
pressure occurrence is not
sent to the monitor unit.
in the steering circuit, the
emergency steering pump is
operated.
the emergency
steering pump auto check
circuit is operated when the
engine starts, the emergency
steering
pump
indicator
blinks.
• The flow rate control valve • Cooling fan speed cannot be
cannot be controlled.
controlled.
cannot be controlled.
cannot be operated.
• The reverse control valve • Cooling fan reverse control
T5-6-14
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
NOTE
Descriptions of Control
(Operational Principle
Section in T/M)
T2-3, T3-4
-
-
-
MC Monitor Item: Ride control proportional valve output, Ride control proportional
valve output FB
• If the travel speed sensor malfunctions,
T2-1, T2-3, T3-8
Monitor Unit Monitor Item:
Steering pressure
• Altough the emergency steering pump is
T2-3, T2-4, T3-12
MC makes ride control disabled.
-
Monitor Unit: 13313
operated for 2 seconds when the engine
starts, this condition is normal.
Monitor Unit Monitor Item:
Emergency steering pump
pressure switch
T2-3, T2-4
-
MC: 11412
-
T2-1, T2-3, T3-3
MC Monitor Item: Hydraulic
fan target speed, Hydraulic
drive fan proportional valve,
Hydraulic
drive
fan
proportional
valve
FB,
Hydraulic drive fan reverse
valve
-
T5-6-15
TROUBLESHOOTING / Troubleshooting B
Parts
Symptoms in control
system when trouble occurs.
Function
Symptoms in machine
operation when trouble
occurs.
Charging Block
• Divides pilot pump pressure • Stable pressure cannot be • The
Priority Valve (Charging
Block)
• Is installed in the charging • Stable pressure cannot be • The
Primary Brake Pressure
Sensor
• Is installed in the charging • Accumulated pressure in the • The
Service
Valve
Relief
• Is installed in the charging • Accumulated pressure in the • According to malfunction, the
Pump Torque Control
Proportional
Solenoid
Valve
• Is installed in the charging • Pilot pressure to the main • According to malfunction, the
Parking Brake Solenoid
Valve
• Controls
Parking Brake Pressure
Sensor
• Sends the signal on parking • Parking
Brake
oil into the brake circuit and
the pilot circuit effectively.
• Accumulates pressure at
outlets of brake circuit and
pilot circuit and supplies
stable pressure to both
circuits.
block. Divides pilot pump
pressure oil into the brake
circuit and the pilot circuit
effectively.
block. Monitors accumulated
pressure in the service brake
accumulator.
block. Is operated when
accumulated pressure in the
service brake accumulator
exceeds the specification.
• Supplies pilot pump delivery
oil to the pilot circuit after the
priority valve (charging block)
is open.
block. Is operated by the
command signal from MC.
• Supplies pilot pressure for
pump delivery flow rate
control to the main pump
regulator.
that the parking
brake is applied or released.
brake circuit pressure to MC.
supplied to the brake circuit
or the pilot circuit.
supplied to the brake circuit
or the pilot circuit.
the
service
brake
accumulator
cannot
be
detected.
the
service
brake
accumulator
cannot
be
controlled.
pump regulator cannot be
controlled and supplied.
brake oil pressure
indicator lights.
• The parking brake cannot be
released.
• The
front
attachment/
steering
are
cylinders
operated slowly.
brake oil pressure
indicator lights.
• The parking brake cannot be
released.
brake oil pressure
indicator on monitor always
lights.
• Although the trouble in the
service brake circuit due to
pressure decrease, the brake
oil pressure indicator on
monitor does not light.
service
brake
efficinecy
becomes bad or the parts in
service brake circuit are
damaged.
• According to malfunction, the
parking brake is completery
not released or the parts in
parking brake circuit are
damaged.
troubles may occur including
the front attachment/steering
are operated slowly, the
engine
stalled
during
combined operation of front
attachment and travel or
engine idling, and so on.
• The parking brake cannot be • According to malfunction, the
controlled to apply or release.
brake
circuit
pressure cannot be detected.
• MC makes the parking brake
indicator go off forcibly.
• MC makes forward/reverse
operation disabled when the
parking brake is applied.
parking brake cannot
applied or released.
be
• The machine cannot travel
forwad/reverse.
• The parking brake indicator
does not light with the
parking brake switch OFF.
• Although the parking brake is
applied, the machine can
travel.
Electromagnet in Pilot
Valve
• Fixes the control lever by the • The control lever in pilot • Although the electromagnet
Brake Valve
• Supplies
magnetic force when the
electromagnet in pilot valve
is magnetized and the control
lever in pilot valve is moved
to the detent position.
pilot
pressure
according to brake pedal
depression from the outlet
port and operates the service
brake.
valve is not fixed in the
detent position.
• Pilot
pressure
controlled.
T5-6-16
cannot
be
in pilot valve is magnetized,
the control lever is not fixed.
• The service brake does not
function.
TROUBLESHOOTING / Troubleshooting B
Evaluation by Fault
Code
Evaluation by Monitor
Function
NOTE
Descriptions of Control
(Operational Principle
Section in T/M)
T2-3, T3-7
-
-
-
T2-3, T3-7
-
Monitor Unit: 13314
-
-
T2-3, T3-7
Monitor Unit Monitor Item:
Service brake pressure
-
T2-3, T3-7
-
MC: 11413
-
-
T2-1, T2-3, T3-7
MC Monitor Item: Pump displacement proportional valve
output, Pump displacement
proportional valve output FB
-
T2-1, T2-3, T2-4, T3-12
MC: 11313
MC Monitor Item: Parking
brake pressure
Monitor Unit Monitor Item:
Parking brake signal, Parking brake pressure switch
-
-
• The
parking brake body circuit is
separated from the parking brake
operation monitoring circuit. Therefore,
although the parking brake operation
monitoring circuit malfunctions, if the
parking brake body circuit is normal, the
parking brake can be operated.
T2-1, T2-3, T2-4, T3-12
T2-1, T3-6
MC Monitor Item: Boom
height kickout, Ground stop
system
-
T2-1, T2-3, T3-11
-
-
-
T5-6-17
TROUBLESHOOTING / Troubleshooting B
CORRELATION
BETWEEN
TROUBLE
SYMPTOMS AND PART FAILURES
This table indicates the relationship between machine
troubles and parts contributing to the cause of the
trouble if failed.
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
Engine System Troubleshooting
Trouble
Symptom
E-1
Starter does not rotate.
E-2
Even if starter rotates, engine
does not start.
E-3
Engine is difficult to start at
low temperature.
Parts
Battery Relay
z
Glow Relay
Neutral Relay
MC
ECM1, 2
Key Switch
Forward/Reverse Lever
Forward/Reverse Switch
Fan Reverse Switch
Accelerator Pedal Sensor
Main Pump Regulator
Fuel Pump
Pump Delivery Pressure Sensor
Implement Pressure Sensor
z
z
z
z
z
z
z
z
z
{
z
z
Pump Torque Control Proportional
Solenoid Valve
Engine Unit
Engine Electrical Equipment
Remarks
z
Check fuse and battery.
z
Check intake and fuel system.
(filter, piping)
T5-6-18
z
Check fuse and battery.
TROUBLESHOOTING / Troubleshooting B
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
E-4
Even if accelerator pedal is depressed, engine speed remains
unchanged.
z
z
E-5
Even if key switch is turned
OFF, engine does not stop.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
E-6
Engine stalls during operation
under adverse condition such as
at high altitude.
z
z
{
z
z
z
z
z
z
z
z
Check wiring
pedal sensor.
{
z
of
accelerator
Check fuse and battery.
T5-6-19
TROUBLESHOOTING / Troubleshooting B
Front Attachment System Troubleshooting
F-1
Trouble
All front attachments does not
Symptom
move.
Parts
F-2
All front attachment operations are slow/ weak.
MC
ECM
Shift Switch
Work Mode Selector Switch
Accelerator Pedal Sensor
Lift Arm Proximity Switch
Torque Converter Input Speed Sensor
F-3
Certain front attachment is
slow/ weak.
z
{
{
Torque Converter Output Speed Sensor
Main Pump
Main Pump Regulator
Priority Valve (Main Pump)
Main Pump Delivery Pressure Sensor
Steering Relief Valve
Pilot Pump
Implement Pressure Sensor
Control Valve Spool
Main Relief Valve in Control Valve
Overload Relief Valve in Control Valve
z
{
z
z
z
z
{
{
{
{
z
{
z
Load Check Valve in Control Valve
z
Make-Up Valve in Control Valve
z
Restriction Valve in Control Valve
z
Flow Rate Control Poppet Valve in
Control Valve
z
Flow Rate Control Selector Valve in
Control Valve
z
Cylinder
z
Steering Valve
{
Steering Pilot Valve
{
Charging Block
z
Priority Valve (Charging Block)
z
Service Brake Relief Valve
Pilot Relief Valve
z
{
z
Pump Torque Control Proportional Solenoid Valve
z
Pilot Valve
z
Electromagnet in Pilot Valve
Pilot Shut-Off Valve
z
z
Engine Unit
z
Engine Electrical Equipment
z
Remarks
Check fuse and battery.
T5-6-20
TROUBLESHOOTING / Troubleshooting B
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
F-4
Front attachment moves
with lever in neutral.
F-5
Front attachment drifts
remarkably.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
F-6
Bucket is slow during
combined operation.
F-7
Work mode is not effective.
F-8
Lift arm height kickout is
not operated.
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
{
z
z
z
When the engine stops.
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-21
TROUBLESHOOTING / Troubleshooting B
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
Trouble Symptom
F-9
Lift arm float is
not operated.
F-10
Bucket auto leveler
is not operated.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
F-11
Lift arm auto lever is
not operated. (optional)
F-12
Lift arm auto lever
stop position cannot be set. (optional)
F-13
Ride Control is not
effective.
z
z
z
Parts
MC
Ride Control Switch
z
Lift Arm Auto Leveler Set
Switch (Optional)
Bucket Proximity Switch
z
z
z
z
z
Lift Arm Angle Sensor (Optional)
Travel Speed Sensor
Control Valve Spool
z
{
Overload Relief Valve in Control Valve
{
Cylinder
Ride Control Valve
Charging Block
Priority Valve (Charging Block)
Service Brake Relief Valve
Pilot Relief Valve
Electromagnet in Pilot Valve
{
z
{
{
{
{
z
z
z
When the lift arm angle
sensor does not learn
and the stop position is
not set, lift arm auto
leveler is not operated.
Remarks
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-22
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-23
TROUBLESHOOTING / Troubleshooting B
Travel System Troubleshooting
Trouble
Symptom
T-1
Machine does
travel
ward/reverse.
not
for-
T-2
Machine does not
travel forward or reverse.
T-3
Machine moves with
lever in neutral.
T-4
Even if travel speed is
turned up or down,
travel speed gear is
not changed.
z
z
z
z
z
Parts
MC (Main Controller)
Forward/Reverse Lever
Shift Switch
Travel Mode Selector Switch
Down-Shift Switch
Down-Shift/Up-Shift Switch
Hold Switch
Forward/Reverse Switch
Forward/Reverse Selector Switch
Drive Unit Charging Pump
Torque Converter
Transmission Control Valve
Transmission
Valve
Proportional
z
z
z
z
z
z
z
z
Solenoid
Transmission
Travel Speed Sensor
Axle
Service Brake
Service Brake Pressure Sensor
Propeller Shaft
Parking Brake Pressure Sensor
Brake Valve
Engine Unit
Engine Electrical Equipment
{
{
z
{
z
z
{
{
Remarks
T5-6-24
z
z
z
z
z
z
z
z
z
z
z
z
TROUBLESHOOTING / Troubleshooting B
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
T-5
T-6
T-7
Even if up-shift switch is Even if down-shift switch Even if hold switch is
pushed, travel speed gear is pushed, travel speed pushed, travel speed gear
is not turned up.
gear is not turned down.
is not fixed.
z
{
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-25
TROUBLESHOOTING / Troubleshooting B
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
Trouble
Symptom
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
T-9
T-8
Travel mode is not Clutch cut-off is not
shifted.
operated.
Parts
MC (Main Controller)
Monitor Unit
Travel Mode Selector Switch
Clutch Cut-off Position Switch
Torque Converter Input Speed Sensor
Torque Converter Output Speed Sensor
Travel Speed Sensor
Service Brake Pressure Sensor
z
z
z
z
z
z
{
{
{
z
Remarks
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-26
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-27
TROUBLESHOOTING / Troubleshooting B
Brake System Troubleshooting
Trouble
Symptom
B-1
B-2
B-3
Parking brake is not
released.
Parking brake is
not locked.
Service brake efficiency is bad or
low.
Parts
Parking Brake Relay 1
Parking Brake Relay 2
Monitor Unit
Parking Brake Relay Switch
Parking Brake
Service Brake
Pilot Pump
Charging Block
Priority Valve (Charging Block)
Service Brake Relief Valve
Pilot Relief Valve
Parking Brake Solenoid Valve
Brake Valve
Engine Electrical Equipment
z
z
z
z
z
z
z
z
z
{
{
{
{
{
z
z
z
z
{
Remarks
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-28
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-29
TROUBLESHOOTING / Troubleshooting B
Steering/Other System Troubleshooting
Trouble
H-1
Symptom
Steering cylinder operation is slow or does
not move.
Parts
Main Pump
Main Pump Regulator
Priority Valve (Main Pump)
Steering Relief Valve
Pilot Pump
Cylinder
Steering Valve
Steering Overload Relief Valve
Stop Valve
Steering Pilot Valve
Charging Block
Priority Valve (Charging Block)
Pilot Relief Valve
Other Electrical Equipment
O-1
Air conditioner operation
malfunctions.
{
{
z
z
{
z
z
z
z
z
{
{
{
z
Check if the steering
shaft is normal.
Remarks
z : Related, required to check
{ : Related. However, in case this component fails, other trouble
symptom will be more noticeable so that this component will not
be the direct cause of the trouble concerned.
T5-6-30
NOTE: The trouble symptoms in this table are described provided that each trouble occurs
independently.
In case more than one trouble occurs at
the same time, find out all faulty components while checking all suspected components in each trouble symptom.
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-31
TROUBLESHOOTING / Troubleshooting B
ENGINE SYSTEM TROUBLESHOOTING
E-1 Starter does not rotate.
IMPORTANT: The starting signal from ECM2 is
not routed to the starter with the
forward/reverse lever or forward/reverse switch in Forward
or Reverse position, the starter
does not rotate. (Refer to “Electrical System / SYSTEM”.)
• Check the wiring connections first.
YES
Switch neutral relay
YES with other general relay.
Check if starter rotates.
· Key switch: START
Check if both voltages
YES at key switch terminals #5 and #6 are 24
V.
Faulty neutral relay.
Remove neutral relay.
Check if voltages at terminal #1 of harness end
NO of connector and terminal
BR in battery relay are 24
V respectively.
· Key switch: ON
· Key switch: ON
YES Faulty key switch.
Check if battery voltage
and electrolyte density is
normal, and fusible link
(120 A) is not blown.
NO
· Voltage: 24 V or more
Density: 1.26 or more
Check for continuity
between battery positive terminal and key
switch terminal #1.
· Key switch: ON
NO
Faulty fuse or harness
between battery and key
switch.
Faulty battery or faulty
fusible link.
NO
Key Switch:
Battery Relay:
#6
#1
#5
T105-07-04-002
Terminal BR
T5-6-32
T178-05-04-001
TROUBLESHOOTING / Troubleshooting B
Disconnect connector
ECM 1-A in ECM.
Connect terminal #A1
of harness end of connector to vehicle
YES frame.
Check for continuity
between terminal #3 of
harness end of connector in neutral relay
and vehicle frame.
Disconnect connector ECM1-C in ECM1
and 16pin connector
in ECM 2.
Check if voltages at
YES terminal #C1 of harness end of connector ECM1-C and terminal #8 of harness
end of 16pin connector in ECM2 are
24 V respectively.
Connect connector
ECM1-A.
Check for continuity
YES between terminal #4
of harness end of
connector in neutral
relay and vehicle
frame..
· Key switch: ON
YES
NO
To A
Faulty harness between
ECM1 and key switch or
between ECM2 and key
switch.
Open circuit in harness
between neutral relay
and ground.
NO
Open circuit in harness
between neutral relay
and ECM1.
NO
Faulty fuse or open circuit
in harness between key
switch and neutral relay
or between key switch
and battery relay.
NO
Connector (Harness end of connector viewed from the
open end side)
Neutral Relay
#4
#1
#3
T183-05-04-003
ECM2 16Pin Connector
Connector ECM1-C
Connector ECM1-A
#A1
#C1
#8
13
15
1
3
10
12
1
3
T5-6-33
1
8
9
16
TROUBLESHOOTING / Troubleshooting B
NO
A
Check for continuity
between terminal #2 of
harness end of connector in neutral relay
and vehicle frame.
· Key switch: ON
Disconnect harness
from terminal A in
YES battery relay.
Check for continuity
between disconnected harness and
vehicle frame.
Connect neutral relay.
Check if voltage at
terminal A in battery
relay is 24 V.
YES
Bへ
Faulty harness between battery relay
NO and starter motor.
· Key switch: OFF
· Key switch: ON
Faulty battery relay.
NO
Monitor FNR SW of
monitoring item in
Dr. ZX.
Operate forward/reverse lever.
YES Check if FNR display on Dr. ZX
screen is changed
according to operation.
Shorted circuit in
harness between
neutral relay and MC
or faulty MC.
YES
Faulty harness between forward / reverse lever and MC
or faulty forward/reverse lever.
NO
· Key switch: ON
Faulty harness between ECM 2 and
starter motor, or
faulty ECM 1 or 2.
NO
B
Disconnect harness
from terminal S in
starter motor.
Check if voltage is
generated.
· Key switch: Start
Faulty starter motor.
YES
Connector (Harness end of connector viewed from the
open end side)
Battery Relay:
Terminal A
Neutral Relay
#2
Connector MC-C
C1
C23
T183-05-04-003
T178-05-04-001
T5-6-34
#C9
C10
C31
TROUBLESHOOTING / Troubleshooting B
E-2
Even if starter rotates, engine does not
start.
Related MC Fault Code: None
• Check the wiring connections first.
• Check if fuel system malfunctions, the fuel filter is
clogged or the fuel pump is properly operated
with the key ON.
Refer to Troubleshooting A.
YES
Execute
self-diagnosing of
each controller by
using Dr. ZX.
Check if any fault
code is displayed.
Refer to Engine
Troubleshooting
Manual.
NO
T5-6-35
TROUBLESHOOTING / Troubleshooting B
E-3
Engine is difficult to start at low temperature. (During cold weather or in cold districts, engine is difficult to start or does
not start even if pre-heated.)
• Check if electricity is routed to the intake-air
heater. Check the intake-air heater for any abnormality.
• Check the battery.
• Check the wiring connections first.
NOTE: If there is no malfunction on the fol-
lowings and the engine is difficult to
start with the engine cold, the fuel
pump performance may become bad.
Faulty coolant temperature sensor.
YES
Replace coolant temperature
sensor and intake-air combination sensor with normal
ones.
Check if voltage at intake-air
heater is 20 to 24 V.
· Key switch: ON
· Connect to machine from
the back of connector by
using a clip with the connector connected.
NO
YES
Faulty ECM1.
NO
Disconnect connector in
intake-air heater.
Measure each glow plug
resistance.
Connect terminal #C10 of
connector ECM1-C in ECM1
to vehicle frame.
Check if problem is cor· Connect to machine from
the back of connector by
using a clip with the connector connected.
· Key switch: OFF
Connector (Harness end of connector viewed from
the open end side)
Connector ECM1-C
Glow Relay Connector
#C10
10
1
12
3
#1
#4
#3
T183-05-04-003
T5-6-36
TROUBLESHOOTING / Troubleshooting B
250 mΩ or higher
Faulty glow plug.
NO
YES
Connect connector in
glow relay.
Connect terminal #4 of
harness end of connector
to vehicle frame.
Check if voltage at intake-air heater is 20 to 24
· Key switch: ON
YES
Faulty glow relay, or
faulty harness between
glow relay and intake-air
heater.
Open circuit in harness
between glow relay and
ECM1.
Disconnect connector in
glow relay.
Check if voltages at terLess than 250 m Ω minals #1 and #3 of harness end of connector in
glow relay are 20 to 24 V.
· Key switch: ON
If terminal #1 is 0 V, open
circuit in 120A fuse or
harness between glow
relay and battery. If terminal #3 is 0 V, open
circuit in fuse or harness
between glow relay and
terminal M in key switch.
NO
T5-6-37
TROUBLESHOOTING / Troubleshooting B
E-4 Even if accelerator pedal is depressed, engine speed remains unchanged.
Related MC Fault Code: 11004-2, 11101-3, 11101-4
• Check the wiring connections first.
• Turn the key switch OFF with the fan reversing
switch ON. Turn the fan reversing switch OFF
within 10 seconds and start the engine. When the
machine travels, engine speed is fixed to idling
speed. This condition is normal. Although the fan
reversing switch is OFF, if the same trouble occurs, harness to the fan reversing switch or MC
may be shorted.
Faulty accelerator pedal,
or open circuit in harness
between accelerator
pedal and MC.
YES
Check if fault code 11101-3 or
11101-4 is displayed.
Monitor accelerator pedal
(standard voltage) by using
Dr. ZX.
Check if voltage is normal.
· Key switch: ON
· Standard voltage
Slow idle position: 0.3 to 1 V
Fast idle position: 4.0 to 4.7 V
YES
NO
Faulty CAN between MC
and ECM1.
Check if fault code 11004-2 is
displayed at the same time.
· Key switch: ON
Faulty MC.
NO
T5-6-38
TROUBLESHOOTING / Troubleshooting B
E-5 Even if key switch is turned OFF, engine
does not stop.
• Check the wiring connections first.
• The trouble that even if accelerator pedal is
depressed, engine speed remains unchanged may occur. Execute the troubleshooting procedures on this trouble.
YES
Faulty key switch.
Check if voltage at
terminal #5 in key
switch is 24 V.
Shorted circuit in
harness between
key switch and
NO
· Key switch: OFF
NO
Disconnect connector
ECM1-D in ECM1.
Check if voltage between terminal #D2 of
harness end of connector and vehicle
frame is 0 V.
Faulty ECM1.
· Key switch: OFF
Key Switch:
YES
Connector (Harness end of connector viewed from the
open end side)
Connector ECM1-D (Harness end)
#5
T105-07-04-002
T5-6-39
19
1
21
3
#D2
TROUBLESHOOTING / Troubleshooting B
E-6 Engine stalls during operation under adverse condition such as at high altitude.
Related MC Fault Code: 11004-2, 11910-2, 11209-3,
11209-4,11413-2, 11413-3,11413-4
• Check the wiring connections first.
• Check if fuel system malfunctions, the fuel filter is
clogged or the fuel pump is properly operated
with the key ON.
Faulty pump delivery
pressure sensor, implement pressure
sensor or pump
torque control solenoid valve.
YES
Check if fault code
NO 11204-3, 11204-4,
11209-3, 11209-4,
11413-2, 11413-3 or
11413-4 is displayed.
Monitor pump torque
control solenoid valve
output. Install a pressure gauge to output
port.
Check pressure values
on Dr. ZX and pressure gauge.
Check if pressure increases or decreases
with both pressure in
equal.
· Engine: Running
NO
Monitor actual engine
speed.
Check if abnormal engine speed is detected.
Faulty pump torque
NO control solenoid
valve, or open circuit
in harness to MC.
Disassemble and
check main pump
YES regulator.
· Engine: Running
· MC monitor item: Pump
displacement proportional
valve output
· Refer to Operational Performance Test section.
· Engine: Running
· MC monitor item: Actual
engine speed
Refer to fault code
11004-2 in Troubleshooting A.
YES
Check if fault code
YES 11004-2 is displayed.
YES Refer to Engine Troubleshooting Manual.
· Engine: Running
Check if fault code
NO 11910-2 is displayed.
· Engine: Running
Faulty MC.
NO
T5-6-40
TROUBLESHOOTING / Troubleshooting B
FRONT ATTACHMENT SYSTEM TROUBLESHOOTING
F-1 All front attachments do not move.
YES
Faulty pilot shut-off
valve.
Check if pressure
at port P in pilot
shut-off valve is
within specification.
YES
· Specification:
3.7+0.5−03 Mpa (38+5−3
kgf/cm2)
NO
Normal.
Disassemble and
clean pilot valve.
Check if machine
operation is normal.
Faulty pilot pump.
NO
T5-6-41
TROUBLESHOOTING / Troubleshooting B
F-2 All front attachment operations are slow /
weak.
• When the service brake valve is kept closed, trouble
may occur. In this case, as the pilot hose or pilot filter is
damaged, this is not included here.
Internal leakage in
steering pilot valve.
YES
Remove hose connected to port P in
steering pilot valve.
NO Install a plug.
Check if front cylinder operating time
is within specification.
While raising lift
arm cylinder, turn
YES
steering handle.
Check if lift arm
speed decreases.
Check if travel performance is within
specification.
· Engine: Running
· Refer to Operational Performance Test section.
· Engine: Running
· Refer to Operational Performance Test section.
Remove hose
connected to port
LS in priority valve
Clogging between port
(main pump). In- YES
LS and drain port in
stall a plug. Install
steering valve.
drain hose to port
LS. Put oil into oil
NO pan. Check if lift
arm cylinder operating time is
Stuck spool in priority
within specificaNO valve (main pump).
tion.
· Engine: Running
· Refer to Operational PerformYES
To A
ance Test section.
· Engine: Running
Check if pressure
YES at port A4 in pilot
shut-off valve is
within specification.
Faulty pilot shut-off
valve.
· Engine: Running
NO
· Pilot shut-off lever:
Check if pressure at
ON
port P in pilot
· Specification:
shut-off valve is
3.7+0.5−03 Mpa
YES within specification.
Stuck check valve or
(38+5−3 kgf/cm2)
priority valve in charg· Engine: Running
YES ing block, faulty pilot
· Pilot shut-off lever:
pump or clogged pilot
ON
Disassemble,
filter.
· Specification:
+0.5
clean
and
adjust
3.7 −03 Mpa
pilot relief valve.
(38+5−3 kgf/cm2)
NO Check if trouble
occurs.
End
· Engine: Running
NO
Refer to Engine Troubleshooting Manual.
YES
Operate accelerator pedal.
NO Check if engine
speed changes.
Refer to “E-4 Even if
accelerator pedal is
depressed, engine
speed remains unchanged” in this group.
· Engine: Running
NO
T5-6-42
TROUBLESHOOTING / Troubleshooting B
YES
A
Check if main relief
pressure is within
specification.
Monitor pump displacement proportional solenoid valve
output of MC monitor
item by using Dr. ZX.
Check if output is 1
MPa (10 kg/cm2) or
less.
· Accelerator pedal:
Fully depressed
· Front attachment:
Operated
· Engine: Running
· Refer to Operational Performance Test section.
YES
NO
Faulty MC.
Check if pressure at
port ST in main pump
regulator is 2 MPa (20
kg/cm2) or more.
· Accelerator pedal:
Fully depressed
· Front attachment:
Operated
Faulty main relief
valve.
NO
Open circuit in harness in pump torque
control solenoid valve
or stuck spool.
YES
B
YES
End.
Disassemble and
clean main pump
regulator.
NO Check if front attachment operation is
normal.
Faulty main pump.
NO
T5-6-43
To B
TROUBLESHOOTING / Troubleshooting B
F-3 Certain front attachment is slow / weak.
• If the lift arm or the bucket is normal, the pilot
pump (primary pilot pressure) should be normal.
• If there is malfunction in the pilot poppet valve in
main relief valve, operating speed with light load
may be normal.
YES
Check if bucket op-
YES eration is worse only
during combined
operation of lift arm
raise and bucket.
YES
NO
Check if overload
relief valve pressure
is normal.
Stuck spool in control
valve or faulty cylinder
(faulty seal kit).
· In case of lift arm, load
check valve may be
stuck.
· Refer to Operational
Performance Test
section.
Check if secondary
pilot pressure in pilot
circuit which trouble
occurs is normal.
Clogged or stuck
bucket flow rate control valve (check, orifice, spool).
NO
Faulty overload relief
valve or make-up
valve.
· Engine: Running
· Secondary pilot pressure: Refer to operational Performance
Test section.
Faulty pilot valve.
NO
· In case of lift arm, restriction valve may be
stuck.
T5-6-44
TROUBLESHOOTING / Troubleshooting B
F-4 Front attachment moves with lever in neutral.
• Although the lever is released just after the lift
arm is operated, the lift arm is kept moving. In
this case, the restriction valve may be clogged.
YES
Faulty pilot valve.
NO
Stuck spool in control
valve.
Turn pilot shut-off
valve to LOCK position.
Check if lift arm stops.
· Engine: Running
T5-6-45
TROUBLESHOOTING / Troubleshooting B
F-5 Front attachment drifts remarkably.
YES
Check if cylinder drift
in each front attachment is within specification.
· Engine: Running
· Refer to Operational
Performance Test
section.
Normal.
NO
NO
Lock pilot shut-off
valve.
Check if symptom
disappears.
Replace with other
overload relief valve
temporarily.
Check if symptom
disappears.
· Engine: Running
· Engine: Running
Faulty pilot valve.
YES
• Lift Arm Cylinder Internal Leakage Check
1. With the bucket cylinder slightly extended from
the fully retracted position, lower the bucket tooth
tips onto the ground.
2. Remove the hoses from the lift arm cylinder rod
side. Drain oil from the hoses and cylinders.
(Plug the remove hose ends.)
3. Retract the bucket cylinder rod and lift the bucket
off the ground. If oil flows out of the hose removed pipe ends and the lift arm cylinders are
retracted at this time, oil leaks in the lift arm cylinders. In case no oil flows out of the hose removed pipe ends but the lift arm cylinders are retracted, oil leaks in the control valve.
T5-6-46
T4GB-05-04-001
TROUBLESHOOTING / Troubleshooting B
NO
Scored control valve
spool, broken spring, or
loose spool end.
NO Check if oil leaks
in cylinders.
· Refer to the followings.
YES
YES
Faulty cylinder. (Replace
seal kit.)
Faulty overload relief
valve.
T5-6-47
TROUBLESHOOTING / Troubleshooting B
F-6 Bucket is slow during combined operation.
YES
NO
Check if each cylinder
speed in front attachment is normal.
· Engine: Running
· Refer to Operational
Performance Test
section.
Check if bucket operation is slow during
combined operation of
lift arm raise and
bucket.
NO
Faulty flow rate control
selector valve in control
valve.
Faulty bucket flow rate
control poppet valve in
control valve.
Refer to “F-3 Certain
front attachment is slow/
weak” in this group.
YES
T5-6-48
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-49
TROUBLESHOOTING / Troubleshooting B
F-7 Work mode is not effective.
• Check the corresponding wiring and connectors
in electrical parts.
• When the work mode switch malfunctions, the
remarkable trouble does not occur. As fuel consumption becomes bad, this trouble may come
out.
• When the work mode selector switch is shifted,
engine torque control (refer to the Control System group/SYSTEM.) is executed. If the parts
corresponding to this control malfunction, the
fault code is displayed. Execute the remedy according to troubleshooting A.
• Although the fault code is not displayed and fuel
consumption becomes bad, refer to Engine Troubleshooting Manual and inspect the engine.
T5-6-50
TROUBLESHOOTING / Troubleshooting B
F-8 Lift arm height kickout is not operated.
• Check the wiring connections first.
Connect terminal #2 of
harness end connector YES
in electromagnet at lift
arm raise side to vehicle frame.
Raise and lower lift
arm.
YES
While plate is located
in front of proximity
switch, check if there is
continuity.
Or while plate is away
from proximity switch,
check if there is disNO
continuity.
Disconnect connector
in electromagnet at lift
arm raise side in pilot
valve. Ground terminal #1 of harness end
connector to vehicle
frame. Check if voltage is 24 V.
· Engine: Running
· If one is YES, go to NO.
Faulty electromagnet
at lift arm raise side.
Disconnect connector in lift arm proximity switch.
Check for continuity
in same procedures
as former ones.
Check if results are
same to former ones.
· Engine: Running
YES
NO
Shorted or open circuit
in harness between lift
arm proximity switch
and electromagnet at
lift arm raise side, or
open circuit in harness
between lift arm
proximity switch and
ground.
Faulty lift arm proximity switch.
· Engine: Running
Faulty fuse or faulty
harness between fuse
box B and electromagnet at lift arm
raise side.
NO
Connector (Harness end of connector viewed from the
open end side)
Electromagnet Connector at
Lift Arm Raise Side
#1
#2
1
2
T5-6-51
TROUBLESHOOTING / Troubleshooting B
F-9 Lift arm float is not operated.
• Check the wiring connections first.
YES
YES
Disconnect connector in electromagnet
at lift arm lower side
in pilot valve.
Connect terminal #2
of harness end connector to vehicle
frame.
Check for continuity.
Connect terminal #1 of
harness end connector
in electromagnet at lift
arm lower side to vehicle frame.
Check if voltage is 24 V.
· Engine: Running
NO
NO
Connector (Harness end of connector viewed from the
open end side)
Electromagnet Connector at Lift
Arm Lower Side
#2
1
Faulty fuse or faulty
harness between fuse
box B and electromagnet at lift arm
lower side.
Open ground circuit in
electromagnet at lift
arm lower side.
· Engine: Running
#1
Faulty electromagnet
at lift arm lower side.
2
T5-6-52
TROUBLESHOOTING / Troubleshooting B
F-10 Bucket auto leveler is not operated.
• Check the wiring connections first.
Disconnect connector in
electromagnet at bucket
tilt side in pilot valve.
Ground terminal #1 of
harness end connector
to vehicle frame.
Check if voltage is 24 V.
Connect terminal #2
of harness end connector in electromagnet at bucket tilt
side to vehicle frame.
Operate bucket.
While bar is located
YES in front of proximity
switch, check if there
is continuity.
Or while bar is away
from proximity
switch, check if there
is discontinuity.
· Engine: Running
· If one is YES, go to
NO.
YES
NO
Faulty electromagnet
at bucket tilt side.
Disconnect connector in bucket proximity switch.
Check for continuity
in same procedures
as former ones.
Check if results are
same to former ones.
· Engine: Running
YES
NO
Shorted or open circuit
in harness between
bucket proximity
switch and electromagnet at bucket tilt
side, or open circuit in
harness between
bucket proximity
switch and ground.
Faulty bucket proximity switch.
· Engine: Running
Faulty fuse or faulty
harness between fuse
box B and electromagnet at bucket tilt
side.
NO
Connector (Harness end of connector viewed from the
open end side)
Electromagnet Connector at
Bucket Tilt Side
#1
#2
1
2
T5-6-53
TROUBLESHOOTING / Troubleshooting B
F-11 Lift arm auto leveler is not operated. (Optional)
• Check the wiring connections first.
YES
Check if boom angle of
MC monitor item by
using Dr. ZX is
3.78±0.5 V with lift arm
at highest position.
YES
Check if success is
displayed on angle
sensor learning status
of MC monitor item by
using Dr. ZX.
YES
· Put the matching
mark on lift and shaft
by using a white pen.
Operate the lift arm
several times in order
to check.
To B
NO
· Engine: Running
· Lift arm auto leveler
switch: ON (2 used)
Raise and lower lift
arm.
Check arm angle
sensor shaft rotates
according to link.
To A
Execute lift arm angle
sensor learning.
NO
· Refer to the Operational
Performance Test
Tighten link bolt.
NO
· Rotate the shaft where
boom angle of MC
monitor item by using
Dr. ZX is 3.78±0.5 V
with lift arm at the
highest position. Then,
tighten link bolt.
Connector (Harness end of connector viewed from the
open end side)
Lift Arm Auto Leveler
Switch Connector
#2
MC
Connector B
Lift Arm Angle Sensor
Connector
MC
Connector D
Lift Arm Solenoid
Valve Connector
#B3
#1
1
2
3
4
1
2
#2
3
1
#1
#B20
T183-05-04-021
T5-6-54
#2
#3
#10
T183-05-04-009
2
TROUBLESHOOTING / Troubleshooting B
A
Disconnect abnormal connector in lift
arm auto leveler
switch.
Ground terminal #2
of harness end of
connector.
Check if lift arm auto
leveler is operated
properly.
Faulty lift arm auto
leveler switch.
YES
NO
Connect terminal #2 of
harness end of connector in lift arm auto
leveler switch to vehicle frame.
Disconnect connector
MC-B in MC.
Connect terminal #B20
(upward) or B3 (downward) of harness end
to vehicle frame.
Check for continuity.
NO
YES
Open circuit in harness between lift arm
auto leveler switch
and MC.
To C
· Key switch: OFF
B
Check if voltage between terminals #1
and #3 of harness
end of connector in
lift arm angle sensor
is 5±0.5 V.
Disconnect connector
MC-D in MC.
Check for continuity
YES between terminal
#D10 of harness end
of connector and terminal #2 of harness
end of connector in lift
arm angle sensor.
NO
C
YES
YES
· Key switch: ON
Disconnect abnormal connector in lift
arm solenoid valve
in pilot valve. Check
if voltage at terminal
#1 of harness end of
connector is 24 V.
NO
Check if voltage between terminal #1 of
harness end of connector in lift arm angle
sensor and vehicle
frame is 5±0.5 V.
· Key switch: ON
NO
Connect connector in
lift arm solenoid valve
in pilot valve.
YES Connect terminal #2 of
connector to vehicle
frame.
Turn lift arm raise lever
to detent position.
Check if lever is held.
YES
NO
Open circuit in harness between MC
and lift arm angle
sensor.
To C
Open circuit in harness between MC
and lift arm angle
sensor (terminal #3).
Open circuit in harness between MC
and lift arm angle
sensor (terminal #1).
Open circuit in harness between lift arm
electromagnet and
MC, or faulty MC.
Faulty lift arm electromagnet.
Faulty fuse or faulty
harness between
fuse box B and lift
arm solenoid valve.
· Engine: Running
NO
T5-6-55
TROUBLESHOOTING / Troubleshooting B
F-12 Lift arm auto leveler stop position cannot
be set. (Optional)
• If the lift arm auto leveler stop position cannot be
set as for both upward and downward, lift arm
angle sensor learning has not been completed or
lift arm angle sensor, MC or harness may malfunction.
• If the lift arm auto leveler stop position cannot be
set as for either upward or downward, lift arm
auto leveler set switch, MC or harness may malfunction.
• Refer to “F-11 Lift arm auto leveler is not operated” and execute the remedy.
T5-6-56
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-57
TROUBLESHOOTING / Troubleshooting B
F-13 Ride control is not effective.
• Check the wiring connections first.
• When there is trouble with main circuit system
and system pilot oil in the lift arm cylinder, this
trouble may occur. As the front attachment operation malfunction together, refer to the related
pages and execute the remedy.
Ground terminal #7 of
harness end of connector in ride control
switch to vehicle frame.
YES Disconnect connector
MC-C.
Ground terminal #C21
to vehicle frame. Check
for continuity.
Disconnect connector
in ride control switch.
YES Check for continuity
between terminals #6
and #7 of switch end.
YES
Faulty MC.
NO
Open circuit in harness between ride
control switch and
· Key switch: OFF
· Ride control switch: ON
Monitor ride control
switch of MC monitor
item on Dr. ZX.
If ride control switch is
turned ON/OFF,
check if monitor display is shifted.
Faulty ride control
switch.
NO
YES
YES
· Key switch: ON
NO
Monitor travel speed of
MC monitor item on
Dr. ZX.
Check if travel speed is
7 km/h or faster.
· Travel: Forward
Normal.
When travel speed is 7
km/h at former selection, check if ride control is effective.
· Ride control switch: ON
To B
NO
To A
NO
Connector (Harness end of connector viewed from the
open end side)
Ride Control Switch Connector
Connector MC-C
Connector MC-A
C10
C1
4
1
10
5
#A23
C23
#7
#6
#A7
C31
#C21
T183-05-04-008
T5-6-58
TROUBLESHOOTING / Troubleshooting B
YES
Monitor transmission output speed of
TCU monitor item
on Dr. ZX.
Check if 880 min–1
is displayed on of
Dr. ZX screen when
traveling at 10 km/h.
A
Faulty TCU.
YES
NO
Faulty travel speed
sensor.
If travel speed increases or decreases
at former section, display on Dr. ZX is
shifted.
Faulty travel speed
sensor, or faulty
harness between
travel speed sensor
and MC.
NO
NO
Check if ride control
accumulator gas
pressure is 3 MPa
(31 kgf/cm2).
B
Replace ride control
proportional solenoid
YES valve with normal one.
Check if ride control is
operated properly.
· Between terminals
#A23 (#A7) of connector MC-A in MC and #1
(#2) in ride control
proportional solenoid
valve
YES
Proportional Solenoid
Valve Connector
#1
2
YES Faulty ride control
valve.
NO
Faulty harness between MC and ride
control proportional
solenoid valve.
Faulty ride control
proportional solenoid
valve.
Replace ride control
accumulator.
NO
#2
Check for continuity in
harness between MC
and ride control proportional solenoid
valve.
1
T5-6-59
TROUBLESHOOTING / Troubleshooting B
TRAVEL SYSTEM TROUBLESHOOTING
T-1 Machine does not travel forward/ reverse.
• Machine can travel only when the following con-
• Check the wiring connections first.
• If the followings are normal, the transmission and
ditions are present.
Forward/Reverse Lever: F or R
Parking Brake Switch: OFF
axles (front, rear) may be faulty. Check for abnormal sound at each part.
• If the front attachment operation is normal, the
engine system and the pilot oil supply system
may be normal.
NO
· Engine: Running
· Refer to the Operational Performance
Test section.
Operate brake pedal.
NO Check if brake pedal is
operated heavily with
work brake applied.
· Engine: Running
Check if trouble occurs;
although machine
YES cannot travel by using
forward/reverse switch,
machine can travel by
using forward/reverse
lever.
Monitor pedal brake
pressure of MC monitor
item on Dr. ZX. Check if
pressure is 0 MPa.
Check if front speed is
within specification.
Faulty service brake.
YES
YES
Faulty forward/reverse
switch or forward/reverse
lever, or faulty harness.
YES
Faulty brake valve.
· Engine: Running
Check if port pressure at
brake pedal outlet or
NO brake pressure inlet in
axle exists.
· Engine; Running
· Tow the machine to level
ground and execute this
item. (Refer to the opera- NO
tional manual.)
T5-6-60
Faulty service brake
pressure sensor or
shorted circuit in harness
between MC and brake
pressure sensor.
To A
TROUBLESHOOTING / Troubleshooting B
Monitor parking brake
pressure of MC moniYES tor item on Dr. ZX.
Check if pressure is
2.5 MPa (26 kgf/cm2)
or more.
· Engine: Running
· Parking brake switch:
OFF
Check if parking brake
YES solenoid valve output
pressure is 2.5 MPa
(26 kgf/cm2) or more.
NO
Open circuit in harness in MC or between MC and monitor unit.
· Between terminal
#B25 of connector
MC-B in MC and
terminal #A17 of
monitor unit connector 1-A in the monitor
unit
Faulty parking brake
pressure sensor.
Faulty forward/reverse lever or
open circuit in harness.
YES
Monitor parking
brake signal output
of monitor unit monitor item on Dr. ZX.
Check if ON is displayed by using outline characters on a
colored background.
· Engine: Running
· Parking brake switch:
OFF
NO
NO
To B
Faulty pilot system
(Refer to the reference pages on Front
Attachment System
Troubleshooting in
this group.) or faulty
engine system (Refer
to Engine Troubleshooting Manual.).
NO
B
· Engine: Running
· Parking brake switch:
OFF
YES
Faulty parking brake
system. (Refer to the
reference pages on
Brake System Troubleshooting in this
group.)
· Engine: Running
· Parking brake switch:
OFF
A
Monitor parking brake
pressure switch of
monitor unit monitor
YES item on Dr. ZX.
Check if pressure is
displayed by using
outline characters on
a colored background.
Faulty monitor unit.
NO
T5-6-61
TROUBLESHOOTING / Troubleshooting B
T-2 Machine does not travel forward or reverse.
• The transmission and axles (front, rear) may be
faulty. Check for abnormal sound at each part.
• If other operations of front attachment and swing
are normal, the pilot pump, pilot filter and pilot relief valve may be normal.
• Check the wiring connections first.
YES
Monitor selected travel
speed gear of MC
monitor item on Dr. ZX.
Operate forward/reverse lever and
travel speed gear
switch.
Check if travel speed
gear according to combination of switch operations is displayed.
· Engine: Running
· Parking brake switch:
OFF
Monitor actual travel
speed gear of MC monitor
item on Dr. ZX.
Operate forward/reverse
YES lever and travel speed
gear switch.
Check if travel speed gear
according to combination
of switch operations is
displayed.
· Engine: Running
· Parking brake switch:
OFF
Replace transmission
control valve with norYES mal one.
Check if machine operation becomes normal.
Faulty transmission control valve.
Faulty transmission.
NO
Faulty MC.
NO
YES
Check if machine can
travel forward/reverse by
NO using travel forward
lever.
· Engine: Running
NO
T5-6-62
Faulty forward/reverse
switch or open circuit in
harness.
Faulty forward/reverse
lever or open circuit in
harness.
TROUBLESHOOTING / Troubleshooting B
T-3 Machine moves with lever in neutral.
YES
Monitor selected travel
speed gear of MC
YES monitor item on Dr.
ZX.
Check if item except N
is displayed.
NO
· Travel: Forward
· Forward/reverse lever:
Neutral
Turn forward/reverse
switch ON.
Check if machine
moves.
· Travel: Forward
Monitor actual travel
speed gear of MC
monitor item on Dr.
ZX.
Check if item except N
is displayed.
Faulty forward/reverse
lever.
Faulty MC.
NO
YES
Replace transmission
control valve with norNO mal one. Check if machine operation becomes normal.
Faulty transmission control valve.
Faulty transmission.
NO
Faulty MC.
YES
T5-6-63
TROUBLESHOOTING / Troubleshooting B
T-4 Even if travel speed is turned up or down,
travel speed gear is not changed.
• If the travel speed sensor malfunctions or if two
• Check the wiring connections first.
• Refer to T2-1-28 to 31 in the Control System
wirings in the shift switch are opened, travel
speed is fixed to second gear. When the travel
speed sensor malfunctions, the fault code is displayed on MC.
group/ SYSTEM section.
NO
Execute troubleshooting of each controller
by using Dr. ZX.
Check if any fault
codes are displayed.
Monitor travel speed
gear SW of MC monitor item on Dr. ZX.
Operate shift switch
from first gear to fourth
gear.
Check if travel speed
gear is displayed on
screen according to
switch operation.
· Key switch: ON
YES
Refer to Troubleshooting
A.
YES
Disconnect connector
in shift switch.
Check if voltage at
NO terminal #7 of harness
end of connector is 24
V.
· Key switch: ON
· Engine: Running
NO
Faulty fuse or open circuit
in harness.
Refer to Troubleshooting
A.
YES
Connector MC-B
Connector (Harness end of connector viewed from the
open end side)
Shift Switch Connector
1
2
3
4
5
6
7
8
#B14
#B5
T183-05-04-021
#7
T5-6-64
TROUBLESHOOTING / Troubleshooting B
Connect connector in
shift switch.
Set travel speed to
fourth gear.
Disconnect connector
MC-B in MC.
Check for continuity
between terminals #B5
and #B14 of harness
end of connector.
· Key switch: OFF
YES
Faulty MC.
NO
Faulty shift switch or open
circuit in harness.
T5-6-65
TROUBLESHOOTING / Troubleshooting B
T-5 Even if up-shift switch is pushed, travel
speed gear is not turned up.
• Refer to T2-1-34 to 35 in the Control System
group/ SYSTEM section.
• Travel speed gear cannot be turned up by the
switch is selected, if the hold switch is pushed,
up-shift control is not operated.
up-shift switch beyond travel speed gear selected
by the shift switch.
• Check the wiring connections first.
• When auto L, N or H in the travel mode selector
YES
Monitor USS switch of
MC monitor item on Dr.
ZX.
Turn up-shift switch
ON.
Check if ON is displayed on screen.
NO
· Key switch: ON
Execute troubleshooting of each controller
by using Dr. ZX.
Check if any fault
codes are displayed.
· Engine: Running
Refer to Troubleshooting
A.
YES
Disconnect connector
in up-shift/down-shift
switch.
Check if voltage at
NO terminal #2 of harness
end of connector is 24
V.
· Key switch: ON
NO
Faulty fuse or open circuit
in harness.
Refer to Troubleshooting
A.
YES
Connector (Harness end of connector viewed from the
open end side)
Connector MC-B
Up-Shift/Down-Shift
Switch Connector
1
2
3
#2
T183-05-04-021
T5-6-66
TROUBLESHOOTING / Troubleshooting B
Connect connector in
up-shift/down-shift
switch.
Disconnect connector
in MC-B in MC.
Turn up-shift switch
ON.
Check for continuity
between terminal #B2
of harness end of connector and vehicle
frame.
YES
Faulty MC.
NO
Faulty up-shift/down-shift
switch or open circuit in
harness.
· Key switch: OFF
T5-6-67
TROUBLESHOOTING / Troubleshooting B
T-6 Even if down-shift switch is pushed, travel
speed gear is not turned down.
• Refer to T2-1-32 to 33 in the Control System
• When auto L, N or H in the travel mode selector
group/ SYSTEM section.
• When machine travels at faster than travel speed
gear, which can decrease, although the
down-shift switch is pushed, travel speed gear
cannot be turned down.
switch is selected, if the hold switch is pushed,
down-shift control is not operated.
• Check the wiring connections first.
YES
NO
Monitor DSS switch of
MC monitor item on
Dr.ZX.
Turn down-shift switch
ON.
Check if ON is displayed on screen.
· Key switch: ON
Execute troubleshooting of each controller
by using Dr. ZX.
Check if any fault
codes are displayed.
· Key switch: ON
Refer to Troubleshooting
A.
YES
Disconnect connector
in up-shift/down-shift
switch.
Check if voltage at
NO terminal #2 or #1 of
each harness end of
connector is 24 V.
· Key switch: ON
NO
Faulty fuse or open circuit
in harness.
Refer to Troubleshooting
A.
YES
Connector (Harness end of connector viewed from the
open end side)
Up-Shift/Down-Shift
Switch Connector
1
2
3
#2
Connector MC-B
Down-Shift Connector
1
2
#1
#B9
T183-05-04-021
T5-6-68
TROUBLESHOOTING / Troubleshooting B
Connect connector in
up-shift/down-shift
switch.
Disconnect connector
in MC-B in MC.
Turn down-shift side in
up-shift/down-shift
switch and down-shift
switch ON alternately.
Check for continuity
between terminal #B9
of harness end of connector and vehicle
frame.
YES
Faulty MC.
NO
Faulty switch without continuity or open circuit in
harness.
· Key switch: OFF
T5-6-69
TROUBLESHOOTING / Troubleshooting B
T-7 Even if hold switch is pushed, travel speed
gear is not fixed.
• Refer to T2-1-38 to 39 in the Control System
• Check the wiring connections first.
group/ SYSTEM section.
• When auto L, N or H in the travel mode selector
switch is selected, hold control is not operated.
YES
NO
Execute troubleshooting of each controller
by using Dr. ZX.
Check if any fault
codes are displayed.
Monitor hold switch of
MC monitor item on
Dr.ZX.
Turn hold switch ON.
Check if ON is displayed on screen.
· Key switch: ON
Refer to Troubleshooting
A.
YES
Disconnect connector
in hold switch.
Check if voltage at
NO terminal #1 of harness
end of connector is 24
V.
· Engine: Running
· Key switch: ON
NO
Faulty fuse or open circuit
in harness.
Refer to Troubleshooting
A.
YES
Connector (Harness end of connector viewed from the
open end side)
Connector MC-B
Hold Switch Connector
1
2
#1
#B4
T183-05-04-021
T5-6-70
TROUBLESHOOTING / Troubleshooting B
Connect connector in
hold switch.
Disconnect connector
MC-B in MC.
Turn hold switch ON.
Check for continuity
between terminal #B4
of harness end of connector and vehicle
frame.
YES
Faulty MC.
NO
Faulty hold switch or open
circuit in harness.
· Key switch: OFF
T5-6-71
TROUBLESHOOTING / Troubleshooting B
T-8 Travel mode is not shifted.
• Check the wiring connections first.
• Refer to T2-1-30 to 31 in the Control System
group/ SYSTEM section.
NO
Execute troubleshooting of each controller
by using Dr. ZX.
Check if any fault
codes are displayed.
Monitor auto gear shifting mode of MC monitor item on Dr. ZX.
Shift travel mode selector switch to auto L,
N and H in this order.
Check if Ld&Cry, Normal and Power are displayed on screen in this
order.
· Key switch: ON
· Engine: Running
YES
Refer to Troubleshooting
A.
Disconnect connector
in travel mode selector
switch.
Check if voltages at
terminals #2, #3, #4
NO and #5 of harness end
of connector are 1V,
2V, 3V and 4V respectively.
YES
Normal.
NO
· Key switch: ON
Refer to Troubleshooting
A.
YES
Connector (Harness end of connector viewed from the
open end side)
Travel Mode Selector
Switch Connector
#2
#4
1
2
3
4
5
6
Monitor Unit Connector 1-B
#3
#B28
#5
#B31 #B30
#B29
T4GB-05-05-002
T5-6-72
TROUBLESHOOTING / Troubleshooting B
Connect connector in
travel mode selector
switch.
Disconnect monitor
unit connector 1-B in
monitor unit.
Check if voltages at
terminals #B28, #B29,
#B30 and #B31 of
harness end of connector are 4V, 3V, 2V
and 1V respectively.
Faulty travel mode selector switch or faulty harness.
YES
· As for the harness in travel
mode selector switch, the
harness which correct current does not flow through
is faulty.
Faulty monitor unit.
NO
· Key switch: ON
T5-6-73
TROUBLESHOOTING / Troubleshooting B
T-9 Clutch cut-off is not operated.
• Check the wiring connections first.
• Refer to T2-1-36 to 37 in the Control System
group/ SYSTEM section.
NO
Monitor clutch cut-off
mode of MC monitor
item on Dr. ZX.
Shift clutch cut-off position switch to S, N and
D in this order.
Check if Low, Medium
and High are displayed
on screen in this order.
· Key switch: ON
Execute troubleshooting
of each controller by
using Dr. ZX. Check if
any fault codes are dis· Engine: Running
YES
Refer to Troubleshooting
A.
Disconnect connector
in clutch cut-off position
switch.
Check if voltages at
terminals #2, #3, #4
NO and #5 of harness end
of connector are 1V,
2V, 3V and 4V respectively.
YES
Normal.
NO
· Key switch: ON
Refer to Troubleshooting
A.
YES
Connector (Harness end of connector viewed from the
open end side)
Clutch Cut-Off Position
Switch Connector
#2
#4
1
2
3
4
5
6
Monitor Unit Connector 1-B
#3
#B28
#5
#B31 #B30
#B29
T4GB-05-05-002
T5-6-74
TROUBLESHOOTING / Troubleshooting B
Connect connector in
clutch cut-off position
switch.
Disconnect monitor
unit connector 1-B in
monitor unit.
Check if voltages at
terminals #B28, #B29,
#B30 and #B31 of
harness end of connector are 4V, 3V, 2V
and 1V respectively.
Faulty clutch cut-off position switch or faulty harness.
YES
· As for the harness in
clutch cut-off position
switch, the harness which
correct current does not
flow through is faulty.
Faulty monitor unit.
NO
· Key switch: ON
T5-6-75
TROUBLESHOOTING / Troubleshooting B
BRAKE SYSTEM TROUBLESHOOTING
B-1 Parking brake is not released.
• Check the wiring connections first.
NO
To A
Replace parking brake
relays 1, 2 with other
YES
general relays.
Check if parking brake
is operated properly.
NO
Faulty parking brake reYES lay 1 or 2.
· Engine: Running
Check if primary pilot
pressure is within
specification.
· Engine: Running
· Refer to Operational Performance Test section.
NO
Check parking brake is
actually operated.
· Engine: Running
· Forward/reverse lever:
Neutral
· Tow the machine slowly
and the parking brake
ON/OFF on order to
check.
Refer to F-1 and F-2 of
Front Attachment Troubleshooting in this group.
Replace parking brake
pressure sensor with
normal one.
Check if parking brake
YES indicator goes off (brake
is released).
NO
Refer to Troubleshooting
C.
· Engine: Running
End.
YES
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit Connector A
Parking Brake Relay 1
Connector
#A2
Parking Brake Relay 2
Connector
#2
#1
#3
#3
T183-05-04-013
#18
T183-05-04-003
T5-6-76
T183-05-04-003
TROUBLESHOOTING / Troubleshooting B
A
Remove parking
brake relay 1.
Check if voltages between terminals #1,
#3 of harness end
and vehicle frame are
24 V.
Install parking brake
relay 1.
Disconnect monitor
connector 2-A in
YES
monitor unit.
Check if voltage at
terminal #2 of harness
end of connector is 24
V.
Disconnect connector
in parking brake
switch.
Measure current at
YES connector of switch
end.
Check if all questions
are Yes.
· Discontinuity between
terminals #6 and #7 with
switch in neutral
· Discontinuity between
terminals #6 and #7 with
switch OFF
· Continuity between terminals #3 and #8 with
switch OFF
· Engine: Running
YES
NO
To B
Faulty parking brake
switch.
Faulty alternator or
faulty harness.
NO
· Key switch: ON
Faulty fuse or faulty
harness.
NO
NO
NO
B
Check for continuity
between terminal #18
of harness end of
monitor connector 2-B
and vehicle frame.
Connect monitor connector 2-A.
Check for continuity
between terminal #7 of
harness end of parking
brake switch and vehicle frame.
· Engine: Running
To C
Open circuit in harness between termiYES nal #2 and ground.
Faulty monitor unit.
YES
Shorted circuit in
harness between
terminal #7 of parking
brake switch connector, terminal #18 of
monitor connector 2-A
and terminal #2 of
parking brake relay
connector.
· Key switch: OFF
YES
Parking Brake Switch Connector
#3
4
1
10
5
#8 #7
Disconnect parking
brake relay 2.
NO Check for continuity
between terminal #2 of
harness end and vehicle frame.
#6
T5-6-77
TROUBLESHOOTING / Troubleshooting B
C
Check if voltages at
terminal #3 of harness
end of parking brake
relay 2 and vehicle
frame, at terminal #8
of parking brake
switch and vehicle
frame are 24 V respectively.
Install all electric parts,
which are removed.
Remove parking brake
YES
solenoid valve.
Check for continuity at
terminal #2 of harness
end.
Hold parking brake
switch in OFF position.
Check if voltage at
YES terminals #1 and #2 of
harness end of parking
brake solenoid valve is
24 V.
· Engine: Running
· Key switch: OFF
NO
NO
D
Keep hand away from
parking brake switch.
Check if voltage at
terminals #1 and #2 of
harness end of connector in parking
brake solenoid valve
is 24 V.
Open circuit in harness between terminal #2 and ground.
End.
NO
Faulty parking brake
solenoid valve.
Disassemble, clean
and adjust parking
brake.
Check if parking brake
becomes normal.
Open circuit in harness between terminals #1 and #5 of
parking brake relay
2.
NO
Connector (Harness end of connector viewed from the
open end side)
Parking Brake Solenoid Valve Connector
#2
1
Open circuit in harness between terminal #1 of parking
brake relay 2 and
terminal #3 of parking brake switch.
YES
· Engine: Running
#1
NO
To D
Open circuit in harness between terminal #8 of parking
brake switch or terminal #3 of parking
brake relay 2 and
terminal #4 of parking brake relay 1.
· Engine: Running
YES
YES
2
T5-6-78
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-79
TROUBLESHOOTING / Troubleshooting B
B-2 Parking brake is not locked.
• Check the wiring connections first.
NO
Replace parking brake
relay 2 with other general
YES relay.
Check if parking brake is
operated properly.
· Engine: Running
· Parking brake switch: ON
Monitor parking brake
pressure of MC monitor item on Dr. ZX.
Check if pressure is
within specification.
Disconnect connector in
parking brake switch.
Turn parking brake
switch ON.
Check for continuity
between terminals #7
and #6 of switch end.
NO
Faulty parking brake
switch.
Faulty parking brake relay 2.
YES
YES End.
Replace parking brake
pressure sensor with
YES normal one.
Check if parking brake
indicator lights.
· Engine: Running
· Parking brake switch: ON
· Refer to Operational Performance Test section.
NO
· Engine: Running
Check if parking brake
indicator does not light.
Connector (Harness end of connector viewed from the
open end side)
Parking Brake Switch Connector
Parking Brake Solenoid Valve Connector
#1
4
1
10
5
#2
1
2
#6
T5-6-80
Refer to Troubleshooting
NO C.
Stuck piston in parking
brake.
NO
#7
YES
TROUBLESHOOTING / Troubleshooting B
Disconnect connector in
parking brake solenoid
valve.
Check if voltage between
terminals #1 and #2 of
harness end is 24 V.
· Engine: Running
· Parking brake switch: ON
YES
Shorted power circuit.
NO
Stuck spool in parking
brake solenoid valve.
T5-6-81
TROUBLESHOOTING / Troubleshooting B
B-3 Service brake efficiency is bad or low.
NO
NO
Check if pressures at
ports BR1 and BR2 in
brake valve are within
specification.
· Engine: Running
· Brake pedal: Fully depressed
· Specification: 4.18 ± 0.85
2
YES
MPa (43 ± 9 kgf/cm )
Monitor service brake
pressure of monitor
unit monitor item on Dr.
ZX. Check if pressure
is within specification.
· Engine: Running
· Specification: 11.8 to
14.7 MPa (120 to 150
2
kgf/cm )
Disassemble, clean and
NO adjust pilot relief valve.
Check if brake is operated properly.
· Refer to the Operational
Performance Test section. YES
YES
Faulty pilot pump.
End.
Faulty brake valve or
faulty brake pedal.
Faulty service brake.
T5-6-82
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-83
TROUBLESHOOTING / Troubleshooting B
STEERING SYSTEM TROUBLESHOOTING
H-1 Steering cylinder operation is slow or does
not move.
• Check if the steering shaft is deformed or stuck.
NO
Remove hoses from
ports Pa and Pb in
YES
steering valve.
Check if steering wheel
is operated properly.
· Engine: Running
· Put oil into hydraulic oil
pan from hose.
Install hoses to ports Pa
and Pb in steering
valve.
Remove hoses from
port A in right and left
stop valve.
Remove hoses from
port A in right and left
stop valves.
Check if steering wheel
is operated properly.
YES
NO
To A
Stuck spool in stop
valve.
· Engine: Running
· Put oil into hydraulic oil
pan from hose.
Clogging in steering
valve pilot circuit.
YES
Check if steering handle
is operated to right and
left properly.
· Engine: Running
YES
To B
Check if front attachYES ment operating speed is
within specification.
· Engine: Running
· Refer to the Operational
Performance Test section.
NO
Monitor pump pressure
of MC monitor item on
Dr. ZX.
Check if steering relief
pressure is within
specification.
NO
· Engine: Running
· Refer to the Operational
Performance Test section.
NO
T5-6-84
To C
Faulty steering relief
valve or faulty steering
overload relief valve.
TROUBLESHOOTING / Troubleshooting B
YES
A
Install hose to port A in
stop valve. Check if
pressure at port P in
steering pilot valve is 3.7
+0.5
+5
-0.3 KPa (38 -3
kgf/cm2).
Faulty steering pilot
valve.
YES
· Engine: Running
NO
Disassemble, clean
and adjust pilot relief
valve.
Check if steering handle is operated properly.
NO
YES
B
Disassemble, clean and
adjust priority valve
(main pump).
Check if valve is operated properly.
Stuck check valve or
priority valve in charging
block, or clogged pilot
pump or pilot filter.
End.
YES
NO
End.
Disassemble, clean
and adjust steering
valve.
Check if valve is operated properly.
End.
Faulty steering cylinder.
NO
YES
C
End.
Disassemble, clean and
adjust main pump regulator.
Check if regulator is operated properly.
Faulty main pump.
NO
T5-6-85
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-86
TROUBLESHOOTING / Troubleshooting B
OTHER SYSTEM TROUBLESHOOTING
O-1 Air conditioner malfunction
The air conditioner has a self-diagnosis function.
The self-diagnosis functions to:
1) Display Fault Codes
2) Change Displayed Fault Codes
3) Delete Fault Code
4) End Fault Code Display
• Display Fault Code
1. Push the fan OFF switch and turn the fan OFF.
2. Push and hold both upper and lower sides of the
temperature control switch on the air conditioner
control panel at the same time for more than 3
seconds with the key switch ON.
NOTE: After operation has been performed, the
buzzer will sound.
Temperature
Control Switch
Fan OFF Switch
3. If any fault codes are found, the LCD displays the
fault codes as E{{.
NOTE: If more than one fault code is found, the
lower number fault code will be displayed
first.
LCD
M178-01-017
Fault Code List
Location in Trouble
Abnormal circulation
air sensor
Fault
Code
E11
E12
Abnormal fresh air
sensor
E13
E14
Abnormal coolant
temperature sensor
E15
E16
Abnormal air vent
sensor
E21
E22
Abnormal damper
E43
E44
E51
Abnormal refrigerant
Cause
Open circuit in air circulation
sensor
Shorted circuit in air circulation
sensor
Open circuit in fresh air sensor
Shorted circuit in fresh air sensor
Open circuit in coolant temperature sensor
Shorted circuit in coolant temperature sensor
Open circuit in air vent sensor
Shorted circuit in air vent sensor
Abnormal air vent damper
Abnormal air mix damper
Abnormal high/low refrigerant
pressure
T5-6-87
Symptom
Value Y (air flow-in temperature) in response to the set-temperature is fixed.
Operation is controlled under such circumstance as no fresh air sensor is provided.
Operation is controlled under such circumstance as the water temperature is
set to 60 °C (140 °F). (Warm-up control is
not performed.)
Operation is controlled under such circumstance as air flow-in temperature 0 °C
(32 °F).
Corresponding damper servo becomes
inoperable.
The compressor clutch is disengaged.
(The compressor stops.)
TROUBLESHOOTING / Troubleshooting B
• Change Displayed Fault Code
1. When displaying more than one fault code, push
either upper or bottom side of the temperature
control switch. The following fault code is displayed.
NOTE: Each time the displayed fault code is
changed, the buzzer sounds. In case only
one fault code exists, the displayed fault
code remains unchanged.
Temperature
Control Switch
LCD
• Delete Fault Code
LCD
1. Push, and hold both the circulation air switch and
the fresh air vent switch for more than 3 seconds
at the same time and the fault code is deleted.
NOTE: After the fault code is deleted, the buzzer
sounds.
2. After the fault code has been deleted, the LCD
displays E{{.
M178-01-017
Circulation
Air Switch
Fresh Air vent
Switch
M178-01-017
Fan OFF Switch
• End Fault Code Display
1. Push the fan OFF switch, and turn the fan ON.
The self-diagnostic mode is completed.
Fan Switch
T5-6-88
M178-01-017
TROUBLESHOOTING / Troubleshooting B
∗ Please fill in all sections and return this AIR CONDITIONER TROUBLE REPORT to Hitachi Tsuchiura Works Quality Assurance Dept. after
experiencing a problem with your machine’s air conditioning system.
< Air Conditioner Trouble Report >
File No.
(1) What
Checked by:
Model
(Serial No.
)
Operation Type
Manual
Semi-Auto
Full-Auto
Delivery Date
Year
Month
(2) When
Date
Year
Month
Day
Operating Hour (
h)
Time
Morning
Daytime
Evening
Night
Frequency
Every Day
Once a Week
Once a Month
Times per
(3) Where
Job Site Address
State
County
Town
Access Road Condition
Paved
Not Paved (Gravel
Sand
Soil)
(4) How (Operating Conditions)
Weather
Fine
Cloudy
Rain
Snow
Atmospheric Temperature
Very Hot
Hot
Cold
Very Cold
Operating Conditions
Parking
Traveling
Working
Temperature Control
Paint blanks equal to red indicators. / Fill in set-temperature
when full-auto operation
A/C
ON
OFF
Air Induction
Re-Circulation
Fresh Air Circulation
Control
AUTO
ON
OFF
Not Available
Panel
Fill following items when operated in manual mode or when manual control type unit is
used.
Vent Position
Front
Front / Rear
Foot
Front / Rear and Foot
Fan
First
Second
Third
Fourth
Fifth
Sixth
(5) How (Problem Symptom)
Abnormal Compressor Operation
<Check Result>
Symptom
Not turned ON
(1) Is problem reproducible ?
Not turned OFF
Reproducible
Others
Not reproducible
Uncontrollable air temperature
(2) Pressure (To be measured at gauge maniSymptom
No cool air
fold)
No warm air
Low Pressure
Others
High Pressure
Uncontrollable air volume
(3) Which parts have been replaced ?
Symptom
Air flows in Hi mode only
1
No air flows
Small air volume
2
Others
Uncontrollable vent hole
∗ Before replacing the control amplifier, be sure
Symptom
Vent hole isn’t selected
to check that the connectors are correctly conOthers
nected while repeatedly disconnecting and reAbnormal panel indication
connecting connectors.
Faulty
Indi- Vent Hole
cator
A/C
AUTO
Fresh Air Circulation
Fan OFF
Fan (Lo •
••
Hi)
Temperature Control
Symptom
Stays OFF
Stays ON
Blinks
Others
T5-6-89
TROUBLESHOOTING / Troubleshooting B
Cooling Circuit
Refrigerant pressure
in both high and
low-pressure sides is
low.
Bubbles can be seen in sight
glass.
No bubbles are seen in sight
glass.
Piping and/or parts are stained with oil,
respond to gas detector.
No oil stain is found or gas detector
does not respond. Refrigerant has not
been refilled for longer than one season.
After cooling at fast speed continuously, cooling power is reduced. Air
flow volume remains unchanged.
Air flow volume is reduced.
Insufficient
Cooling
Power
Refrigerant pressure
in low-pressure side
is high.
Bubbles can be seen in sight
glass.
Compressor cylinder is extremely hot,
emitting a smell.
Refrigerant pressure in
high-pressure side is low.
Compressor cylinder is extremely hot,
emitting a smell.
Heater unit emits hot air.
Refrigerant pressure
in high-pressure side
is high.
Bubbles can be seen in sight
glass.
Refrigerant pressure in low-pressure
side is low.
Condenser is stained and clogged.
Even if condenser is sprayed with water, few bubbles appear. Receiver dryer temperature is low.
After cooling at fast speed continuously, cooling power is reduced. Air
flow volume is reduced.
Frost forms.
Thermistor does not cool.
Thermistor cools.
T5-6-90
TROUBLESHOOTING / Troubleshooting B
Gas leaks from pipe joints and/or parts.
Re-tighten or replace parts.
Normal leakage of refrigerant from hoses.
Refill refrigerant.
Improper adjustment (excessive restriction) of expansion
valve.
Readjust or replace expansion valve.
Clogged expansion valve.
Remove clog, or replace receiver and/or expansion
valve.
Clogged low-pressure circuit and/or evaporator.
Remove clog, or replace parts.
Frozen expansion valve or water in circuit.
After evacuation, refill refrigerant and/or replace receiver dryer.
Gas leaks from case.
Seal gaps by using vinyl tape or packing compound.
Poor contact of expansion valve temperature sensing cylinder.
Make good contact. Replace temperature sensing
stay.
Improper adjustment (excessive open) of expansion valve.
Readjust or replace.
Insufficient compressor discharge (faulty gasket and/or valve).
Replace.
Improper water stop valve wire adjustment and/or faulty stop
valve.
Check and readjust or replace.
Poor airtight fitting of outside air damper (outside air induction
type).
Repair.
Clogged high-pressure circuit before receiver dryer.
Remove clog, or replace parts.
Clean Condenser.
Excessive refrigerant.
Remove excessive refrigerant to proper level.
Air is mixed in system.
After evacuation, refill refrigerant and/or replace receiver dryer.
Incorrect thermistor location.
Correct thermistor location.
Gas leaks from case.
Seal gaps by using vinyl tape or packing compound.
Faulty thermistor (stays ON).
Disconnected thermistor cord.
Even if function and performance are normal, when
air-conditioner is kept operated for a long time with thermistor
in max. cooling position and air flow in M or L mode, frost may
form.
Instruct user on correct air-conditioner operation.
(Reset thermistor to either minimum or middle cooling
position or increase air flow.)
T5-6-91
TROUBLESHOOTING / Troubleshooting B
Cooling Circuit
Case connection.
Louver resonance.
Fan contacts case, or foreign matter enters case.
Blower fan connection.
Noise
Brush friction noise, metal and/or thrust washer contact noise.
Gas blowing sound (roaring).
Gas vibration noise (compressor discharge and/or
suction gas noise).
Expansion valve connection, whistle
sound, gas blowing sound.
Abnormal noise from expansion valve (Expansion
valve is normally functioning.).
Faulty clutch bearing, and/or idle pulley bearing.
Clutch disengaging sound.
Contact of clutch amature due to resonance, or loose
belt and/or screws.
Noisy compressor.
Compressor rotating sound.
Vibration and/or loose screws due to excessive drive
belt looseness.
Broken heater core and/or hose.
Water leak and/or splash.
Clogged case drain port and/or drain hose.
Others
Absorbed cigarette and dust smell on evaporator fins.
Abnormal smell.
T5-6-92
TROUBLESHOOTING / Troubleshooting B
Repair or replace.
Remove foreign matter. Readjust fan motor location.
Slight noise is unavoidable.
Replace if loud.
No functional problem exists.
Provide silencer if intolerable.
Replace expansion valve if whistle sound is heard. Gas flow noise can be slightly heard.
Replace.
Repair or replace clutch. Re-tighten screws.
Repair or replace.
Re-adjust drive belt.
Replace.
Clean.
Clean evaporator. When humidity is high, open door. While rotating fan at approx. 1500 min-1 in
L mode for more than 10 minutes, flush smell out by condensed water.
T5-6-93
TROUBLESHOOTING / Troubleshooting B
Compressor
Compressor does not rotate.
Clutch terminal voltage is normal 24 V.
Inoperable
cooling
system.
Clutch terminal voltage is low.
Clutch terminal voltage is 0 V.
Bubbles exist even after refrigerant is refilled.
Both high and
low side
pressures are
low.
Both compressor and
blower motor rotate.
Check for oil and refrigerant leaks from parts other than
compressor and pipe joints by using gas detector.
Check for oil and refrigerant leaks from compressor (no
leaks from parts other than compressor) by using gas
detector.
(Refer to NOTE 1,
2 on page T5-6-97.)
Stain on exterior.
Refrigerant has not been refilled for longer
than one season.
Refrigerant is discharged within 1 to 2
months after being recharged. Check for
refrigerant leaks using gas detector.
Refrigerant is kept charged for longer than
2 years.
Compressor cylinder is not hot. (Refrigerant returns to compressor in liquid form.)
High pressure side is
slightly low and low pressure side is high.
No refrigerant returns in liquid form. High pressure side is low.
Bubbles can be seen through
sight glass.
Others
High pressure side is high.
Refer to the Cooling Circuit Troubleshooting
Table on page T5-6-90.
Temperature is not cooled when compressor is
operated at fast speed continuously.
Air flow from blower is insufficient.
T5-6-94
TROUBLESHOOTING / Troubleshooting B
Seized clutch.
Replace.
Improper gap between amature and rotor (improper air gap).
Replace.
Open or shorted circuit in core cable.
Shaft does not rotate (internally locked).
Replace.
Faulty Electrical System.
Faulty Electrical System.
Oil leaks from mechanical seal, gasket, and/or charge valve.
Replace.
Oil leaks from oil plug.
Oil and refrigerant leaks from front housing, and/or cylinder block joint.
Normal leaks from hoses.
Replace.
Charge
refrigerant.
No leaks (normal).
Refer to the Cooling Circuit Troubleshooting Table on page T5-6-90.
Broken valve (See NOTE 3 on page T5-6-97.)
Replace.
Blown gasket (See NOTE 3 on page T5-6-97.)
Check and adjust
oil level.
Excessive oil.
T5-6-95
TROUBLESHOOTING / Troubleshooting B
Compressor
Compressor rotation is abnormally draggy.
Overheating
is susceptible
to occur.
Trouble other than compressor.
Noise is heard when clutch is OFF.
Abnormal
noise
Noise is heard when clutch is ON.
T5-6-96
Refer to the Cooling Circuit Troubleshooting Table on page T5-6-90.
TROUBLESHOOTING / Troubleshooting B
Broken clutch bearing due to overly tightened belt.
Replace.
Shaft does not rotate.
Replace.
Shaft rotates draggy.
Broken clutch bearing.
Replace.
Contact or slip due to poor air gap.
Faulty idle pulley bearing.
Refer to the Cooling Circuit
Troubleshooting Table on
page T5-6-90.
Saggy belt.
Loose screws.
Broken valve.
Replace.
Blown gasket.
Abnormal internal noise.
Replace.
Vibration due to saggy belt.
Refer to the Cooling Circuit
Troubleshooting Table on
page T5-6-90.
Loose screws.
NOTE:
1. Do not quickly decide that oil is leaking when a stain around the clutch and/or gasket is found. A
slight oil seepage will appear due to the seal construction. However, this oil seepage will not
cause malfunction. Accurately check whether oil is leaking or seeping only.
2. When gas detector is used in the high sensitivity range, normal gas leaks from rubber hose surface may be detected. As long as the specified rubber hoses are used, the problem should not
occur. (In case a large leaks is detected, the hose may be broken.)
3. After allowing the compressor to idle for 10 to 15 minutes, normal pressure difference between
high-pressure side and low-pressure side is 0.5 MPa (5 kgf/cm2) or less. When the clutch is
turned OFF, the pressure difference between high-pressure side and low-pressure side will disappear within about 10 seconds.
T5-6-97
TROUBLESHOOTING / Troubleshooting B
WORK AFTER REPLACING COMPONENTS
The following work is required after replacing
compressor, high pressure hose, low pressure hose,
condenser, receiver tank, liquid hose and air
conditioner unit.
The same work is required when gas leakage is found.
1. Add compressor oil
Oil amount: 160 cm3 (0.17 qt)
2. Charge air conditioner with refrigerant
• Purging
• Charge air conditioner with refrigerant
• Warm-up operation
• Inspection
T5-6-98
TROUBLESHOOTING / Troubleshooting B
CHARGE
AIR
REFRIGERANT
CONDITIONER
WITH
Necessity of Purging
Make sure to purge the air conditioner circuit with a
vacuum before charging with refrigerant (R134a)
because the following problems can arise if air or
other gases remain in the A/C circuit.
Air
1. Pressure rise in the high pressure side:
If air remains in the air conditioner circuit, this
disturbs the heat exchange between refrigerant
and air in the condenser, causing pressure to rise
in the high pressure side (compressor side).
Usually, refrigerant gas is easily liquefied,
however, air cannot be liquefied and remains as a
gas in the condenser because the temperature at
which air liquefies is extremely low. That is,
liquidation of the refrigerant gas in the condenser
decreases by the amount of air in the circuit, and
the gas pressure in the high pressure side
increases accordingly.
Pressure increases if air
remains in the air
conditioner circuit.
W115-02-10-001
2. Metal corrosion:
If air remains in the air conditioner circuit, a
chemical reaction between refrigerant and
moisture in the air takes place, and as a result,
hydrochloric acid, that corrodes metals such as
aluminum, copper and iron, is produced.
Hydrochloric acid
corrodes metals if
moisture exists.
Hydrochloric Acid
W115-02-10-002
Metal Corrosion
3. Plugging of the expansion valve by moisture:
When high pressure refrigerant gas passes
through the expansion valve, gas pressure
decreases and temperature drops. Moisture
included in high pressure refrigerant gas in the air
conditioner circuit freezes at the expansion valve
orifice, plugging refrigerant flow. Operation of the
air conditioner becomes unstable and cooling
efficiency lowers.
Ice produced at the
expansion valve disturbs
refrigerant flow, lowering
cooling efficiency.
Plugged Refrigerant
Flow
W115-02-10-003
Low Cooling
Efficiency
T5-6-99
TROUBLESHOOTING / Troubleshooting B
Purging Procedure
Gauge Manifold
IMPORTANT: Never mistake the charge hose
connections.
1. Close the high and low pressure valves on the
gauge manifold (Parts Number 4360564).
Connect the high-pressure-side charge hose and
the low-pressure-side charge hoses to the
high-pressure-side charge valve (“D” marked) and
to the low-pressure-side charge valve (“S”
marked) located on the compressor, respectively.
Connect the charge hose located on the center of
the manifold bottom to the vacuum pump (Parts
Number 4360565).
NOTE: Vacuum Pump Joint
Number 4360566).
Adapter
Low Pressure
Valve
Low Pressure
Charge Hose
High Pressure
Valve
High Pressure
Charge Hose
Center Pressure
Charge Hose
Vacuum Pump
(Parts
W115-02-10-005
Low Pressure
Side
S
Compressor
D
High Pressure
Side
T142-02-05-018
Fully Open
2. Fully open the high pressure and low pressure
valves in the gauge manifold. Perform purging for
10 minutes or more by operating the vacuum
pump.
Fully Open
In Operation
W115-02-10-005
T5-6-100
TROUBLESHOOTING / Troubleshooting B
IMPORTANT: If the pointer returns to 0, retighten
the line connections and perform
purging again.
Close
3. When the low pressure gauge reading falls below
-100 kPa (-755 mmHg), stop the vacuum pump
and close the high and low pressure valves. Wait
for approximately five minutes and confirm that
the pointer does not return to 0.
Close
In Operation
W115-02-10-005
4. With the high pressure and low pressure valves of
the gauge manifold closed, connect the charge
hose to the refrigerant container (Parts Number
4347644).
Refrigerant
Container
W115-02-10-007
5. Loosen the charge hose connection to the gauge
manifold and open the refrigerant container valve
to purge air in the charge hose with the refrigerant
pressure.
Loosen
Open
W115-02-10-007
T5-6-101
TROUBLESHOOTING / Troubleshooting B
IMPORTANT: Always stop the engine when
charging the air conditioner with
refrigerant. Do not position the
refrigerant container upside down
during charging operation. When
changing the refrigerant container
during charging operation, purge air
from the charge hose, as shown in
step 10. Charge the low pressure
side hose first.
6. Fully tighten the charge hose connection to the
gauge manifold. Open the high pressure valve
and refrigerant container valve to charge with
refrigerant (R134a).
Close the high pressure valve and refrigerant
container valve when the high pressure gauge
reading reaches 98 kPa (1 kgf/cm2, 14 psi).
NOTE: Use warm water of 40 °C (104 °F) or less to
warm the refrigerant container to aid in
charging operation.
High
Pressure
Gauge
Tighten
Open
Open
W115-02-10-007
W115-02-10-008
IMPORTANT: Use the leak tester for R134a.
7. After charging, check the line connections for gas
leaks by using leak tester (Parts Number
4360567).
T5-6-102
TROUBLESHOOTING / Troubleshooting B
8. Confirm that the high pressure and low pressure
valves in the gauge manifold and the refrigerant
container valve are closed.
Start the engine and operate the air conditioner.
Operating Conditions of the Air Conditioner:
Engine Speed : Slow Idle
Cab Window : Fully Open
Cooler Switch : ON
Airflow Volume : Maximum
Thermo Switch : Maximum
Open
IMPORTANT: Do not open the high pressure valve
in the gauge manifold.
9. Open the low pressure valve in the gauge
manifold and the refrigerant container valve to
charge with refrigerant until the bubbles seen in
the receiver tank sight glass disappear.
NOTE: The required refrigerant quantity is 1050 g
(2.31 lb).
Open
W115-02-10-007
Close
10. If the refrigerant container becomes empty during
the charging work, replace it with a new refrigerant
container as follows:
• Close the high pressure and low pressure valves
on the manifold gauge.
• Replace the empty container with a new one.
• Tighten, then slightly loosen the refrigerant
container joint.
• Slightly open the low pressure valve on the
manifold gauge.
• When the refrigerant container joint starts to leak,
immediately tighten the refrigerant container joint
and close the low pressure valve on the manifold
gauge.
11. After charging, close the low pressure valve in the
gauge manifold and the refrigerant container valve.
Stop the engine.
T5-6-103
Close
W115-02-10-007
TROUBLESHOOTING / Troubleshooting B
IMPORTANT: If the air conditioner is operated with
very low refrigerant, a bad load will
be exerted on the compressor. If the
air conditioner is overcharged with
refrigerant, cooling efficiency will
lower and abnormal high pressure
will arise in the air conditioner circuit,
causing danger.
12. Start the engine and operate the air-conditioner
again.
Observe the sight glass of the receiver tank and
check refrigerant quantity.
Operating Conditions of the Air Conditioner:
Engine Speed : Slow Idle
Cab Window : Fully Open
Cooler Switch : ON
Airflow Volume : Maximum
Thermo Switch : Maximum
Sight Glass
Receiver Tank
W115-02-10-009
NOTE: As the bubbles in the sight glass vary
depending on the ambient temperature,
check refrigerant quantity confirming the
changes in pressure .
Checking procedures: Stop the air
conditioner and wait until refrigerant returns
to the balanced pressure. Then, start the air
conditioner again.
T5-6-104
TROUBLESHOOTING / Troubleshooting B
Relation between Refrigerant Quantity and Refrigerant
Flow in Sight Glass:
Refrigerant
Quantity
Refrigerant Flow in Sight Glass
(approx. 1 min. after air conditioner
switch is turned ON)
(immediately after)
(approx. 1 mm after)
Adequate
Explanation for Refrigerant Flow in Sight Glass
Immediately after the air conditioner is turned ON, few
bubbles are seen. Then the flow becomes transparent
and shows thin milk white color.
W115-02-10-016
No bubbles are seen after the air conditioner is turned
ON.
Overcharged
W115-02-10-017
Bubbles are seen continuously after the air conditioner is turned ON.
Not Enough
W115-02-10-018
W115-02-10-019
Bubbles exist: Bubbles are seen in refrigerant flow as
both liquid refrigerant and refrigerant gas exist, being
mixed.
W115-02-10-020
Transparent: Refrigerant flow is transparent as only
liquid refrigerant exists.
115-02-10-021
Milk white:
Refrigerant flow shows thin milk white
as oil and refrigerant are separated.
CAUTION: Wait until the high-pressure-side
pressure drops to less than 980 kPa (10
kgf/cm2, 142 psi) before attempting to disconnect the high-pressure-side charge hose.
Otherwise, refrigerant and compressor oil
may spout.
13. After checking refrigerant quantity, disconnect the
low-pressure-side charge hose first. Wait for the
high-pressure-side pressure to drop to less than
980 kPa (10 kgf/cm2, 142 psi). Disconnect the
high-pressure-side charge hose.
T5-6-105
TROUBLESHOOTING / Troubleshooting B
Warm-up Operation
After charting the air conditioner, carry out warm-up
operation five minute to lubricate system with
compressor oil.
Operating Conditions of the Air Conditioner:
Engine Speed : Slow Idle
Cab Window : Fully Open
Cooler Switch : ON
Airflow Volume : Maximum
Thermo Switch : Maximum
Inspection
After warm-up operation, carry out gas leak check
and performance check.
CAUTION: Refrigerant
will
produce
poisonous material if exposed to heat of 1000
°C (1800 °F) or more. Never bring refrigerant
close to a fire.
1. Check the air conditioner for gas leaks by using a
leak tester.
• Perform
checking
under
well-ventilated
conditions.
• Thoroughly wipe off dust from the charge hose
connections of the compressor.
• Pay special attention to check the line
connections.
• If any gas leaks are found, retighten the line
connections.
2. Performance Check
Carry out performance check of the air
conditioner after checking each air conditioner
component.
• Check each component for abnormalities.
• Carry out ON-OFF check of the compressor
clutch.
• Check compressor fan belt tension.
• Check coolant level in the radiator.
• Operate the air conditioner and check the
performance.
Leak Tester
W115-02-10-013
Retighten Line
Connection
W115-02-10-014
T5-6-106
TROUBLESHOOTING / Troubleshooting B
3. The checklist before the summer season is as
follows:
• Check each air conditioner component for
abnormalities.
• Check the line connections for oil leaks.
• Check refrigerant quantity.
• Check the engine cooling circuit.
• Check V-belts for wear. Replace if necessary.
4. Off-Season Maintenance
• During off-season, operate the idler pulley and
compressor at least once a month for a short time
in order to check for any abnormal sounds.
• Do not remove the compressor belts during
off-season. Operate the compressor occasionally
at slow speed for 5 to 10 minutes with the belt
slightly loosened in order to lubricate the machine
parts.
T5-6-107
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-108
TROUBLESHOOTING / Troubleshooting B
EXCHANGE INSPECTION
Exchange inspection method is a troubleshooting
method to find the trouble location by exchanging the
suspected part / component with another part
/component having identical characteristics.
Many sensors and solenoid valves used on this machine are identical. Therefore, by using this
switch-check method, faulty part /component, and/or
harness can be easily found.
(Main Pump)
Example: Abnormal pump delivery pressure sensor
high voltage (MC fault code: 11204-3)
Check Method:
1. Stop the engine. Release remained pressure
T4GB-05-06-010
in the hydraulic oil tank. (Purge the hydraulic
oil tank if possible.)
2. Replace two pressure sensors as illustrated.
CAUTION: If the sensors are removed, hydraulic oil may gush out. Take a good care
and use the oil pan.
(Charging Block)
3. Start the engine. Retry troubleshooting.
Result:
In case abnormal parking brake pressure sensor high
voltage is displayed (MC fault code 11313-3), the
pressure sensor is considered to be faulty.
T4GB-01-02-013
In case abnormal pump delivery pressure sensor high
voltage is displayed (MC fault code 11204-3), the
pump delivery pressure sensor harness is considered
to be faulty.
T5-6-109
TROUBLESHOOTING / Troubleshooting B
Applicability of Switch-Check Method
Fault Code
Trouble
11204-3
Abnormal Pump Delivery Pressure Sensor High Voltage
11204-4
Abnormal Pump Delivery Pressure Sensor Low Voltage
11209-3
Abnormal Implement Pressure Sensor High Voltage
11209-4
Abnormal Implement Pressure Sensor Low Voltage
11313-3
Abnormal Parking Brake Pressure Sensor High Voltage
11313-4
Abnormal Parking Brake Pressure Sensor Low Voltage
13314-3
Service Brake Pressure Switch High Voltage
13314-4
Service Brake Pressure Switch High Voltage
11414-2
Abnormal Operation of Transmission Clutch First Gear
Proportional Solenoid Valve Feedback
11414-3
High Current of Transmission Clutch First Gear Proportional Solenoid Valve Feedback
11414-4
Low Current of Transmission Clutch First Gear Proportional Solenoid Valve Feedback
11415-2
Abnormal Operation of Transmission Clutch Second Gear
Proportional Solenoid Valve Feedback
11415-3
High Current of Transmission Clutch Second Gear Proportional Solenoid Valve Feedback
11415-4
Low Current of Transmission Clutch Second Gear Proportional Solenoid Valve Feedback
11416-2
Abnormal Operation of Transmission Clutch Third Gear
Proportional Solenoid Valve Feedback
11416-3
High Current of Transmission Clutch Third Gear Proportional Solenoid Valve Feedback
11416-4
Low Current of Transmission Clutch Third Gear Proportional Solenoid Valve Feedback
11417-2
Abnormal Operation of Transmission Clutch Fourth Gear
Proportional Solenoid Valve Feedback
11417-3
High Current of Transmission Clutch Fourth Gear Proportional Solenoid Valve Feedback
11417-4
Low Current of Transmission Clutch Fourth Gear Proportional Solenoid Valve Feedback
11418-2
Abnormal Operation of Transmission Clutch Forward Proportional Solenoid Valve Feedback
11418-3
High Current of Transmission Clutch Forward Proportional
Solenoid Valve Feedback
11418-4
Low Current of Transmission Clutch Forward Proportional
Solenoid Valve Feedback
11419-2
Abnormal Operation of Transmission Clutch Reverse
Proportional Solenoid Valve Feedback
11419-3
High Current of Transmission Clutch Reverse Proportional
Solenoid Valve Feedback
11419-4
Low Current of Transmission Clutch Reverse Proportional
Solenoid Valve Feedback
T5-6-110
Applicability
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
Applicable (Sensor only)
TROUBLESHOOTING / Troubleshooting B
BLEEDING AIR FROM BRAKE (AXLE)
IMPORTANT: If air is contained in the brake, brake
efficiency is low so that the serious
accident may occur. When the brake
pipe is installed/ removed or hydraulic oil is replaced, release any
pressure in the brake. Until hydraulic oil (0.5 L) comes out from each
wheel (4 places) after bubbles stops,
continue to release any pressure.
1
1
NOTE: Two or more workers should do this work
at each wheel (4 places). Air bleed plug (1)
is located near the center of front/ rear axle
upper.
1. Turn the parking brake switch in front console to
P. Start the engine. Increase service brake oil
pressure.
2. Attach clear vinyl tube (2) onto end of air bleed
plug (1). Insert other of clear vinyl tube (2) into
clear container (3) filled with hydraulic oil.
3. Depress brake pedal (4) several times. Then,
depress and hold brake pedal (4) to the stroke
end.
4. Loosen air bleed plug (1) under condition in step
3 and drain hydraulic oil and air for several seconds.
5. Tighten air bleed plug (1).
6. Drain hydraulic oil after bubbles stops in steps 3
to 5 repeatedly.
T4GB-05-04-004
1
2
3
T4GB-05-04-005
NOTE: When hydraulic oil (0.5 L) comes out, air
may be remained. In this case, repeat
steps 3 to 5.
7. Release any pressure at other 3 places in the
same procedures as steps 3 to 5.
IMPORTANT: After air bleeding work is completed
at 4 places, release any pressure at
4 places again. Release any pressure in the same procedures as
steps 3 to 5 twice and check if no
remained pressure inside.
T5-6-111
4
T4GB-05-04-006
TROUBLESHOOTING / Troubleshooting B
ONE PART OF DATA, “DAILY REPORT
DATA”, “DISTRIBUTION DATA”, “TOTAL
OPERATING HOURS” AND “ALARM” IS
NOT RECORDED
• The required signal for data may not be sent to
ICF. As each signal is used for some data, check
the corresponding signal system according to the
table below.
Daily Report Data
Data
Input Signal
1
Date
Date of daily report data (Year/ Month/ Day)
2
Fuel level
Fuel level when the engine stops at last in one day
3
Fuel used amount
Fuel used amount in one day
4
Machine hour meter
Total hours of hour meter
5
Engine operating hours
Engine operating hours in one day
6
Travel operating distance
Traveling distance in one day
7
Manual gear shifting operating hours
Manual gear shifting operating hours in one day
8
Automatic gear shifting operating hours
Automatic gear shifting operating hours in one day
9
L mode operating hours
10
N mode operating hours
11
P mode operating hours
12
Radiator coolant temperature
L mode in work mode selector switch operating hours in one
day
N mode in work mode selector switch operating hours in
one day
P mode in work mode selector switch operating hours in
one day
Highest radiator coolant temperature in one day
13
Hydraulic oil temperature
Highest hydraulic oil temperature in one day
14
Fuel temperature
Highest fuel temperature in one day
15
Torque converter oil temperature
Highest torque converter oil temperature in one day
16
Engine operating hours distribution
Engine operating hours distribution in one day
(Data is recorded only when alternator output signal is received for 10 minutes or longer.)
IMPORTANT: If the trouble occurs between each
controller and sensor, the data corresponding to this trouble is not
recorded in ICF.
Although the machine is normal
(The fault code is not displayed as
T5-6-112
for all controllers, the monitor display and the machine operation are
normal) and the required data is not
recorded in ICX, execute this inspection.
TROUBLESHOOTING / Troubleshooting B
Internal clock circuit in MC
Controller sending data
on CAN
ICF
Fuel level sensor
Monitor unit
Generated/Detected Data Position
Circuit calculating fuel used amount in ECM1
ECM
Hour meter circuit in monitor unit
Monitor unit
Alternator
• Alternator
• ECM
Travel speed sensor
MC1
M mode in travel mode selector switch
MC
• L mode in travel mode selector switch
• N mode in travel mode selector switch
• H mode in travel mode selector switch
MC
L mode in work mode selector switch
MC
N mode in work mode selector switch
MC
P mode in work mode selector switch
MC
Coolant temperature sensor
Monitor unit
Hydraulic oil temperature sensor
MC
Fuel temperature sensor
ECM1
Torque converter oil temperature sensor
Monitor unit
Alternator
• Alternator
• ECM1
*
Inspected Position
-
Communication line between monitor
unit and ICF (CAN line)
Communication line between ECM1
and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
• Wiring between alternator and ICF
• Communication line between ECM1
and ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between ECM1
and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
• Wiring between alternator and ICF
• Communication line between ECM1
and ICF (CAN line)
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
T5-6-113
TROUBLESHOOTING / Troubleshooting B
Daily Report Data
Data
Input Signal
Replace ICF
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #33, #34 of connector monitor-2 in monitor unit
3 Fuel used amount
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #18, #37 of connector in ECM1
4 Machine hour meter
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #33, #34 of connector monitor-2 in monitor unit
5 Engine operating hours
Check terminal #8 of connector ICF-C in ICF, terminal L
in alternator
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #18, #37 of connector in ECM1
6 Travel operating distance
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
7 Manual gear shifting operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
8 Automatic gear shifting operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
9 L mode operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
10 N mode operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
11 P mode operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
12 Radiator coolant temperature
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #33, #34 of connector monitor-2 in monitor unit
13 Hydraulic oil temperature
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #4, #15 of connector MC-C in MC
14 Fuel temperature
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #18, #37 of connector in ECM1
15 Torque converter oil temperature
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #33, #34 of connector monitor-2 in monitor unit
16 Engine operating hours distribution
Check terminal #8 of connector ICF-C in ICF, terminal L
in alternator
Check terminals #C5, #C11 of connector ICF-C in ICF,
terminals #18, #37 of connector in ECM1
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
1
2
Date
Fuel level
T5-6-114
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-115
TROUBLESHOOTING / Troubleshooting B
Distribution Data
Data
Input Signal
1
Fuel temperature distribution
Distribution of fuel temperature
2
Pump load distribution
Distribution of main pump delivery pressure
3
Travel load distribution
Distribution of travel torque
4
Radiator coolant temperature distribution
Distribution of coolant temperature
5
Hydraulic oil temperature distribution
Distribution of hydraulic oil temperature
6
Torque converter oil temperature distribution
Distribution of torque converter oil temperature
7
Brake pressure distribution
Distribution of secondary brake pressure
8
Radiator coolant temperature - Intake-air Distribution of temperature that intake-air temperature is
temperature distribution
taken from coolant temperature
9
Hydraulic oil temperature - Intake-air tem- Distribution of temperature that intake-air temperature is
perature distribution
taken from hydraulic oil temperature
10
Torque converter oil temperature - Intake-air Distribution of temperature that intake-air temperature is
temperature distribution
taken from torque converter oil temperature
11
Radiator coolant temperature / Intake-air Distribution of coolant temperature and intake-air temtemperature
perature
12
Hydraulic oil temperature / Intake-air tem- Distribution of hydraulic oil temperature and intake-air
perature
temperature
13
Torque converter oil temperature / Intake-air Distribution of torque converter oil temperature and intemperature
take-air temperature
14
Travel speed gear distribution during manual
gear shifting
Travel speed gear distribution during automatic gear shifting
Distribution of travel speed gear during manual gear
shifting
Distribution of travel speed gear during automatic gear
shifting
Engine load rate
Distribution of engine speed and engine torque
15
16
IMPORTANT: If the trouble occurs between each
controller and sensor, the data corresponding to this trouble is not
recorded in ICF.
Although the machine is normal
(The fault code is not displayed as
T5-6-116
for all controllers, the monitor display and the machine operation are
normal) and the required data is not
recorded in ICX, execute this inspection.
TROUBLESHOOTING / Troubleshooting B
Controller sendInspected Position
ing data on CAN
Fuel temperature sensor
ECM1
Communication line between ECM1 and ICF (CAN
line)
Pump delivery pressure sensor
MC
Communication line between MC and ICF (CAN
line)
• Torque converter input shaft sensor
MC
Communication line between MC and ICF (CAN
• Torque converter output shaft sensor
line)
Coolant temperature sensor
Monitor unit
Communication line between monitor unit and ICF
(CAN line)
Hydraulic oil temperature sensor
MC
Communication line between MC and ICF (CAN
line)
Torque converter oil temperature sensor Monitor unit
Communication line between monitor unit and ICF
(CAN line)
Service brake pressure sensor
MC
Communication line between MC and ICF (CAN
line)
• Coolant temperature sensor
• Monitor unit
Communication line between monitor unit and ICF
• Intake-air temperature sensor
• ECM1
(CAN line)
Communication line between ECM1 and ICF (CAN
line)
• Hydraulic oil temperature sensor
• MC
• Communication line between MC and ICF (CAN
• Intake-air temperature sensor
• ECM1
line)
• Communication line between ECM1 and ICF
(CAN line)
• Torque converter oil temperature sen- • Monitor unit
• Communication line between monitor unit and
sor
• ECM1
ICF (CAN line)
• Intake-air temperature sensor
• Communication line between ECM1 and ICF
(CAN line)
• Coolant temperature sensor
• Monitor unit
• Communication line between monitor unit and
ICF (CAN line)
• Intake-air temperature sensor
• ECM1
• Communication line between ECM1 and ICF
(CAN line)
• Hydraulic oil temperature sensor
• MC
• Communication line between MC and ICF (CAN
• Intake-air temperature sensor
• ECM1
line)
• Communication line between ECM1 and ICF
(CAN line)
• Torque converter oil temperature sen- • Monitor unit
• Communication line between monitor unit and
sor
• ECM1
ICF (CAN line)
• Intake-air temperature sensor
• Communication line between ECM1 and ICF
(CAN line)
• M mode in travel mode selector switch • MC
• Communication line between MC and ICF (CAN
• Shift switch
line)
• L mode in travel mode selector switch MC
Communication line between MC and ICF (CAN
• N mode in travel mode selector switch
line)
• H mode in travel mode selector switch
• Shift switch
• Engine torque curve control circuit in ECM1
Communication line between ECM1 and ICF (CAN
ECM1
line)
• Engine speed sensor
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
Generated/Detected Data Position
T5-6-117
TROUBLESHOOTING / Troubleshooting B
Distribution Data
Input Signal
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#18, #37 of connector in ECM
2
Pump load distribution
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#4, #15 of connector MC-C in MC
3
Travel load distribution
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#4, #15 of connector MC-C in MC
4
Radiator coolant temperature distri- Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
bution
#33, #34 of connector monitor-2 in monitor unit
5
Hydraulic oil temperature distribution Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#4, #15 of connector MC-C in MC
6
Brake pressure distribution
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#33, #34 of connector monitor-2 in monitor unit
7
Torque converter oil temperature dis- Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
tribution
#33, #34 of connector monitor-2 in monitor unit
8
Radiator coolant temperature – In- • Check terminal #8 of connector ICF-C in ICF, terminals #33,
take-air temperature distribution
#34 of connector monitor-2 in monitor unit
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 4 of distribution data.)
9
Hydraulic oil temperature - Intake-air • Check terminals #C5, #C11 of connector ICF-C in ICF, termitemperature distribution
nals #4, #15 of connector MC-C in MC
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 5 of distribution data.)
10 Torque converter oil temperature - • Check terminal #8 of connector ICF-C in ICF, terminals #33,
Intake-air temperature distribution
#34 of connector monitor-2 in monitor unit
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 6 of distribution data.)
11 Radiator coolant temperature / In- • Check terminal #8 of connector ICF-C in ICF, terminals #33,
take-air temperature
#34 of connector monitor-2 in monitor unit
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 4 of distribution data.)
12 Hydraulic oil temperature /Intake-air • Check terminals #C5, #C11 of connector ICF-C in ICF, termitemperature
nals #4, #15 of connector MC-C in MC
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 5 of distribution data.)
13 Torque converter oil temperature / • Check terminal #8 of connector ICF-C in ICF, terminals #33,
Intake-air temperature
#34 of connector monitor-2 in monitor unit
• Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of connector in ECM1 (As the intake-air temperature sensor is not installed for ZX310, output data is same
to item 6 of distribution data.)
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
1
Data
Fuel temperature distribution
T5-6-118
TROUBLESHOOTING / Troubleshooting B
Data
Input Signal
Travel speed gear distribution during • Check terminals #C5, #C11 of connector ICF-C in ICF, termimanual gear shifting
nals #4, #15 of connector MC-C in MC
15 Travel speed gear distribution during • Check terminals #C5, #C11 of connector ICF-C in ICF, termiautomatic gear shifting
nals #4, #15 of connector MC-C in MC
16 Engine load rate
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals
#18, #37 of connector in ECM1
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
14
T5-6-119
TROUBLESHOOTING / Troubleshooting B
Total Operating Hours Data
Data
Input Signal
1
2
Hour meter (ICF)
Hour meter (monitor unit)
Hour meter value calculated in ICF
Hour meter value calculated in monitor unit
3
Engine operating hours
Total engine operating
4
Traveling distance
Total traveling distance
5
Manual gear shifting operating hours
Total manual gear shifting operating hours
6
Automatic gear shifting operating Total automatic gear shifting operating hours
hours
7
L mode operating hours
Total L mode in work mode selector switch operating hours
8
N mode operating hours
Total N mode in work mode selector switch operating hours
9
P mode operating hours
Total P mode in work mode selector switch operating hours
IMPORTANT: If the trouble occurs between each
controller and sensor, the data corresponding to this trouble is not
recorded in ICF.
Although the machine is normal
(The fault code is not displayed as
for all controllers, the monitor display and the machine operation are
normal) and the required data is not
recorded in ICX, execute this inspection.
T5-6-120
TROUBLESHOOTING / Troubleshooting B
Generated/Detected Data Position
Hour meter circuit in ICF
Hour meter circuit in monitor unit
Controller sending data
on CAN
ICF
Monitor unit
Alternator
• Alternator
• ECM1
Travel speed sensor
MC
M mode in travel mode selector switch
MC
• L mode in travel mode selector switch
• N mode in travel mode selector switch
• H mode in travel mode selector switch
MC
L mode in work mode selector switch
MC
Inspected Position
Communication line between monitor
unit and ICF (CAN line)
• Wiring between alternator and ICF
• Communication line between ECM1
and ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
Communication line between MC and
ICF (CAN line)
N mode in work mode selector switch
MC
Communication line between MC and
ICF (CAN line)
P mode in work mode selector switch
MC
Communication line between MC and
ICF (CAN line)
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
T5-6-121
TROUBLESHOOTING / Troubleshooting B
Total Operating Hours Data
Input Signal
Replace ICF
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #33, #34 of
connector monitor-2 in monitor unit
3
Check terminal #8 of connector ICF-C in ICF, terminal L in alternator
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #18, #37 of
connector in ECM1
4 Traveling distance
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
connector MC-C in MC
5 Manual gear shifting op- Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
erating hours
connector MC-C in MC
6 Automatic gear shifting Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
operating hours
connector MC-C in MC
7 L mode operating hours
Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
connector MC-C in MC
8 N mode operating hours Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
connector MC-C in MC
9 P mode operating hours Check terminals #C5, #C11 of connector ICF-C in ICF, terminals #4, #15 of
connector MC-C in MC
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
1
2
Data
Hour meter (ICF)
Hour meter (monitor
unit)
Engine operating hours
T5-6-122
TROUBLESHOOTING / Troubleshooting B
(Blank)
T5-6-123
TROUBLESHOOTING / Troubleshooting B
Alarm Data
Data
1
2
3
4
5
6
7
8
9
10
11
12
13
Input Signal
Overheat alarm
Data when overheat indicator lights
Engine warning alarm
Data when engine warning indicator lights
Engine oil pressure alarm
Data when engine oil pressure indicator lights
Alternator indicator alarm
Data when alternator indicator lights
Air cleaner restriction alarm
Data when air cleaner restriction indicator lights
Water separator alarm
Data when water separator indicator lights
Service brake oil level alarm
Data when air cleaner restriction indicator lights
Service brake oil pressure alarm
Data when brake oil lever indicator lights
Emergency steering operation alarm
Data when emergency steering operation indicator lights
Steering oil pressure alarm
Data when steering oil pressure indicator lights
Transmission oil temperature alarm
Data when transmission oil temperature indicator lights
Hydraulic oil temperature alarm
Data when hydraulic oil temperature indicator lights
Transmission filter restriction alarm
Data when transmission filter restriction indicator lights
Transmission malfunction alarm
Data when transmission malfunction indicator lights
14
IMPORTANT: If the trouble occurs between each
controller and sensor, the data corresponding to this trouble is not
recorded in ICF.
Although the machine is normal
(The fault code is not displayed as
for all controllers, the monitor display and the machine operation are
normal) and the required data is not
recorded in ICX, execute this inspection.
T5-6-124
TROUBLESHOOTING / Troubleshooting B
Overheat switch
Controller sending data
on CAN
Monitor unit
ECM
Monitor unit
Engine oil pressure switch
Monitor unit
Alternator
Monitor unit
Air cleaner restriction switch
Monitor unit
Water separator level sensor
Monitor unit
Air cleaner restriction switch
Monitor unit
Hydraulic oil level switch
Monitor unit
Emergency steering sensor
Monitor unit
Main pump delivery pressure sensor
Monitor unit
Transmission oil temperature sensor
Monitor unit
Hydraulic oil temperature sensor
Monitor unit
• Transmission filter restriction switch
Monitor unit
• Torque converter input speed sensor
• Torque converter output speed sensor
• Transmission medium shaft sensor
• Travel speed sensor
• Forward/reverse lever
• Forward/reverse switch
• Brake pressure sensor
Monitor unit
Generated/Detected Data Position
Inspected Position
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
Communication line between monitor
unit and ICF (CAN line)
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
T5-6-125
TROUBLESHOOTING / Troubleshooting B
Alarm Data
Data
Input Signal
Check terminals #C5, #C11 of connector ICF-C in ICF,
1
terminals #33, #34 of connector monitor-2 in monitor unit
Engine warning alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
2
terminals #33, #34 of connector monitor-2 in monitor unit
Engine oil pressure alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
3
terminals #33, #34 of connector monitor-2 in monitor unit
Alternator indicator alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
4
terminals #33, #34 of connector monitor-2 in monitor unit
Air cleaner restriction alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
5
terminals #33, #34 of connector monitor-2 in monitor unit
Water separator alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
6
terminals #33, #34 of connector monitor-2 in monitor unit
Service brake oil level alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
7
terminals #33, #34 of connector monitor-2 in monitor unit
Service brake oil pressure alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
8
terminals #33, #34 of connector monitor-2 in monitor unit
Emergency steering operation alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
9
terminals #33, #34 of connector monitor-2 in monitor unit
Steering oil pressure alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
10
terminals #33, #34 of connector monitor-2 in monitor unit
Transmission oil temperature alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
11
terminals #33, #34 of connector monitor-2 in monitor unit
Hydraulic oil temperature alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
12
terminals #33, #34 of connector monitor-2 in monitor unit
Transmission filter restriction alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
13
terminals #33, #34 of connector monitor-2 in monitor unit
Transmission malfunction alarm
Check terminals #C5, #C11 of connector ICF-C in ICF,
14
terminals #33, #34 of connector monitor-2 in monitor unit
As for inspection method of the CAN line, refer to Troubleshooting A group in TROUBLESHOOTING section.
Overheat alarm
T5-6-126
TROUBLESHOOTING / Troubleshooting C
TROUBLESHOOTING C (TROUBLESHOOTING FOR MONITOR) PROCEDURE
Use troubleshooting C when any monitors, such as
gauges or indicators malfunction.
• How to Read Troubleshooting Flow Charts
YES (OK)
・
(2)
After completing the checking and/or measuring procedures in box
(1), select YES (OK) or NO (NOT OK) and proceed to box (2) or (3).
(1)
NO (NOT OK)
・
· Key switch: ON
(3)
Instructions, reference, and/or instruction methods on inspection and/or measurements
are occasionally described under the box. If incorrectly checked or measured, not only
will troubleshooting be unsuccessful but also damage to components may result.
・
Use the service mode in monitor and the diagnosing system / controller diagnosing
system in Dr. ZX.
・
Causes of machine problems are stated in the thick-line box. Scanning quickly through
the thick-line boxes, allows you to estimate the possible causes before actually following
the flow chart.
NOTE: All harness end connector are seen from
the open-end side.
Harness End
Connector
Open End Side
Harness
T6L4-05-03-001
T5-7-1
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF INDICATOR LIGHT
CHECK SYSTEM
• Check the wiring connections first.
YES
Indicator does not light when
indicator light check operation
is performed.
Check if all indicators do not
light.
NO
YES
Check power line
· Fuse
· Disconnect connector 1-A.
Check for continuity between
terminal #2 of harness end
and fuse terminal #8 in fuse
box A.
Check if trouble occurs.
Conduct troubleshooting of
each indicator, which does not
light.
Faulty fuse #8 in fuse box A, or
open circuit in harness between
fuse #8 and monitor.
A
Faulty monitor unit.
NO
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-A
＃2
T183-05-04-013
T5-7-2
To A
TROUBLESHOOTING / Troubleshooting C
(Blank)
T5-7-3
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF BUZZER IN MONITOR
• Check the wiring connections first.
YES
When engine starts,
buzzer continues to
sound.
Faulty engine oil pressure system.
Check if engine oil
pressure indicator
lights.
YES
NO
Overheated engine.
Check if overheat indicator lights.
Faulty monitor unit.
NO
Although stop indicator or brake low
oil pressure indicator lights, or high
axle oil temperature
is detected, buzzer
does not sound.
NO
Normal.
Check if engine
-1
speed is 900 min
(rpm) or faster.
NO
Check if alternator inYES dicator lights.
YES
Conduct troubleshooting
of lighted indicator.
Disconnect connector
from alternator.
Check voltage at terminal
L (terminal #2 of alternator connector) of alternator.
· Engine speed:
-1
900 min (rpm) or faster
T5-7-4
TROUBLESHOOTING / Troubleshooting C
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
＃2
Alternator Connector
＃2
T183-05-04-013
Less than 12 V
or 35 V or higher
Faulty regulator or faulty alternator.
Less than 12 V
or 35 V or higher
Check voltage at terminal #2
on connector 2-A in monitor
Between 12 V unit.
and 35 V
· Engine speed
900 min-1 (rpm) or faster
Open circuit in harness between terminal L in alternator
and monitor unit.
Faulty monitor unit.
Between 12 V
and 35 V
T5-7-5
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF
PERATURE GAUGE
COOLANT
TEM-
• Although the fault code is displayed in ECM 1 and
2 and if trouble occurs, conduct this remedy.
• Check the wiring connections first.
YES
Coolant temperature gauge
pointer does not move at all.
Disconnect connector C in ECM
1.
Connect terminal #4 of harness
end to vehicle frame.
Check if pointer swings to (H)
side.
· Key switch: ON
NO
Disconnect connector 2-A.
Check if voltage at terminal
#9 of monitor unit end
connector is 5V.
YES
Coolant temperature gauge
pointer swings over scale.
Disconnect connector C in
ECM 1.
Check if pointer returns to
zero.
· Key switch: ON
NO
Coolant temperature gauge
pointer keeps moving unstably.
Disconnect connector C in
ECM 1.
Connect terminal #4 of harness end to vehicle frame.
Check if pointer swings and is
stabilized to (H) side.
YES
· Key switch: ON
NO
T5-7-6
Disconnect connector 2-A.
Check if voltage at terminal
#9 of monitor unit end
connector is 5V.
TROUBLESHOOTING / Troubleshooting C
Coolant Temperature Gauge
Faulty ECM 1.
YES
Open circuit in harness between monitor unit and ECM
1.
Faulty monitor unit.
T4GB-05-07-005
NO
Faulty ECM 1.
YES
Open circuit in harness between monitor unit and ECM
1.
Faulty monitor unit.
NO
Coolant Temperature Sensor
Coolant Temperature
°C (°F)
25 (77)
40 (104)
50 (122)
80 (176)
95 (203)
105 (221)
120 (248)
Resistance (Ω)
447
287
200
69
44±2.5
33±2.5
23
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
#9
Faulty ECM 1.
T183-05-04-013
ECM 1
Connector C
Faulty monitor unit.
#4
T5-7-7
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF TRANSMISSION OIL
TEMPERATURE GAUGE
• Check the wiring connections first.
YES
Transmission oil temperature
gauge pointer does not move
at all.
Disconnect oil temperature
sensor.
Connect harness end terminal
to vehicle frame.
Check if pointer swings to (H)
side.
· Key switch: ON
NO
Disconnect connector 2-A
in monitor unit.
Check if voltage at terminal
#5 of monitor unit end
connector is 5V.
YES
Transmission oil temperature
gauge pointer swings over
scale.
Disconnect oil temperature
sensor.
Check if pointer returns to
zero.
· Key switch: ON
NO
YES
Transmission oil temperature
gauge pointer keeps moving
unstably.
Disconnect oil temperature
sensor.
Connect harness end terminal
to vehicle frame.
Check if pointer swings and is
stabilized to (H) side.
· Key switch: ON
T5-7-8
NO
Disconnect connector 2-A
in monitor unit.
Check if voltage at terminal
#5 of monitor unit end
connector is 5 V.
TROUBLESHOOTING / Troubleshooting C
Transmission Oil Temperature Gauge
Faulty transmission oil temperature sensor.
YES
Open circuit in harness between monitor unit and sensor.
Faulty monitor unit.
NO
T4GB-05-07-006
Transmission Oil Temperature Sensor
Oil Temperature
°C (°F)
25 (77)
40 (104)
50 (122)
80 (176)
95 (203)
105 (221)
120 (248)
Faulty transmission oil temperature sensor.
YES
Shorted circuit in harness
between monitor unit and
sensor.
Faulty monitor unit.
NO
Resistance (kΩ)
7.6±0.76
4.0±0.35
2.7±0.22
0.92±0.07
0.56±0.04
0.42±0.03
0.28±0.01
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
＃5
Faulty transmission oil temperature sensor.
T183-05-04-013
Faulty monitor unit.
T5-7-9
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF FUEL GAUGE
• Check the wiring connections first.
YES
Fuel gauge pointer does not
move at all.
Disconnect fuel sensor.
Connect terminal #1 to terminal
#2 of harness end connector by
using a clip.
Check if pointer swings to
(FULL) side.
· Key switch: ON
NO
Disconnect connector 2-A in
monitor unit.
Check if voltage at terminal #8
of monitor end connector is 5 V.
YES
Fuel gauge pointer swings over
scale.
Disconnect fuel sensor.
Check if pointer returns to zero.
· Key switch: ON
NO
YES
Fuel gauge pointer keeps moving unstably.
Disconnect fuel sensor.
Connect terminal #1 to terminal
#2 of harness end connector by
using a clip.
Check if pointer swings and is
stabilized to (FULL) side.
· Key switch: ON
T5-7-10
NO
Disconnect connector 2-A in
monitor unit.
Check if voltage at terminal #8
of monitor end connector is 5 V.
TROUBLESHOOTING / Troubleshooting C
Fuel Gauge
Upper Limit
Faulty fuel sensor.
YES
1/2
Open circuit in harness between monitor unit and sensor.
Lower Limit
Faulty monitor unit.
T4GB-05-07-007
NO
Fuel Sensor
Float
Upper Limit (FULL)
Faulty fuel sensor.
R134.5
106 mm
YES
Shorted circuit in harness
between monitor unit and
sensor.
14 mm
1/2
Faulty monitor unit.
NO
106 mm
Lower Limit (EMPTY)
T4GB-05-07-008
Faulty fuel sensor.
NOTE: 1 mm = 0.03937 in
Faulty monitor unit.
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-A
＃8
Float Position
Upper Limit (FULL)
1/2
Warning Level
Lower Limit (EMPTY)
Fuel Sensor
1
T183-05-04-013
T5-7-11
2
Resistance (Ω)
10+0-4
30±5
77±3
90+10-0
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF TURN SIGNAL INDICATORS (LEFT AND RIGHT)
• Check the wiring connections first.
• If the turn signal indicators (left and right) do not
blink, the flasher relay may be faulty.
YES
Although turn signal
lever is shifted, turn
signal light or turn
signal indicator at one
side does not blink.
When hazard light
switch is shifted,
check if all turn signal
lights or turn signal
indicators light or
blink.
Faulty turn signal lever.
YES
Replace turn signal relay
(right) (AR8) with turn signal
relay (left) (BR7).
NO Check if symptom is
switched.
NO
YES
Although turn signal
lever is not shifted,
turn signal light or turn
signal indicator blinks.
Replace turn signal
relay (right) (AR8)
with turn signal relay
(left) (BR7).
Check if symptom is
switched.
NO
T5-7-12
Faulty turn signal relay.
Burnt indicator light or open
circuit in harness between
turn signal lever and turn
signal relay.
Faulty turn signal relay.
Faulty turn signal lever or
shorted circuit in harness
between turn signal lever and
turn signal relay.
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF HAZARD LIGHT INDICATOR
• The hazard light indicator lights when the signal of
turn signal relay in left and right enters into the
hazard light switch. Therefore, although both turn
signal indicator light or blink and if the hazard light
indicator does not light, the harness between turn
signal relay and monitor unit may be faulty or the
monitor unit may be faulty. If the turn signal indicator at one side does not light or blink, refer to
troubleshooting that harness between turn signal
relay and hazard light switch may be faulty or the
turn signals (left and right) may be faulty in order
to conduct the remedy.
• Check the wiring connections first.
T5-7-13
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF HIGH BEAM INDICATOR
• Check the wiring connections first.
Although dimmer
switch is turned to
HIGH beam position,
high beam indicator
does not light.
Although dimmer
switch is not in HIGH
beam position, high
beam indicator lights.
Replace high beam relay
YES (AR3) with parking brake
relay (BR1).
Check if high beam indicator lights.
YES
NO
Check if voltage at terminals #1 and #3 in high
beam relay (AR3) is 24
V respectively.
Faulty high beam relay (AR3).
Disconnect connector of
head light switch.
Check if voltage at terminal
#2 of harness end connector is 0 V.
NO
Faulty fuse or open circuit in
harness between fuse and
high beam relay (AR3).
YES
Faulty high beam relay (AR3).
Replace high beam relay
(AR3) with parking brake
relay (BR1).
Check if high beam indicator goes out.
YES
NO
Disconnect connector
2-B in monitor unit.
Check if high beam indicator goes out.
Faulty monitor unit.
NO
T5-7-14
Connect the disconnected
connector.
Disconnect connector of
head light switch.
Check if high beam indicator
goes out.
TROUBLESHOOTING / Troubleshooting C
Open circuit in harness between high beam relay (AR3)
and head light switch.
YES
Check for continuity between terminals #2 and
NO #4 of head light switch
end connector.
Connect the disconnected connector.
YES Disconnect connector
2-B in monitor unit.
Check if voltage at terminal #22 of harness
end connector is 0 V.
Open circuit in harness between high beam relay (AR3)
and monitor unit.
YES
Faulty logic circuit in monitor
unit or burnt indicator light.
NO
Faulty head light switch.
NO
YES
Faulty head light switch.
NO
Shorted circuit in harness between high beam relay (AR3)
and head light switch.
Connector (Harness end of connector viewed from the
open end side)
Head Light Switch Connector
Monitor Unit
Connector 2-B
High Beam Relay Connector
＃2
＃22
＃1
＃3
T4GB-05-05-002
T5-7-15
＃4
T183-05-04-003
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF WORKING LIGHT INDICATOR
• Check if the working light switch and head light
switch are in the ON position.
• If the clearance light indicator also does not light,
the common circuit for clearance light indicator
and working light indicator may be faulty. Refer to
the Malfunction of Clearance Light Indicator section.
• Check the wiring connections first.
Disconnect connector 1-B
in monitor unit.
YES Check if voltage at terminal #23 of harness end
connector is 24 V.
Although working light
switch is turned to ON
position, working light
indicator does not
light.
Check if working light
lights.
Faulty working light indicator.
NO
Open circuit in harness between working light relay 1
(AR8) and monitor unit.
NO
Open circuit in harness between fuse and working light
relay 1 (AR8) or open circuit
in fuse.
YES
Replace working light relay 1
(AR8) with working light relay
2 (AR7).
Check if indicator lights.
Check if voltage at terminal #3 of working light reNO lay 1 (AR8) is 24 V.
Replace working light relay
1 (AR8) with working light
YES relay 2 (AR7).
Check if indicator goes
out.
Although working light
switch is turned to
OFF position, working
light indicator lights.
YES
YES
Faulty working light relay 1
(AR8).
NO
Check if working light
lights.
Shorted circuit in harness
between working light relay 1
(AR8) and monitor unit.
NO
T5-7-16
TROUBLESHOOTING / Troubleshooting C
YES
NO
Faulty working light relay
1 (AR8).
Check for continuity
between terminal #8
YES of working light
switch end connector
Disconnect connector
and vehicle frame.
of working light
· Working light switch:
switch.
ON
Check if voltage at
terminal #8 of harness
end connector is 24
V.
NO
Connect the disconnected
connector.
Disconnect connector 1-B in
YES monitor unit.
Check if voltage at terminal
#23 of harness end connector is 24 V.
YES Faulty working light.
Open circuit in harness
between working light
relay 1 (AR8) and moniNO tor unit.
Faulty working light
switch.
NO
Open circuit in harness
between working light
relay 1 (AR8) and working light switch.
YES
Faulty working light
switch.
Disconnect connector of
working light switch.
Check if indicator goes out.
Shorted circuit in harness between working
light relay 1 (AR8) and
working light switch.
NO
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-B
Working Light Relay
Working Light Switch Connector
＃23
＃3
T183-05-04-003
T4GB-05-05-002
＃8
T5-7-17
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF FORWARD/REVERSE
SWITCH INDICATOR
CAUTION: Turn the forward/reverse lever
and the forward/reverse switch to neutral and
turn the forward/reverse selector switch to
the ON position. If not, the indicator does not
light and the machine cannot be operated by
the forward/reverse switch.
Although forward/reverse selector
switch is turned to ON
position, indicator
does not light.
Disconnect connector 1-B
in monitor unit.
YES Check for continuity between terminal #34 of
harness end connector
and vehicle frame.
Check if the machine
can be operated by
the forward/reverse
switch.
· Forward/reverse
selector switch: ON
· Forward/reverse
selector switch: ON
Disconnect connector B in
MC.
Check if voltage at termiNO nal #13 of harness end
connector is 24 V.
YES
NO
YES
· Forward/reverse
selector switch: ON
NO
Open circuit in harness between terminal #34 of connector 1-B in monitor unit and
terminal #23 of connector B
in MC, or faulty MC.
Faulty connection of MC and
connector, or faulty MC.
Connect the disconnected
connector.
Disconnect connector of forward/reverse selector switch.
Check if voltage at terminal
#91 of harness end connector is 24 V.
Faulty forward/reverse selector switch, or shorted circuit in harness between terminals #2 and #4 of connector.
YES
Although forward/reverse selector
switch is in OFF position, indicator lights.
Faulty connection of terminals in monitor unit and connector, faulty indicator, or
faulty monitor unit.
Turn forward/reverse
lever to Forward or
Reverse.
Check if machine
moves and indicator
goes out.
YES
Disconnect connector B in
MC.
NO Check if indicator goes
out.
NO
T5-7-18
Shorted circuit in harness
between terminals of harness
end connector in MC, or
faulty MC.
Shorted circuit in harness
between terminal #23 of
connector B in MC and terminal #34 of connector 1-B in
monitor unit, or faulty monitor
unit.
TROUBLESHOOTING / Troubleshooting C
YES
Check for continuity
between terminals #2
and #7 of switch end in
forward/reverse selector switch.
· Forward/reverse
selector switch: ON
Open circuit in harness
between terminal #2 in
forward/reverse selector
switch and terminal #13
of connector B in MC.
YES
Faulty forward/reverse
selector switch.
NO
Open circuit in harness
between terminal #7 of
connector end in forward/reverse selector
switch and fuse.
NO
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-B
Forward/Reverse Selector Switch Connector
MC
Connector B
＃2
T4GB-05-05-002
＃34
＃7
＃13 ＃23
T183-05-04-021
T5-7-19
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF MAINTENANCE INDICATOR
• The maintenance indicator lights when the hour
meter reaches the set replacement interval for
lubrication system and filter. (Refer to the operation manual.) The maintenance indicator lighting
is controlled in the logic circuit of monitor unit. If
the maintenance indicator lights during the time
when the maintenance indicator must go out, the
monitor unit may be faulty. If the maintenance indicator does not light during the time when the
maintenance indicator must light, the light or the
monitor unit may be faulty.
T5-7-20
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF PREHEAT INDICATOR
• Although the fault code is displayed in ECM 1 and
2 and if trouble occurs, conduct this remedy.
• The preheat system operates only when coolant
temperature is below the specification. (Refer to
the SYSTEM / Electrical Circuit group.)
• In case the preheat system malfunctions, refer to
Troubleshooting B.
• Check the wiring connections first.
Faulty coolant
temperature sensor.
YES
Preheat indicator
lights although preheat system does
not operate
(coolant temperature is more than
specification).
Disconnect connector of coolant
temperature sensor.
Check if preheat
indicator goes out.
· Key switch: ON
YES
Disconnect connector D in ECM 1.
NO Check if preheat
indicator goes out.
· Key switch: ON
NO
Faulty ECM 1.
Check for continuity between terminal #7 of harness
end connector D in
ECM 1 and vehicle
frame.
YES
NO
Preheat indicator
does not light although preheat
system operates
(coolant temperature is lower than
specification).
· Key switch: ON
Faulty monitor
controller.
Faulty coolant
temperature sensor
YES
Disconnect connector of coolant
temperature sensor.
Short harness end
connector.
Check if indicator
lights.
Shorted circuit in
harness between
ECM 1 and monitor unit.
YES
Disconnect connector D in ECM 1.
Connect terminal
#7 of harness end
connector to vehiNO
cle frame.
Check if preheat
indicator lights.
· Key switch: ON
NO
Faulty ECM 1.
Connect terminal
#24 of connector
1-B in monitor unit
to vehicle frame.
Check if preheat
indicator lights.
YES
Open circuit in
harness between
ECM 1 and monitor controller.
Faulty monitor unit.
· Without disconnect- NO
ing connector, connect connector to
vehicle frame by
using a clip from the
rear of connector.
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-B
ECM 1
Connector D
#24
#7
T4GB-05-05-002
T5-7-21
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF TRANSMISSION OIL
TEMPERATURE
• Check the wiring connections first.
Indicator does not
light although engine
overheats.
Disconnect connector
of transmission oil
temperature sensor.
Connect terminal of
YES harness end to vehicle
frame.
Check if indicator
lights.
YES
· Key switch: ON
NO
Check if indicator
lights when key
switch is turned to
ON position.
· Key switch: ON
· Without disconnecting
connector, connect connector to vehicle frame by
using a clip from the rear
of connector.
· Key switch: ON
NO
YES
Indicator lights although oil temperature is low.
Disconnect terminal of transmission
oil temperature
sensor.
Check if indicator
goes out.
· Key switch: ON
· Engine: Stopped
Connect the disconnected terminal.
Connect terminal #5 of
connector 2-A in monitor
unit to vehicle frame.
Check if indicator lights.
YES
NO
Disconnect connector 2-A in
monitor unit.
Check if indicator
goes out.
· Key switch: ON
T5-7-22
NO
TROUBLESHOOTING / Troubleshooting C
Faulty transmission oil
temperature sensor.
YES
Open circuit in harness
between monitor unit and
transmission oil temperature sensor.
Transmission Oil Temperature Indicator
Oil Temperature
Operation
Less than 110 °C
OFF
(230 °F)
120 °C (248 °F) or
ON
higher
Faulty monitor unit.
NO
Connector (Harness end of connector viewed from the
open end side)
Faulty monitor unit, or
burnt indicator light.
Monitor Unit
Connector 2-A
#5
T183-05-04-013
Faulty transmission oil
temperature sensor.
Shorted circuit in harness
between monitor unit and
transmission oil temperature sensor.
Faulty monitor unit.
T5-7-23
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF HYDRAULIC
TEMPERATURE INDICATOR
OIL
• The hydraulic oil temperature indicator is not
turned on by the signal directly input from the
sensors. The signal data which inputs to other
controllers from the sensors once is input to the
monitor unit by using the CAN communication
and is proceeded in the logic circuit of monitor
unit.
• When this trouble occurs, refer to Troubleshooting
A and remedy the trouble on fault code.
• Although the fault code is not displayed and if the
trouble occurs after re-trial, the connection between monitor unit and terminal #33 or #34 of
connector 2-B in monitor unit may be faulty, or the
monitor unit may be faulty.
Hydraulic Oil Temperature Indicator
Oil Temperature
Operation
Less than 95 °C
OFF
(203 °F)
105 °C (221 °F) or
ON
higher
T5-7-24
TROUBLESHOOTING / Troubleshooting C
(Blank)
T5-7-25
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION
OF
WARNING INDICATOR
TRANSMISSION
• Although the fault code is not displayed in MC and
if the trouble occurs, conduct this remedy.
• Check the wiring connections first.
YES
Disconnect connector B
in MC.
YES Connect terminal #24 of
harness end connector
to vehicle frame.
Check if indicator lights.
Although transmission is abnormal,
indicator does not
light.
When key switch is
turned to ON position, check if indicator lights.
NO
· Key switch: ON
· Without disconnecting connector, connect to vehicle
frame by using a clip from
the rear of connector.
NO
YES
Although transmission is not abnormal,
indicator lights.
Disconnect connector B in MC.
Check if indicator
goes out.
· Key switch: ON
· Engine: Stopped
Connect the disconnected
connector.
Connect terminal #15 of
connector 1-A in monitor
unit to vehicle frame.
Check if indicator lights.
YES
NO
Disconnect connector
1-A in monitor unit.
Check if indicator goes
out.
NO
T5-7-26
TROUBLESHOOTING / Troubleshooting C
Faulty MC.
YES
Open circuit in harness
between monitor unit and
MC.
Faulty monitor unit.
NO
Faulty monitor unit, or
burnt indicator light.
Faulty MC.
Shorted circuit in harness
between monitor unit and
MC.
Faulty monitor unit.
Connector (Harness end of connector viewed from the
open end side)
MC
Connector B
Monitor Unit
Connector 1-A
T183-05-04-013
#15
＃24
T183-05-04-021
T5-7-27
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF AIR FILTER RESTRICTION INDICATOR
• Check the wiring connections first.
YES
Although air filter is
clogged, indicator
does not light.
Check if indicator
lights when key
switch is turned to
ON position.
Disconnect air filter restriction switch at plug
receptacle with light
YES
green cable.
Connect plug of harness
end to vehicle frame.
Check if indicator lights.
· Key switch: ON
NO
· Key switch: ON
NO
YES
Although air filter is
not clogged, indicator lights.
Disconnect plug of air
filter restriction switch.
Check if indicator goes
out.
· Disassemble and
visually inspect.
· Verify that air filter
is not moist.
· Key switch: ON
YES
NO
Disconnect connector 1-A in
monitor unit.
Check if indicator
goes out.
· Key switch: ON
T5-7-28
NO
Disconnect connector
1-A in monitor unit.
Check for continuity
between terminal #9 of
harness end connector
and air filter restriction
switch.
TROUBLESHOOTING / Troubleshooting C
Air Filter Restriction Switch Operational Resistance:
6.2±0.6 kPa (635±58 mmH2O)
Faulty air filter restriction
switch.
YES
Faulty monitor unit.
NO
Open circuit in harness
between monitor unit and
air filter restriction switch.
Connector (Harness end of connector viewed from the
open end side)
Faulty monitor unit, or
burnt indicator light.
Monitor Unit
Connector 1-A
#9
Faulty air filter restriction
switch.
Shorted circuit in harness
between monitor unit and
air filter restriction switch.
Faulty monitor unit.
T5-7-29
T183-05-04-013
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF ENGINE OIL PRESSURE INDICATOR
• Although the fault code is not displayed in ECM 1
and 2 and if the trouble occurs, conduct this remedy.
NOTE: After the engine stops in 1 to 2 minutes,
pressure may remain inside. When the engine re-starts under this condition, the indicator may not light.
Disconnect connector
A in ECM 1.
Connect terminal #3 of
harness end connector
YES to vehicle frame.
Check if indicator
lights.
Indicator does not
light although engine oil pressure is
low.
· Key switch: ON
Check if indicator
lights when key
switch is turned to
ON position.
YES
Connect the disconnected
connector.
Connect terminal #8 of connector 1-A in monitor unit to
NO vehicle frame.
Check if indicator lights.
· Key switch: ON
· Without disconnecting connector, connect connector to
vehicle frame by using a clip
from the rear of connector.
· Key switch: ON
· Engine: Stopped
NO
YES
Indicator does not
go out after engine
is started.
· Check oil filter for
clogging.
Disconnect connector A in ECM 1.
Check if indicator
goes out.
· Key switch: ON
· Engine: Stopped
YES
NO
Disconnect connector 1-A in monitor unit.
Check if indicator
goes out.
NO
T5-7-30
TROUBLESHOOTING / Troubleshooting C
Faulty ECM 1.
YES
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-A
Open circuit in harness between monitor unit and ECM
1.
Faulty monitor unit.
NO
T183-05-04-013
#8
ECM 1
Connector A
Faulty monitor unit, or burnt
indicator light.
#3
Faulty oil system of ECM 1
and engine, or clogged oil filter.
Shorted circuit in harness
between monitor unit and
ECM 1.
Faulty monitor unit.
T5-7-31
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF OVERHEAT INDICATOR
• Check the wiring connections first.
YES
Disconnect connector
A in ECM 1.
Connect terminal #11
YES
to vehicle frame.
Check if indicator
lights.
Indicator does not
light although engine
overheats.
· Key switch: ON
Check if indicator
lights when key
switch is turned to
ON position.
NO
· Key switch: ON
· Without disconnecting
connector, connect
connector to vehicle
frame by using a clip
from the rear of connector.
· Key switch: ON
NO
YES
Indicator lights although coolant
temperature is low.
Disconnect connector A in ECM
1.
Check if indicator
goes out.
· Key switch: ON
· Engine: Stopped
YES
NO
Connect the disconnected connector.
Connect terminal #7 of
connector 1-A in monitor
unit to vehicle frame.
Check if indicator lights.
Disconnect connector 1-A in monitor
unit.
Check if indicator
goes out.
· Key switch: ON
T5-7-32
NO
TROUBLESHOOTING / Troubleshooting C
Overheat Switch
Coolant Temperature
Operation
Lower than 102±3 °C
OFF
(216±6°F)
102±3 °C (216±6 °F) or
ON
higher
Faulty ECM 1.
YES
Open circuit in harness
between monitor unit and
ECM 1.
Faulty monitor unit.
NO
Faulty monitor unit or
burnt indicator light.
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-A
Faulty overheat switch.
#7
Shorted circuit in harness
between monitor unit and
overheat switch.
ECM 1
Connector A
Faulty monitor unit.
#11
T5-7-33
T183-05-04-013
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF ENGINE WARNING
INDICATOR
Although the fault code is not displayed in ECM 1 and
2 and if the trouble occurs, conduct this remedy.
Although engine is
abnormal, indicator
does not light.
Although engine is
not abnormal, indicator lights.
When key switch is
turned to ON position, check if indicator lights.
Disconnect connector D in ECM
1. Connect termiYES nal #6 of harness
end connector to
vehicle frame.
Check if indicator
lights.
YES
NO
Faulty ECM.
Disconnect
connector 2-B
in monitor unit.
Connect terminal #21 of
monitor end to
vehicle frame.
Check if indicator lights.
YES
Open circuit in
harness between
ECM and monitor
unit.
Faulty monitor unit.
NO
NO
Faulty monitor
unit, or burnt indicator light.
YES
Faulty ECM.
Disconnect connector D in ECM 1.
Check if indicator
goes out.
YES
· Key switch: ON
· Engine: Stopped
NO
Disconnect connector
2-B in monitor unit.
Check if indicator goes
out.
Shorted circuit in
harness between
ECM 1 and monitor unit.
Faulty monitor unit.
NO
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 2-B
ECM 1
Connector D
#21
#6
T4GB-05-05-002
T5-7-34
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF STOP INDICATOR
• When the following troubles occur, the stop indicator
lights in order to announce the trouble to the operator, stop the machine and repair the machine.
• Although the machine is repaired and if the stop indicator does not go out, other indicator on monitor
must light. Refer to the pages corresponding to the
indicator in this group or conduct the remedy according to Troubleshooting A.
• Although there is no trouble and if the stop indicator
does not go out, the logic circuit in monitor unit may
be faulty.
(When the abnormal value is detected, the stop indicator lights;)
• Low engine oil pressure
• Overheat of the engine (high temperature of engine coolant)
• Low level of service brake oil (low level of hydraulic oil tank)
• Low service oil pressure
• High temperature of transmission oil
• Low steering oil pressure
• High temperature of hydraulic oil
T5-7-35
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF SERVICE INDICATOR
• When the following troubles occur, the service indicator lights in order to announce the trouble to the
operator, stop the machine and maintain the machine.
• Although the machine is maintained and if the service indicator does not go out, other indicator on
monitor must light. Refer to the pages corresponding to the indicator in this group or conduct the
remedy according to Troubleshooting A.
• Although there is no trouble and if the service indicator does not go out, the logic circuit in monitor unit
may be faulty.
(When the abnormal value is detected, the service indicator lights;)
• Faulty generation of the alternator
• Clogged air cleaner
• Emergency steering operation
• Lighting the engine warning indicator
• Lighting the transmission warning indicator
• Lighting the maintenance indicator
• High temperature of axle oil
T5-7-36
TROUBLESHOOTING / Troubleshooting C
(Blank)
T5-7-37
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF PARKING BRAKE INDICATOR
• Although the fault code is not displayed in MC and
if the trouble occurs, conduct this remedy.
YES
Disconnect connector B
in MC. Check if indicator
goes out.
Although brake switch is
not turned to Parking position, indicator lights.
YES
Disconnect connector
1-A in monitor unit.
NO Check if indicator goes
out.
NO
YES
When key switch is
turned to ON position,
check if indicator lights.
Although brake switch is
in Parking position, indicator does not light.
Disconnect connector B
in MC.
YES Connect harness end
connector to vehicle
frame.
Check if indicator lights.
· Key switch: ON
NO
· Key switch: ON
· Engine: Stopped
Connector (Harness end of connector viewed from the
open end side)
NO
Monitor Unit
Connector 1-A
MC
Connector Ｂ
T183-05-04-013
#25
#17
T183-05-04-021
T5-7-38
TROUBLESHOOTING / Troubleshooting C
Faulty MC.
Shorted circuit in harness
between monitor unit and
MC.
Faulty monitor unit.
Faulty MC.
Connect the disconnected connector.
Connect terminal #17 of
connector 1-A in monitor
unit to vehicle frame.
Check if indicator lights.
· Key switch: ON
· Without disconnecting connector, connect to vehicle
frame by using a clip from
the rear of connector.
YES
Open circuit in harness between monitor unit and MC.
Faulty monitor unit.
NO
Faulty monitor unit, or burnt
indicator light.
T5-7-39
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF CLEARANCE LIGHT
INDICATOR
• If the light is OFF and the clearance light and indicator light, the light switch may be faulty or the
harness between light switch and clearance light
or monitor unit may be shorted.
• Check the wiring connections first.
YES
Indicator does not light.
Check if clearance light
lights.
· Light switch：ON
Disconnect connector
1-B in monitor unit.
Check if voltage at terminal #21 of harness
end connector is 24 V.
To A
Faulty light switch.
NO
YES
Burnt indicator light.
NO
Open circuit in harness between light switch and monitor
unit.
A
Connector (Harness end of connector viewed from the
open end side)
Monitor Unit
Connector 1-B
#21
T4GB-05-05-002
T5-7-40
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF BRAKE LOW OIL
PRESSURE INDICATOR
• When this trouble occurs, the fault code corresponding to the service brake pressure switch in
monitor unit must be displayed. Refer to Troubleshooting A and conduct the remedy for this
trouble.
• Although the fault cold is not displayed and if the
trouble occurs, the monitor unit may be faulty.
Service Brake Pressure Switch
Pressure
Voltage
Operation
10 Mpa (82 kgf/cm2)
1.32 V or higher
OFF
or higher
Less than 8 Mpa
Less than 1.15 V
ON
(102 kgf/cm2)
T5-7-41
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF BRAKE LOW OIL
LEVEL INDICATOR
• Check the wiring connections first.
YES
Disconnect plug of
YES hydraulic oil level
switch. Check if indicator lights.
Although hydraulic
oil is low, indicator
does not light.
· Key switch: ON
When key switch is
turned to ON position, check if indicator lights.
NO
· Key switch: ON
NO
YES
Although hydraulic
oil is enough, indicator lights.
Disconnect connector of
hydraulic oil level switch.
When terminal of harness end is shorted,
check if indicator goes
out.
· Key switch: ON
YES
NO
Insert a clip into rear of
terminal #13 of connector 1-A in monitor
unit and connect to
vehicle frame.
Check if indicator goes
out.
· Key switch: ON
T5-7-42
NO
Disconnect connector
1-A in monitor unit.
Check if indicator
lights.
TROUBLESHOOTING / Troubleshooting C
Faulty hydraulic oil level
switch.
YES
Shorted circuit in harness
between monitor unit and
hydraulic oil level switch.
Faulty monitor unit.
NO
Faulty monitor unit, or
burnt indicator light.
Faulty hydraulic oil level
switch.
Connector (Harness end of connector viewed from the
open end side)
Open circuit in harness
between monitor unit and
hydraulic oil level switch.
Monitor Unit
Connector 1-A
Faulty monitor unit.
T183-05-04-013
#13
T5-7-43
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION
OF
EMERGENCY
STEERING INDICATOR (Optional)
• After checking if the fault code is not displayed on
Troubleshooting by Dr. ZX, conduct this remedy.
Although emergency steering
check switch is
pushed, emergency
steering pump unit
is not operated.
Disconnect connector of check switch.
Check for continuity
between terminals
#2 and #4 of check
switch end connector.
Connect connector of
check switch.
Disconnect connector
1-A in monitor unit.
YES Connect terminal #14 of
harness end connector
to vehicle frame.
When check switch is
turned ON, check for
continuity.
YES
NO
NO
Faulty alternator system.
Refer to remedy for Malfunction of Alternator Indicator in this group.
YES
After checking monitor
unit light, check if alternator indicator
lights.
· Engine: Running
To A
NO
Faulty emergency steering check switch, or
shorted circuit in harness
between check switch and
monitor unit.
YES
When key switch is
turned ON, emergency steering
pump unit is running
and does not stop.
Open circuit in harness
between emergency
steering check switch
and monitor unit.
Faulty emergency steering check switch.
· Key switch: ON
Although engine
starts, inspection of
emergency steering
pump unit is not
automatically operated.
To A
Disconnect connector
1-A in monitor unit.
Check if pump unit
stops.
YES
· Key switch: ON
NO
Disconnect connector
2-A in monitor unit.
Check if pump unit
stops.
NO
T5-7-44
Shorted circuit in harness
between emergency
steering relay and monitor
unit, or faulty monitor unit.
To C
TROUBLESHOOTING / Troubleshooting C
YES
YES
Replace emergency
steering relay with
horn relay.
Check if horn
sounds.
A
Disconnect connector
2-A in monitor unit.
Connect terminal #11 of
harness end to vehicle
frame.
Check if pump unit is
operated.
· Key switch: ON
Faulty monitor unit.
With connecting terminal
#11 of harness end
connector 2-A in monitor
unit to vehicle frame,
disconnect emergency
NO steering relay.
Connect terminal #2 of
harness end to vehicle
frame.
Check for continuity.
YES
NO
Faulty connector of
emergency steering
relay.
YES
B
Terminals #3 and #5 of
YES emergency steering relay are shorted. Check if
pump unit is operated.
Open circuit in harness between
emergency steering
relay and pump
unit, or faulty pump
unit.
NO
Blown fuse, or open
circuit in harness
between battery
relay and emergency steering relay.
· Key switch: ON
NO
YES
C
Faulty emergency
steering relay.
Replace emergency
steering relay with
horn relay.
Check if pump unit
stops.
· Key switch: ON
Shorted circuit in
wiring and power
circuit between
emergency steering
relay and emergency steering
pump unit, or faulty
emergency steering
pump unit.
NO
Connector (Harness end of connector viewed from the open end side)
Emergency Steering Check
Switch Connector
#4
Open circuit in harness between
monitor unit and
emergency steering
relay.
Faulty emergency
steering relay.
NO
Disconnect emergency steering relay.
Check if voltage at
terminals #1 and #3
of harness end is
about 24 V respectively.
B
Monitor Unit
Connector 1-A
Connector 2-A
Emergency Steering
Relay Connector
#2
#2
#1
#11
4
1
10
5
#5
#2
#14
T5-7-45
T183-05-04-013
#3
T183-05-04-003
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF LOW STEERING OIL
PRESSURE INDICATOR (Optional)
• When this trouble occurs, the fault code corresponding to the emergency steering pressure
switch in monitor unit must be displayed. Refer to
Troubleshooting A and conduct the remedy.
• Although the fault cold is not displayed and if the
trouble occurs, the monitor unit may be faulty.
T5-7-46
TROUBLESHOOTING / Troubleshooting C
(Blank)
T5-7-47
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF DISCHARGE WARNING INDICATOR
• Check the wiring connections first.
Between 12 V
and 35 V
Between 12 Check voltage at terV and 35 V minal #2 of connector
2-A in monitor unit.
When engine starts,
alternator indicator
does not go off.
· Engine: Running
Measure voltage at
terminal L (terminal
#2 of alternator
connector) in alternator.
· Engine: Running
Less than 12 V or
35 V or higher
Less than 12 V or
35 V or higher
Between 12 V
and 35 V
YES
· Engine: Running
YES Check if engine starts.
Although charging
is low, alternator
indicator does not
light.
When key switch is
turn to ON position,
check if indicator
lights.
NO
· Key switch: ON
NO
T5-7-48
Check voltage at
terminal L (terminal #2 of alternator connector) in
alternator.
Less than 12 V or
35 V or higher
TROUBLESHOOTING / Troubleshooting C
Connector (Harness end of connector viewed from the
open end side)
Alternator
Connector
＃2
Faulty monitor unit.
Faulty harness between terminal L in alternator and
monitor unit.
Faulty regulator, or faulty alternator.
Check voltage at
terminal #2 of
connector 2-A in
monitor unit.
Between 12 V
and 35 V
Less than 12 V or
· Engine: Running 35 V or higher
Faulty monitor unit.
Faulty harness between terminal L in alternator and
monitor unit.
Faulty alternator.
Refer to Engine System
Troubleshooting in Troubleshooting B.
Faulty monitor unit, or faulty
alternator indicator.
T5-7-49
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF MONITOR DISPLAY
• The data on monitor display is not displayed by
the signal directly input from the sensors except
one part. The signal data which inputs to other
controllers from the sensors once is input to the
monitor unit by using the CAN communication
and is proceeded in the logic circuit of monitor unit.
Therefore, check if the CAN communication is
normal first and check if the sensors corresponding to the trouble are normal.
Description
Data on liquid
crystal display
Data on data
display
Cause of Trouble
Neutral indicator
Forward/reverse indicator
Driving mode indicator
Hold indicator
Speedometer
Automatic mode indicator
Clutch cut-off indicator
Ride control indicator
Model
Displayed on service mode
when starting only
Clock (24 hours)
Fuel consumption amount
Average fuel consumption amount
Odometer
Displayed on service mode
when starting only
Engine speed
Displayed on service mode
when starting only
Hydraulic
oil Displayed on service mode
temperature
when starting only
Fault code
Displayed on service mode
when starting only
Transmission oil Displayed on service mode
temperature
when starting only
Other data
Displayed on normal mode
when starting only
• Remainder time that hydraulic oil can be used
• Remainder time that hydraulic oil filter can be
used
• Remainder time that transmission oil can be
used
• Remainder time that transmission oil filter can be
used
Remainder time that engine oil can be used
Remainder time that engine oil filter can be used
Remainder time that fuel filter can be used
Hour meter
Coolant temperature
Displayed on service mode
when starting only
T5-7-50
If the data of monitoring function can be displayed on
Dr. ZX, CAN communication between monitor unit
and other controllers is faulty. If the data cannot be
displayed on Dr. ZX, the sensor system detecting the
related signal is faulty. (As for the machine, some
trouble must occur. Refer to Troubleshooting A and
conduct the remedy.)
Refer to T5-7-51.
If the data of monitoring function can be displayed on
Dr. ZX, CAN communication between monitor unit
and other controllers is faulty. If the data cannot be
displayed on Dr. ZX, the sensor system detecting the
related signal is faulty. (As for the machine, some
trouble must occur. Refer to Troubleshooting A and
conduct the remedy.)
As for these troubles, the liquid crystal display in
monitor unit may be faulty or the logic circuit may be
faulty.
The alternator is faulty, the harness between terminal
L in the alternator and terminal #2 of connector 2-A in
monitor unit is faulty, or the clock circuit in monitor
unit may is faulty.
Refer to T5-7-52.
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF RIDE CONTROL INDICATOR
• Check the wiring connections first.
YES
Disconnect connector
1-A in monitor unit.
YES Connect terminal #10 of
harness end to vehicle
frame.
Check for continuity.
When ride control
switch is turned ON,
indicator does not
light.
· Ride control switch: ON
Check if ride control
is operated correctly.
NO
YES
NO
Disconnect connector of
ride control switch.
Connect terminal #7 of
harness end to vehicle
frame.
Check if indicator lights.
NO
Check if ride control is
operated.
YES
NO
Connector (Harness end of connector viewed from the
open end side)
Disconnect connector
1-A in monitor unit.
Check if indicator goes
out.
NO
Ride Control Switch Connector
4
1
10
5
Faulty harness between ride control
switch and monitor
unit.
Faulty ride control
switch.
Faulty harness between terminal #7 of
ride control switch
and monitor unit.
Faulty ride control
switch.
YES
When ride control
switch is turned
OFF, indicator does
not go out.
Faulty monitor unit.
Shorted circuit in
harness between
ride control switch
and monitor unit.
Faulty monitor unit.
Monitor Unit
Connector 1-A
＃10
#7
T183-05-04-013
T5-7-51
TROUBLESHOOTING / Troubleshooting C
MALFUNCTION OF ENGINE COOLANT
TEMPERATURE DISPLAY
• This trouble on coolant temperature operation and
data on monitor display is displayed according to
the signal from the same coolant temperature
sensors. Therefore, when this trouble occurs, the
coolant temperature operation must be faulty.
Refer to the remedy for Malfunction Coolant Temperature Operation in this group and remedy this
trouble first. Although the coolant temperature
operation is not faulty and if this trouble occurs,
the monitor unit is faulty.
T5-7-52
TROUBLESHOOTING / Electrical System Inspection
PRECAUTIONS FOR INSPECTION AND
MAINTENANCE
1. Disconnect the power source.
Remove the harness from the negative terminal
side in battery first when taking wire harnesses
and connectors off for repair or replacement work.
Failure to do so can result in damage to the wire
harnesses, fuses and fusible links and, in some
cases, cause fire due to short circuiting.
2. Color coding of wire harnesses.
As for the color codes of wire harnesses in the
electrical system, refer to the table below.
In cases on the design sheet where two colors
are indicated for one wire, the left initial stands
for base color, while the right initial stands for
marking color.
Code
R
L
Or
Color
Red
Blue
Orange
Code
W
G
Lg
Y
Br
Gr
Yellow
Brown
Gray
B
P
V
Color
White
Green
Light
green
Black
Pink
Violet
NOTE: 1) Code BW indicates a black base wire
with white fine-line marking.
2) Initials “O” and “Or” both stand for the
color orange.
3) Wires with longitudinal stripes printed
on them are not color coded. Do not
confuse them with color coded wires.
T5-8-1
TROUBLESHOOTING / Electrical System Inspection
3. Precautions for connecting and disconnecting
terminal connectors.
1) When disconnecting the harnesses, grasp
them by their connectors. Do not pull on the
wire itself. Release the lock first before
attempting to separate connectors, if a lock
is provided. (Refer to “Instructions for
Disconnecting Connector” on page T5-8-3.)
2) The water-resistant connectors keep water
out. If water enters them, water will not
easily drain from them. When checking the
water-resistant connectors, take extra care
not to allow water to enter the connectors. In
case water should enter the connectors,
reconnect only after the connectors are
thoroughly dried.
3) Before connecting terminal connectors,
check that no terminals are bent or coming
off. In addition, as most connectors are
made of brass, check that no terminals are
rusting.
4) When connecting terminal connectors
provided with a lock, insert them together
until the lock “clicks.”
5) Pull the harness near the connector in order
to check if it is correctly connected.
4. Precaution for using a circuit tester.
1) Before using a circuit tester, refer to the
instructions in the circuit tester manual.
Then, set the circuit tester to meet the object
to be measured, voltage range and current
polarity.
2) Before starting the connector test, always
check the connector terminal numbers,
referring to the circuit diagram.
When the connector size is very small, and
the standard probe size is too large to be
used for testing, wind a fine piece of
sharpened wire or a pin around the probe to
make the test easier.
3) When checking the connector by using a
tester, insert a tester probe from the harness
end of connector in order not to damage the
terminal inside connector.
T5-8-2
Right
Wrong
T107-07-06-001
Right
Rust
Wrong
(Deformation)
Wrong
(Separation)
T107-07-06-002
Wind a Piece of Wire
Tester Probe
Sharpen the end of the Wire
T107-07-06-003
TROUBLESHOOTING / Electrical System Inspection
INSTRUCTIONS
CONNECTORS
FOR
DISCONNECTING
• Pull and Separate Type
• Push, Unlock and Separate Type
NOTE: Connectors will not be easily separated
even if the lock is pushed while being
pulled. Push the lock first before pulling the
connectors.
The lock is located on female side connector (harness end side).
T107-04-05-004
IMPORTANT: Before pulling and separating, release the lock of connector in the
solenoid valve by using a pair of
pincers.
T107-04-05-002
• Raise Lock, Pull and Separate Type
T107-04-05-003
T4GB-05-06-003
T5-8-3
TROUBLESHOOTING / Electrical System Inspection
• Unlock, Move the Lever and Pull Type
NOTE: When unlocking, release the lock by one
hand, slowly pull the lever by another hand,
and separate the connector.
T4GB-05-06-001
T4GB-05-06-002
• Rotate the Lock and Pull Type
NOTE: Pinch the harness end connector, rotate
the projection part counterclockwise while
pushing, and separate the connector.
T4GB-05-06-007
T5-8-4
TROUBLESHOOTING / Electrical System Inspection
(Blank)
T5-8-5
TROUBLESHOOTING / Electrical System Inspection
FUSE INSPECTION
Cracks in a fuse are so fine that it is very difficult or
impossible to find by visual inspection. Use a tester in
order to correctly inspect fuse continuity. Inspect the
fuse by following the instructions described below.
1. Turn Key Switch ON
When the key switch is turned ON, current from
terminal M of key switch activates the battery relay so that electric power is supplied to all circuits.
(Refer to the circuit diagram.)
2. Remove the fuse box cover. Set the tester voltage in order to meet the circuit specification to be
measured.
(Measurement Range: 0 to 30 V)
3. Ground the negative probe of the tester to the
machine. Touch the terminals located away from
the center of the fuse box with the positive probe
of tester one at a time. When normal continuity of
a fuse is intact, the tester will indicate 20 to 25 V
(battery voltage).
NOTE: All terminals located along the lengthwise
centerline of the fuse box are connected to
the power source, while terminals located
away from the center of the fuse box are
connected to loads (accessories). Therefore, test all fuses in the same method except for the glow plug relay circuit fuse.
Check the glow plug relay circuit fuse with
the key switch turned ON according to the
procedure in step 3.
T5-8-6
TROUBLESHOOTING / Electrical System Inspection
(Fuse Box A)
(Fuse Box B)
10
20
30
40
9
19
29
39
8
18
7
17
6
16
5
15
4
3
14
13
2
12
1
11
28
27
26
25
24
23
22
21
38
37
36
35
34
33
32
31
M178-07-034
Fuse NO. Capacity
Connected to
1
10 A
Option (Seta Heater)
2
10 A
12V Converter
3
Option 1
4
15 A
Wiper (Front)
5
5A
Head Light (Right)
6
10 A
Cigar Lighter
7
10 A
ECM1 Power Source
8
10 A
Controller Power Source
9
5A
Parking Brake Relay
10
Option 2
11
5A
Reverse Light
12
10 A
Brake Lamp Relay
13
20 A
Working Light (Front)
14
10 A
Horn
15
5A
Head Light (Left)
16
15 A
Option (Side Wiper 1)
17
15 A
Option (Side Wiper 2)
18
15 A
Option (Window Heater (Front))
19
15 A
Option (Window Heater (Side))
20
10 A
Option (Window Heater (Rear))
21
10A
Option (Fog Lamp)
22
20A
Working Light (Rear)
23
5A
Air Conditioner 1
24
20A
Air Conditioner 2
25
10A
Wiper (Rear)
26
10A
Emergency Steering Pump Unit
27
20A
Ignition
28
15A
Flusher
29
5A
Load Damp Relay
30
5A
Radio
31
10A
Option (Beacon Light)
32
10A
High Beam
33
15A
Fuel Heater
34
10A
Controller (Key: ON)
35
10A
ECM1 (Key: ON)
36
5A
Clearance Lamp 1
37
5A
Clearance Lamp 2
38
10A
MC (Key: ON)
39
10A
Option (Control Unit Power Source)
40
5A
Monitor Unit
T5-8-7
M178-07-034
TROUBLESHOOTING / Electrical System Inspection
FUSIBLE LINK INSPECTION
Inspection
1. Open either battery box cover from left and right
of the machine. Remove the negative cable from
the battery.
2. Open the engine cover on left side of the machine with the front attachment side forward.
3. Remove bolts (M10) (2 used) from the L type
cover. Remove the cover. There are fusible links
(65A) (2 used).
4. Open the black box. There are fusible links (50A)
(2 used) (100A in total).
5. Visually inspect the fusible link.
6. Install the negative cable to the battery.
T4GB-05-06-004
Replacement
1. Check if the negative cable is removed from either battery box from left and right of the machine.
2. Open the engine cover on left side of the machine with the front attachment side forward.
3. Remove bolts (M10) (2 used) from the L type
cover. Remove the cover. There are fusible links
(65A) (2 used).
4. Open the black box. There are fusible links (50A)
(2 used) (100A in total).
5. Pull out and replace the fusible link.
6. Install the negative cable to the battery.
T4GB-05-06-008
Fusible Link (100A)
T5-8-8
Fusible Link (65A)
TROUBLESHOOTING / Electrical System Inspection
BATTERY VOLTAGE CHECK
1. Turn the key switch OFF.
2. Open the battery box cover on left side of the
machine with the front attachment side forward.
3. Check voltage between the battery positive
terminal and the vehicle frame (ground).
Ground to vehicle
frame.
Normal Voltage: 24 V
NOTE: If voltage is abnormal, recharge or replace
the battery.
4. Start the engine. Check voltage between the
battery positive terminal and the vehicle frame
(ground).
Normal Voltage: 26 to 28 V
T4GB-05-06-004
NOTE: If voltage is abnormal, check the charging
system.
T5-8-9
Battery Positive
Terminal
TROUBLESHOOTING / Electrical System Inspection
ALTERNATOR CHECK
In general, the alternator indicator remains off when
the alternator is generating power.
If the alternator indicator comes on while the engine is
running, the alternator may be faulty.
How to Check Alternator
1. Turn the key switch to the ON position. Confirm
that the alternator indicator comes on.
2. Measure voltage between terminals B and E of
the alternator.
If the measured voltage is around 24 V, the alternator circuit can be considered normal.
If the measured voltage is low, a shortage in battery capacity or looseness of the wire connectors
of alternator circuit might be cause of the malfunction.
When voltage is 0 V, the wiring between fuse box
and alternator or the ground line to alternator
might be open circuit.
3. Next, start the engine and measure voltage generated while as the alternator rotates.
As described above, measure voltage between
terminals B and E on the end of alternator.
If voltage is around 28 V, the alternator is operating normally.
If the measured voltage is equal to battery voltage (around 24V), there is some trouble with the
alternator or the regulator.
T5-8-10
B
E
T4HA-05-06-001
TROUBLESHOOTING / Electrical System Inspection
(Blank)
T5-8-11
TROUBLESHOOTING / Electrical System Inspection
CONTINUITY CHECK
Harness
Single-line continuity check
Disconnect both end connectors of the harness and
check continuity between both ends:
If the ohm-meter reading is: 0 Ω = Continuity
∞ Ω = Discontinuity
NOTE: When the one end connector is far apart
from the other, connect one end of
connector (A) to the machine chassis using
a clip. Then, check continuity of the
harness through the vehicle frame as
illustrated.
A
Ω
Connect to
the vehicle
frame.
Connect to
the vehicle
frame.
If the ohm-meter reading is: 0 Ω = Continuity
∞ Ω = Discontinuity
a
Single-line short-circuit check
Disconnect both end connectors of the harness and
check continuity between one end connector of the
harness and the vehicle frame:
If the ohm-meter reading is:
0 Ω = Short circuit is present.
∞ Ω = No short circuit is present.
a
A
Ω
a
A
×
Ω
Short-circuit
between the
harness and
the vehicle
frame.
T107-07-05-003
T5-8-12
TROUBLESHOOTING / Electrical System Inspection
Multi-line continuity check
Disconnect both end connectors of the harness,
and short-circuit two terminals, (A) and (B), at one
end connector, as illustrated. Then, check continuity
between terminals (a) and (b) at the other connector.
If the ohm-meter reading is ∞ Ω, either line (A) - (a),
or (B) - (b) is in discontinuity. To find out which line
is discontinued, conduct the single line continuity
check on both lines individually, or, after changing
the short-circuit terminals from (A) - (B) to (A) - (C),
check continuity once more between terminals (a)
and (c).
First short-circuit
A
B
C
a
b
c
Second short-circuit
Ω
NOTE: By conducting the multi-line continuity
check twice, it is possible to find out which
line is discontinued. With terminals (A) and
(C) short-circuited, check continuity
between terminals (a) and (c).
T107-07-05-004
If the ohm-meter reading is:
0 Ω = Line (B) - (b) has discontinuity.
∞ Ω = Line (A) - (a) has discontinuity.
Multi-line short-circuit check
Disconnect both end connectors of the harness,
and check continuity between terminals (A) and (B)
or (C).
If the ohm-meter reading is:
0 Ω = Short-circuit exists between the lines.
∞ Ω = No short-circuit exists between the lines.
Short-circuit between harnesses.
A
B
C
×
a
b
c
Ω
T107-07-05-005
T5-8-13
TROUBLESHOOTING / Electrical System Inspection
VOLTAGE
MENT
AND
CURRENT
MEASURE-
Turn key switch ON so that the specified voltage (current) is supplied to the location to be measured. Judge
if the circuit is normal by evaluating whether the
measured voltage (current) matches the specification.
24-Volt Circuit
Start checking the circuit in order up to the location to be measured from either power source or
actuator side. Thereby, the faulty location in the
circuit will be found.
Black Probe (Negative) of Tester:
To ground to the vehicle frame
Red Probe (Positive) of Tester:
To touch the location to be measured
Engine
Power Source
Circuit
Key Switch
Location to be Measured
Specification
OFF
OFF
OFF
OFF
OFF
OFF
Between (2) and (1): One Battery
Between (3) and (2): One Battery
Between (3) and (1): Two Batteries
Between (4) and Ground: Battery Power
Between (5) and Ground: Fusible Link
Between (1) and Ground: Backup Current*
10 to 12.5 V
10 to 12.5 V
20 to 25 V
20 to 25 V
20 to 25 V
6 mA
START
START
Between (6) and Ground: Key Switch
Between (7) and Ground: Glow Plug
20 to 25 V
20 to 25 V
START
START
START
START
START
Between (8) and Ground: Key Switch
Between (9) and Ground: Battery Relay (Coil)
Between (10) and Ground: Battery Relay (Switch)
Between (11) and Ground: Starter (B)
Between (12) and Ground: Starter (S)
20 to 25 V
20 to 25 V
20 to 25 V
20 to 25 V
20 to 25 V
Fast Speed
ON
26 to 30 V
Fast Speed
ON
Fast Speed
ON
Between (13) and Ground: Alternator (B) / Generating
Voltage
Between (10) and Ground: Battery Relay / Generating
Voltage
Between (14) and Ground: Monitor
ON→OFF
ON→OFF
ON→OFF
Between (13) and Ground: Alternator (B)
Between (15) and Ground: Load Damp Relay
Between (10) and Ground: Battery Relay
26 to 30 V
26 to 30 V
26 to 30 V
ON
Between (16) and Ground: Radio
20 to 25 V
Stopped
Stopped
Stopped
Stopped
Stopped
Stopped
Preheat Circuit
Started
Started
Starting Circuit
Started
Started
Started
Started
Started
Charging Circuit
26 to 30 V
13 to 30 V
Surge Voltage
Prevention Circuit
Idle Speed
Idle Speed
Idle Speed
Accessory Circuit
Stopped
NOTE: *Measure after disconnecting the negative
cable from the battery.
T5-8-14
TROUBLESHOOTING / Electrical System Inspection
Head Light Switch
Key Switch
8
Fuse Box A
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
6
48
MC
82
83
84
354
355
592
Load Damp
Relay
GPS
627
Neutral Relay
594
76
ICX
1 3 54 2
1 3 54 2
33
Monitor
Unit
15
67
119
233
Radio
14
Fuse Box B
CAN
Coolant
Temperature
Sensor
Glow Relay
ECM1
60
56
233
658
ECM2
115
116
665
Glow Heater
7
16
Intake Air
Temperature
Sensor
Fuel
Injection
Solenoid
Valve
3
Fusible
Link
Fuse
(100A)
9
Battery Relay
5
4
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
2
1
Battery
10
11
13
Starter Motor
12
T4HA-05-06-002
T5-8-15
TROUBLESHOOTING / Electrical System Inspection
5-V Circuit
• Voltage between terminal #1 and the vehicle
frame
With the key switch turned OFF, disconnect the
connector.
Measure voltage between the terminal of 5V power
source on machine harness end connector and the
vehicle frame (ground).
Signal or
Ground
Power
Power
Source
Source
1
Two Polarities
• Key switch: ON
• Tester black probe (negative):
2
V
Vehicle frame (ground)
• Tester red probe (positive):
Terminal of 5V power source
T107-07-05-006
Evaluation:
If the measured voltage is within 5±0.5 V, the circuit
up to terminal of 5V power source is normal.
IMPORTANT: Altough terminal #1 is the teminal of
power source on the illustlation, all
the terminals are not terminals of
power source. Before measurement,
check the electrical circuit diagram
for the connector to be measured.
V
• Voltage between terminal #1 and the ground
terminal
With the key switch turned OFF, disconnect the
sensor connector.
Measure voltage between the terminal of 5V power
source on machine harness end connector and the
ground terminal.
Power
Source Signal Ground
1
2
3
Three Polarities
Power
Source
Two Polarities
1
T107-07-05-007
Signal or
Ground
2
V
• Key switch: ON
• Tester black probe:
Ground terminal
(terminal #2 or #3)
• Tester red probe:
Terminal of 5V power source
Evaluation:
If the measured voltage is within 5±0.5 V, the
circuits up to terminal of 5V power source and
ground terminal are normal.
Three Polarities
IMPORTANT: Altough terminal #1 is the teminal of
power source, terminal #2 is the
signal and #3 is the ground terminal
respectively on the illustlation, all
the connectors are not arranged
similarly.
Before
measurement,
check the electrical circuit diagram
for the connector to be measured.
T5-8-16
Power
Source
1
T107-07-05-008
Signal
2
Ground
3
V
T107-07-05-009
TROUBLESHOOTING / Electrical System Inspection
CHECK BY FALSE SIGNAL
Two Polarities
Turn the key switch OFF and disconnect the sensor
connector. Turn the key switch ON. Connect terminal
of power source and signal terminal on machine harness end connector. (Power voltage is used as a false
signal.)
Check this state by using the monitor function of Dr.
ZX. If the displayed value is the maximum value, the
circuits up to MC and machine harness end connector
are normal. If “ON” is displayed, the pressure switch
circuits are normal.
IMPORTANT: Altough terminal #1 is the teminal of
power source, terminal #2 is the
signal and #3 is the ground terminal
respectively on the illustlation, all
the connectors are not arranged
similarly.
Before
measurement,
check the electrical circuit diagram
for the connector to be measured.
Power
Source
Signal
1
2
Connect
T107-07-05-010
Three Polarities
IMPORTANT: Do not connect terminal of power
source and signal terminal to
ground terminal or to the vehicle
frame (ground) when checking a
three-polarity connector.
Power
Source Signal Ground
1
2
3
Connect
T107-07-05-011
NOTE: Some kinds of sensors can be monitored
by using the service mode of monitor.
(Refer to the TROUBLESHOOTING / Diagnosing Procedure group.)
T5-8-17
TROUBLESHOOTING / Electrical System Inspection
(Blank)
T5-8-18
MEMO
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Hitachi Construction Machinery Co. Ltd
Attn: Publications, Marketing & Product Support
Fax: 81-29-831-1162
Hitachi Ref. No.
SERVICE MANUAL REVISION REQUEST FORM
NAME OF COMPANY:
MODEL:
PUBLICATION NO.:
YOUR NAME:
DATE:
FAX:
(Located at the right top corner in the cover page)
PAGE NO.:
(Located at the bottom center in the page. If two or more revisions are requested, use the comment column)
YOUR COMMENTS / SUGGESTIONS:
Attach photo or sketch if required.
If your need more space, please use another sheet.
REPLY:
(Copy this form for usage)
THE ATTACHED DIAGRAM LIST
(The following diagrams are attached to this manual.)
ZW310 ELECTRIC CIRCUIT DIAGRAM 1 (INCOMPLETION)
ZW310 ELECTRIC CIRCUIT DIAGRAM 2 (INCOMPLETION)
ZW220/250 LIFT ARM PROXIMITY SWITCH HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 LIFT ARM PROXIMITY SWITCH HARNESS
ZW220/250 LIFT ARM ANGLE SENSOR HARNESS (EU STANDARD, GENERAL STANDARD) (OPTIONAL)
ZW310 LIFT ARM ANGLE SENSOR HARNESS (OPTIONAL)
ZW220/250 FRONT LIGHT HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT LIGHT HARNESS
ZW220/250 FRONT HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT HARNESS
ZW220/250 CENTER HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 CENTER HARNESS
ZW220/250 FRONT CONSOLE HARNESS 1 (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT CONSOLE HARNESS 1
ZW220/250 FRONT CONSOLE HARNESS 2 (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT CONSOLE HARNESS 2
ZW220/250 SIDE CONSOLE HARNESS 1 (EU STANDARD, GENERAL STANDARD)
ZW310 SIDE CONSOLE HARNESS 1
ZW220/250 SIDE CONSOLE HARNESS 2 (EU STANDARD, GENERAL STANDARD) (FOR STANDARD TWO
LEVER PILOT VALVE)
ZW310 SIDE CONSOLE HARNESS 2 (FOR STANDARD TWO LEVER PILOT VALVE)
ZW220/250 SIDE CONSOLE HARNESS 3 (EU STANDARD, GENERAL STANDARD) (FOR OPTIONAL JOY
STICK LEVER PILOT VALVE)
ZW310 SIDE CONSOLE HARNESS 3 (FOR OPTIONAL JOY STICK LEVER PILOT VALVE)
ZW310 REAR CONSOLE HARNESS
ZW220/250 TRANSMISSION HARNESS (GENERAL STANDARD)
ZW310 TRANSMISSION HARNESS
ZW310 REAR FRAME HARNESS
ZW310 HYDRAULIC CIRCUIT DIAGRAM (EU STANDARD)
ZW310 HYDRAULIC CIRCUIT DIAGRAM (GENERAL STANDARD)
TROUBLESHOOTING / Troubleshooting B
RELATIONSHIP
BETWEEN
MACHINE
TROUBLE SYMPTOMS AND RELATED
PARTS
This table indicates the relationship between machine
trouble symptoms and the potential problem parts,
which may cause trouble if failed, and the evaluation
methods of these components.
Symptoms in machine
operation when trouble
occurs.
Function
Symptoms in control system when trouble occurs.
Forward/Reverse Lever
• Sends the command signal
• Keeps MC in neutral when
• Although the forward/reverse
Shift Switch
• Sends the command signal
• Particular speed gear only
• When the travel mode switch
Parking Brake Switch
• Releases/applies the parking
• The parking brake cannot be
• Although the parking brake
Travel
Switch
Parts
on Forward/Reverse to MC.
• Sends the signal on forward/reverse to the neutral
relay.
on speed gear to MC.
brake.
traveling.
can be operated according to
condition of the shorted or
open circuit.
released or applied.
lever is operated, the machine does not travel.
• Although the forward/reverse
lever is in Reverse, the backlight and back buzzer are not
operated.
is manually operated, the
machine can travel at particular speed gear only.
• When the travel mode switch
is automatically operated,
speed can be shifted to particular speed gear only.
switch is OFF, the machine
cannot operate in the forward
or reverse direction.
• Although the parking brake
switch is ON on the slope,
the machine moves.
Mode
Selector
• Sends the command signal
• MC makes only the travel
• When the automatic gear
Work
Mode
Switch
Selector
• Sends the command siganl
• MC keeps the work mode
• Although mode L has been
• MC makes the clutch cut-off
• Although mode S,N or D in
on travel mode to MC.
on work mode to MC.
Clutch Cut-Off Position • Sends the command siganl
on clutch cut-off to MC.
Switch
mode in manual gear shifting
operable.
selector switch in Normal
mode.
mode disabled.
shifting is selected, the machine can travel in the travel
mode in manual gear shifting
only.
used, fuel consumption suddenly increases after certain
week or month.
• Machine operation may be
normal according to the
switch to reduce engine output is controlled to low at low
speed gear.
the clutch cut-off mode
switch is selected and the
brake pedal is depressed,
the clutch cut-off is not operated.
Down-Shift Switch
Down-Shift/Up-Shift
Switch
• Sends the command signal
• MC makes
• Although the
Hold Switch
• Sends the command signal
• MC makes hold switch
• Although the auto spped
on down-shift/up-shift switch
to MC. (The circuit in
down-shift switch is
connected to that at
down-shift side in
down-shift/up-shift switch.)
on hold switch to MC.
down-shift/up-shift switch
control disabled.
control disabled.
T5-6-2
down-shift/up-shift switch is
pushed, down-shift/up-shift is
not operated.
• Although the down-shift
switch is pushed, down-shift
is not operated.
gear shifting is selected and
the hold switch is pushed,
travel speed gear is not fixed.
TROUBLESHOOTING / Troubleshooting B
Parts
Symptoms in control system when trouble occurs.
Function
Symptoms in machine
operation when trouble
occurs.
Steering Pilot Valve
• Controls pilot pressure oil • Pilot pressure oil flow rate • According to malfunction, the
Ride Control Valve
• Supplies
Emergency
Steering
Pressure Switch
Emergency
Steering
Pump Delivery Pressure
Switch
Hydraulic Fan Motor
flow rate and direction to the
steering valve spool end
according to steering handle
operating
speed
and
direction.
lift arm cylinder
bottom pressure to the
accumulator through the
chage cut-off spool with the
ride control switch OFF.
• Closes the charge cut-off
spool and blocks the circuit
to lift arm cylinder bottom
side
when
accmulated
pressure in the accumulator
exceeds the specification.
• Operates the solenoid valve
by the command signal from
MC, moves the main spool
and connects the circuits
between lift arm cylinder
bottom
side
and
accumulator, between lift arm
rod side and hydraulic oil
tank when travel speed
reaches 7km/h or faster with
the ride control switch ON.
• Is installed to emergency
steering block in circuit upper
between main pump and
steering valve.
• Sends the signal on steering
circuit pressure to the
monitor unit.
• Is installed to between
emergency steering pump
and emergency steering
block.
• When pressure oil beyond
specification
from
the
emergency steering pump is
supplied, the connection is
broken and the monitor unit
judges that the emergency
steering switch is operated
correctly.
• Operates the flow rate
adjustment solenoid valve by
the command signal from
MC. Controls pressure oil
flow rate to the fan motor by
operating the flow rate
control valve. Increases or
decreases cooling fan speed.
• Operates the reverse control
solenoid
valve
by
the
command signal from MC.
Shifts the outlet port for
pressure oil to the fan motor
by operating the reverse
control valve. Switches the
cooling fan in reverse
rotation.
cannot
properly.
be
controlled
• Pressure
cannot
be
accumulated
in
the
accumulator.
• The solenoid valve and main
spool cannot be controlled.
troubles may occur including;
although the steering handle
is
operataed
fast,
the
steering is operated slowly,
although the steering handle
is operataed slowly, the
steering is operated fast, and
so on.
• Ride control is not operated.
(Shock when traveling is
continued.)
• Ride control can not turned
off. (Shock when traveling is
always reduced.)
• Steering
• Although there is no trouble
• The
• Although
circuit pressure
cannot be detected.
normal
signal
on
pressure occurrence is not
sent to the monitor unit.
in the steering circuit, the
emergency steering pump is
operated.
the emergency
steering pump auto check
circuit is operated when the
engine starts, the emergency
steering
pump
indicator
blinks.
• The flow rate control valve • Cooling fan speed cannot be
cannot be controlled.
controlled.
cannot be controlled.
cannot be operated.
• The reverse control valve • Cooling fan reverse control
T5-6-14
TROUBLESHOOTING / Troubleshooting B
F-11 Lift arm auto leveler is not operated. (Optional)
• Check the wiring connections first.
YES
Check if boom angle of
MC monitor item by
using Dr. ZX is
3.78±0.5 V with lift arm
at highest position.
YES
Check if success is
displayed on angle
sensor learning status
of MC monitor item by
using Dr. ZX.
YES
· Put the matching mark
on lift and shaft by
using a white pen.
Operate the lift arm
several times in order
to check.
To B
NO
· Engine: Running
· Lift arm auto leveler
switch: ON (2 used)
Raise and lower lift
arm.
Check arm angle
sensor shaft rotates
according to link.
To A
Execute lift arm angle
sensor learning.
NO
· Refer to the Operational
Performance Test group.
Tighten link bolt.
NO
· Rotate the shaft to the
position where boom
angle of MC monitor
item by using Dr. ZX is
3.78±0.5 V with lift arm
at the highest position.
Then, tighten link bolt.
Connector (Harness end of connector viewed from the
open end side)
Lift Arm Auto Leveler
Switch Connector
#2
MC
Connector B
Lift Arm Angle Sensor
Connector
MC
Connector D
Lift Arm Solenoid
Valve Connector
#B3
#1
1
2
3
4
1
2
#2
3
1
#1
#B20
T183-05-04-021
T5-6-54
#2
#3
#10
T183-05-04-009
2
THE ATTACHED DIAGRAM LIST
(The following diagrams are attached to this manual.)
ZW310 ELECTRIC CIRCUIT DIAGRAM 1
ZW310 ELECTRIC CIRCUIT DIAGRAM 2
ZW220/250 LIFT ARM PROXIMITY SWITCH HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 LIFT ARM PROXIMITY SWITCH HARNESS
ZW220/250 LIFT ARM ANGLE SENSOR HARNESS (EU STANDARD, GENERAL STANDARD) (OPTIONAL)
ZW310 LIFT ARM ANGLE SENSOR HARNESS (OPTIONAL)
ZW220/250 FRONT LIGHT HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT LIGHT HARNESS
ZW220/250 FRONT HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT HARNESS
ZW220/250 CENTER HARNESS (EU STANDARD, GENERAL STANDARD)
ZW310 CENTER HARNESS
ZW220/250 FRONT CONSOLE HARNESS 1 (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT CONSOLE HARNESS 1
ZW220/250 FRONT CONSOLE HARNESS 2 (EU STANDARD, GENERAL STANDARD)
ZW310 FRONT CONSOLE HARNESS 2
ZW220/250 SIDE CONSOLE HARNESS 1 (EU STANDARD, GENERAL STANDARD)
ZW310 SIDE CONSOLE HARNESS 1
ZW220/250 SIDE CONSOLE HARNESS 2 (EU STANDARD, GENERAL STANDARD) (FOR STANDARD TWO
LEVER PILOT VALVE)
ZW310 SIDE CONSOLE HARNESS 2 (FOR STANDARD TWO LEVER PILOT VALVE)
ZW220/250 SIDE CONSOLE HARNESS 3 (EU STANDARD, GENERAL STANDARD) (FOR OPTIONAL JOY
STICK LEVER PILOT VALVE)
ZW310 SIDE CONSOLE HARNESS 3 (FOR OPTIONAL JOY STICK LEVER PILOT VALVE)
ZW310 REAR CONSOLE HARNESS
ZW220/250 TRANSMISSION HARNESS (GENERAL STANDARD)
ZW310 TRANSMISSION HARNESS
ZW310 REAR FRAME HARNESS
ZW310 HYDRAULIC CIRCUIT DIAGRAM (EU STANDARD)
ZW310 HYDRAULIC CIRCUIT DIAGRAM (GENERAL STANDARD)
INTRODUCTION
TO THE READER
• This manual is written for an experienced technician
to provide technical information needed to maintain
and repair this machine.
• Be sure to thoroughly read this manual for correct product information and service procedures.
• If you have any questions or comments, at if you
found any errors regarding the contents of this
manual, please contact using “Service Manual
Revision Request Form” at the end of this manual.
(Note: Do not tear off the form. Copy it for usage.):
Publications Marketing & Product Support
Hitachi Construction Machinery Co. Ltd.
TEL: 81-29-832-7084
FAX: 81-29-831-1162
ADDITIONAL REFERENCES
• Please refer to the materials listed below in addition
to this manual.
• The Operator’s Manual
• The Parts Catalog
• The Engine Manual
• Parts Catalog of the Engine
• Hitachi Training Material
MANUAL COMPOSITION
• This manual consists of three portions: the Technical Manual (Operational Principle), the Technical
Manual (Troubleshooting) and the Workshop Manual.
• Information included in the Technical Manual
(Operational Principle):
technical information needed for redelivery and
delivery, operation and activation of all devices
and systems.
• Information included in the Technical Manual
(Troubleshooting):
technical information needed for operational performance tests, and troubleshooting procedures.
• Information included in the Workshop Manual:
technical information needed for maintenance
and repair of the machine, tools and devices
needed for maintenance and repair, maintenance
standards, and removal/installation and assemble/disassemble procedures.
PAGE NUMBER
• Each page has a number, located on the center
lower part of the page, and each number contains
the following information:
Example : T 1-3-5
Consecutive Page Number for Each Group
Group Number
Section Number
T: Technical Manual
W: Workshop Manual
IN-01
INTRODUCTION
SAFETY ALERT SYMBOL AND HEADLINE
NOTATIONS
In this manual, the following safety alert symbol and
signal words are used to alert the reader to the
potential for personal injury of machine damage.
This is the safety alert symbol. When you see this
symbol, be alert to the potential for personal injury.
Never fail to follow the safety instructions prescribed
along with the safety alert symbol.
The safety alert symbol is also used to draw attention
to component/part weights.
To avoid injury and damage, be sure to use appropriate lifting techniques and equipment when lifting
heavy parts.
•
CAUTION:
Indicated potentially hazardous situation which
could, if not avoided, result in personal injury or
death.
• IMPORTANT:
Indicates a situation which, if not conformed to the
instructions, could result in damage to the machine.
•
NOTE:
Indicates supplementary technical information or
know-how.
UNITS USED
• SI Units (International System of Units) are used in
Example : 24.5 MPa (250 kgf/cm2, 3560 psi)
this manual.
MKSA system units and English units are also
indicated in parenthheses just behind SI units.
Quantity
Length
Volume
Weight
Force
Torque
To Convert
From
mm
mm
L
L
m3
kg
N
N
N⋅m
N⋅m
Into
Multiply By
in
ft
US gal
US qt
yd3
lb
kgf
lbf
kgf⋅m
lbf⋅ft
0.03937
0.003281
0.2642
1.057
1.308
2.205
0.10197
0.2248
1.0197
0.7375
A table for conversion from SI units to other system
units is shown below for reference purposees.
Quantity
Pressure
Power
Temperature
Velocity
Flow rate
IN-02
To Convert
From
MPa
MPa
kW
kW
°C
km/h
min-1
L/min
mL/rev
Into
Multiply By
kgf/cm2
psi
PS
HP
°F
mph
rpm
US gpm
cc/rev
10.197
145.0
1.360
1.341
°C×1.8+32
0.6214
1.0
0.2642
1.0
SAFETY
RECOGNIZE SAFETY INFORMATION
• These are the SAFETY ALERT SYMBOLS.
• When you see these symbols on your machine or
in operator`s manual, be alert to the potential for
personal injury.
• Follow recommended precautions and safe operating practices.
001-E01A-0001
SA-688
UNDERSTAND SIGNAL WORDS
• On machine safety signs, signal words designating
the degree or level of hazard - DANGER, WARNING,
or CAUTION - are used with the safety alert symbol.
• DANGER indicates an imminently hazardous
situation which, if not avoided, will result in death
or serious injury.
• WARNING indicates a potentially hazardous
situation which, if not avoided, could result in
death or serious injury.
• CAUTION indicates a potentially hazardous
situation
• which, if not avoided, may result in minor or
moderate injury.
• DANGER or WARNING safety signs are located
near specific hazards. General precautions are
listed on CAUTION safety signs.
• Some safety signs don’t use any of the designated signal words above after the safety alert
symbol are occasionally used on this machine.
• To avoid confusing machine protection with personal safety messages, a signal word IMPORTANT indicates a situation which, if not avoided,
could result in damage to the machine.
•
NOTE indicates an additional explanation for
an element of information.
002-E01A-1223
SA-1
SA-1223
SAFETY
FOLLOW SAFETY INSTRUCTIONS
• Carefully read and follow all safety signs on the
machine and all safety messages in operator`s
manual.
• Safety signs should be installed, maintained and
replaced when necessary.
• If a safety sign or operator`s manual is damaged
or missing, order a replacement from your authorized dealer in the same way you order other
replacement parts (be sure to state machine
model and serial number when ordering).
• Learn how to operate the machine and its controls
correctly and safely.
• Allow only trained, qualified, authorized personnel to
operate the machine.
• Keep your machine in proper working condition.
• Unauthorized modifications of the machine may
impair its function and/or safety and affect machine life.
• Do not modify any machine parts without authorization.
Failure to do so may deteriorate the part safety,
function, and/or service life. In addition, personal
accident, machine trouble, and/or damage to
material caused by unauthorized modifications
will void Hitachi Warranty Policy.
• Do not use attachments and/or optional parts or
equipment not authorized by Hitachi. Failure to do
so may deteriorate the safety, function, and/or
service life of the machine. In addition, personal
accident, machine trouble, and/or damage to
material caused by using unauthorized attachments and/or optional parts or equipment will void
Hitachi Warranty Policy.
• The safety messages in this SAFETY chapter are
intended to illustrate basic safety procedures of
machines. However it is impossible for these safety
messages to cover every hazardous situation you
may encounter. If you have any questions, you
should first consult your supervisor and/or your authorized dealer before operating or performing
maintenance work on the machine.
SA-003
003-E01B-0003
PREPARE FOR EMERGENCIES
004-E01A-0437
• Be prepared if a fire starts or if an accident occurs.
• Keep a first aid kit and fire extinguisher on hand.
• Thoroughly read and understand the label attached on the fire extinguisher to use it properly.
• To ensure that a fire-extinguisher can be always
used when necessary, check and service the
fire-extinguisher at the recommended intervals as
specified in the fire-extinguisher manual.
• Establish emergency procedure guidelines to
cope with fires and accidents.
• Keep emergency numbers for doctors, ambulance service, hospital, and fire department
posted near your telephone.
SA-437
SA-2
SAFETY
WEAR PROTECTIVE CLOTHING
• Wear close fitting clothing and safety equipment
appropriate to the job.
You may need:
A hard hat
Safety shoes
Safety glasses, goggles, or face shield
Heavy gloves
Hearing protection
Reflective clothing
Wet weather gear
Respirator or filter mask.
Be sure to wear the correct equipment and clothing
for the job. Do not take any chances.
SA-438
• Avoid wearing loose clothing, jewelry, or other
items that can catch on control levers or other
parts of the machine.
• Operating equipment safely requires the full attention of the operator. Do not wear radio or music
headphones while operating the machine.
005-E01A-0438
PROTECT AGAINST NOISE
• Prolonged exposure to loud noise can cause impairment or loss of hearing.
• Wear a suitable hearing protective device such as
earmuffs or earplugs to protect against objectionable or uncomfortably loud noises.
006-E01A-0434
SA-434
NSPECT MACHINE
• Inspect your machine carefully each day or shift by
walking around it before you start it to avoid personal injury.
• In the walk-around inspection be sure to cover all
points described in the “PRE-START INSPECTION” chapter in the operator’s manual.
007-E01A-0435
SA-435
SA-3
SAFETY
GENERAL PRECAUTIONS FOR CAB
• Before entering the cab, thoroughly remove all dirt
and/or oil from the soles of your work boots. If any
controls such as a pedal is operated while with
dirt and/or oil on the soles of the operator’s work
boots the operator’s foot may slip off the pedal,
possibly resulting in a personal accident.
• Do not leave parts and/or tools lying around the
operator’s seat. Store them in their specified locations.
• Avoid storing transparent bottles in the cab. Do
not attach any transparent type window decorations on the windowpanes as they may focus
sunlight, possibly starting a fire.
• Refrain from listening to the radio, or using music
headphones or mobile telephones in the cab
while operating the machine.
• Keep all flammable objects and/or explosives
away from the machine.
• After using the ashtray, always cover it to extinguish the match and/or tobacco.
• Do not leave cigarette lighters in the cab. When
the temperature in the cab increases, the lighter
may explode.
524-E01A-0000
SA-4
SAFETY
USE HANDHOLDS AND STEPS
• Falling is one of the major causes of personal injury.
• When you get on and off the machine, always
face the machine and maintain a three-point
contact with the steps and handrails.
• Do not use any controls as hand-holds.
• Never jump on or off the machine. Never mount or
dismount a moving machine.
• Be careful of slippery conditions on platforms,
steps, and handrails when leaving the machine.
008-E01A-0439
SA-439
ADJUST THE OPERATOR'S SEAT
• A poorly adjusted seat for either the operator or for
the work at hand may quickly fatigue the operator
leading to misoperations.
• The seat should be adjusted whenever changing
the operator for the machine.
• The operator should be able to fully depress the
pedals and to correctly operate the control levers
with his back against the seat back.
• If not, move the seat forward or backward, and
check again.
• Adjust the rear view mirror position so that the
best rear visibility is obtained from the operator’s
seat. If the mirror is broken, immediately replace it
with a new one.
009-E01A-0462
ENSURE SAFETY BEFORE RISING FROM
OR LEAVING OPERATOR’S SEAT
• Before rising from the operator’s seat to open/close
either side window or to adjust the seat position, be
sure to first lower the front attachment to the ground
and then move the pilot control shut-off lever to the
LOCK position. Failure to do so may allow the machine to unexpectedly move when a body part unintentionally comes in contact with a control lever,
possibly resulting in serious personal injury or death.
• Before leaving the machine, be sure to first lower
the front attachment to the ground and then move
the pilot control shut-off lever to the LOCK position. Turn the key switch OFF to stop the engine.
• Before leaving the machine, close all windows,
doors, and access covers and lock them up.
SA-5
SA-462
SAFETY
FASTEN YOUR SEAT BELT
• If the machine should overturn, the operator may
become injured and/or thrown from the cab. Additionally the operator may be crushed by the overturning machine, resulting in serious injury or death.
• Prior to operating the machine, thoroughly examine webbing, buckle and attaching hardware. If
any item is damaged or worn, replace the seat
belt or component before operating the machine.
• Be sure to remain seated with the seat belt securely fastened at all times when the machine is
in operation to minimize the chance of injury from
an accident.
• We recommend that the seat belt be replaced
every three years regardless of its apparent condition.
SA-237
010-E01A-0237
MOVE AND OPERATE MACHINE SAFELY
• Bystanders can be run over.
• Take extra care not to run over bystanders. Confirm the location of bystanders before moving, or
operating the machine.
• Always keep the travel alarm and horn in working
condition (if equipped). It warns people when the
machine starts to move.
• Use a signal person when moving, swinging, or
operating the machine in congested areas. Coordinate hand signals before starting the machine.
• Use appropriate illumination. Check that all lights
are operable before operating the machine. If any
faulty illumination is present, immediately repair it.
SA-398
011-E01A-0398
HANDLE STARTING AIDS SAFELY
Starting fluid:
• Starting fluid is highly flammable.
• Keep all sparks and flame away when using it.
• Keep starting fluid well away from batteries and
cables.
• Remove container from machine if engine does
not need starting fluid.
• To prevent accidental discharge when storing a
pressurized container, keep the cap on the container, and store it in a cool, well-protected location.
• Do not incinerate or puncture a starting fluid container.
036-E01A-0293-3
SA-6
SA-293
SAFETY
OPERATE
SEAT
ONLY
FROM
OPERATOR'S
• Inappropriate engine starting procedures may cause
the machine to runaway, possibly resulting in serious injury or death.
• Start the engine only when seated in the operator's seat.
• NEVER start the engine while standing on the
track or on ground.
• Do not start engine by shorting across starter
terminals.
• Before starting the engine, confirm that all control
levers are in neutral.
• Before starting the engine, confirm the safety
around the machine and sound the horn to alert
bystanders.
SA-431
012-E01B-0431
JUMP STARTING
• Battery gas can explode, resulting in serious injury.
• If the engine must be jump started, be sure to
follow the instructions shown in the “OPERATING
THE ENGINE” chapter in the operator’s manual.
• The operator must be in the operator’s seat so
that the machine will be under control when the
engine starts.
• Jump starting is a two-person operation.
• Never use a frozen battery.
• Failure to follow correct jump starting procedures
could result in a battery explosion or a runaway
machine.
SA-032
S013-E01A-0032 SA-032
SA-7
SAFETY
INVESTIGATE JOB SITE BEFOREHAND
• When working at the edge of an excavation or on a
road shoulder, the machine could tip over, possibly
resulting in serious injury or death.
• Investigate the configuration and ground conditions of the job site beforehand to prevent the
machine from falling and to prevent the ground,
stockpiles, or banks from collapsing.
• Make a work plan. Use machines appropriate to
the work and job site.
• Reinforce ground, edges, and road shoulders as
necessary. Keep the machine well back from the
edges of excavations and road shoulders.
• When working on an incline or on a road shoulder,
employ a signal person as required.
• Confirm that your machine is equipped a FOPS
cab before working in areas where the possibility
of falling stones or debris exist.
• When the footing is weak, reinforce the ground
before starting work.
• When working on frozen ground, be extremely
alert. As ambient temperatures rise, footing becomes loose and slippery.
• Beware the possibility of fire when operating the
machine near flammable objects such as dry
grass.
015-E01B-0447
SA-8
SA-447
SAFETY
EQUIPMENT OF HEAD GUARD, ROPS,
FOPS
In case the machine is operated in areas where the
possibility of falling stones or debris exist, equip a
head guard, ROPS, or FOPS according to the potential hazardous conditions. (The standard cab for this
machine corresponds to ROPS and FOPS.)
ROPS: Roll-Over Protective Structure
FOPS: Falling Object Protective Structure
SA-521
PROVIDE SIGNALS FOR JOBS INVOLVING MULTIPLE NUMBERS OF MACHINES
• For jobs involving multiple numbers of machines,
provide signals commonly known by all personnel
involved. Also, appoint a signal person to coordinate
the job site. Make sure that all personnel obey the
signal person’s directions.
018-E01A-0481
SA-481
SA-9
SAFETY
KEEP RIDERS OFF MACHINE
• Riders on machine are subject to injury such as being struck by foreign objects and being thrown off
the machine.
• Only the operator should be on the machine.
Keep riders off.
• Riders also obstruct the operator’s view, resulting
in the machine being operated in an unsafe
manner.
014-E01B-0427
SA-427
DRIVE SAFELY
• Beware of the possibility of slipping and/or turning
over the machine when driving on a slope.
• When driving on level ground, hold the bucket at
mark (A) 400 to 500 mm above the ground as illustrated.
• Avoid driving over any obstacles.
• Drive the machine slowly when driving on rough
terrain.
• Avoid quick direction changes. Failure to do so
may cause the machine to turn over.
• If the engine stops while driving, the steering
function becomes inoperative. Immediately stop
the machine by applying the bake to prevent
personal accident.
SA-448
019-E07A-0448
DRIVE MACHINE SAFELY (WORK SITE)
• Before driving the machine, always confirm that the
steering wheel/F-N-R lever direction corresponds to
the direction you wish to drive.
• Be sure to detour around any obstructions.
• Driving on a slope may cause the machine to slip or
overturn, possibly resulting in serious injury or
death.
• When driving up or down a slope, keep the bucket
facing the direction of travel, approximately 200 to
300 mm (approximately 8 to 12 in) (A) above the
ground.
• If the machine starts to skid or becomes unstable,
immediately lower the bucket to the ground and
stop.
SA-449
SA-450
• Driving across the face of a slope or steering on a
slope may cause the machine to skid or overturn. If
the direction must be changed, move the machine to
level ground, then, change the direction to ensure
safe operation.
019-E05B-0515
SA-451
SA-10
SAFETY
DRIVE SAFELY WITH BUCKET LOADED
• If the machine is incorrectly operated while driving
with the bucket loaded, turning over of the machine
may result. Be sure to follow all the instructions indicated below.
• When driving the machine on a job site with the
bucket loaded, hold the bucket as low as possible
to keep the machine balanced and to have good
visibility.
• Do not exceed the rated load capacity. Always
operate the machine within the rated load capacity.
• Avoid fast starts, stops, and quick turns. Failure to
do so may result in personal injury and/or death.
• Avoid rapid drive direction changes which could
possibly cause personal injury and/or death.
SA-400
051-E02A-0400
DRIVE ON SNOW SAFELY
• Beware of the possibility of slipping or turning over
the machine when driving on frozen snow surfaces.
• The machine may slip more easily than expected
on frozen snow surfaces even if the inclination is
small. Reduce speed when driving. Avoid fast
starts, stops and quick turns.
• Road shoulder and/or set-up utilities covered with
snow are difficult to locate. Be sure where they
are before removing snow.
• Be sure to use tire chains when driving on snow.
• Avoid applying the brake for quick stops on snow.
If a quick stop is required, lower the bucket to the
ground.
SA-452
052-E02A-0452
TRAVEL ON PUBLIC ROADS SAFELY
• This machine is not allowed to drive on public loads
with the bucket loaded.
• Be sure to empty the bucket.
• Hold the bucket at mark (A) 400 to 500 mm above
the road surface as illustrated.
053-E02A-0453
SA-453
SA-11
SAFETY
AVOID INJURY FROM ROLLAWAY ACCIDENTS
• Death or serious injury may result if you attempt to
mount or stop a moving machine.
To avoid rollaways:
• Select level ground when possible to park machine.
• Do not park the machine on a grade.
• Lower the bucket to the ground.
• Place the F-N-R lever in neutral, and put the park
brake switch in the ON (parking brake) position.
• Run the engine at slow idle speed without load for
5 minutes to cool down the engine.
• Stop the engine and remove the key from the key
switch.
• Pull the lock lever to LOCK position.
• Block both tires and lower the bucket to the
ground.
• Position the machine to prevent rolling.
• Park a reasonable distance from other machines.
SA-457
020-E02A-0516
SA-458
SA-12
SAFETY
AVOID ACCIDENTS FROM BACKING UP
AND TURNING
• Make sure no one is working under or close to the
machine before backing up or turning the machine
to avoid personal injury and/or death by being run
over or entangled in the machine.
• Keep all personnel away from the machine by
sounding the horn and/or using hand signals. Use
extra care to be sure no one is in from the articulation area before turning the machine.
• Keep windows, mirrors, and lights in good condition.
• Reduce travel speed when dust, heavy rain, fog,
etc., reduce the visibility.
• In case good visibility is not obtained, use a signal
person to guide you.
SA-383
021-E02A-0517
SA-312
SA-13
SAFETY
AVOID POSITIONING
ANYONE
BUCKET
OVER
• Never allow the bucket to pass over co-workers
and/or the dump truck operator’s cab. Falling soil
from the bucket or contact with bucket may cause
serious personal accidents and/or damage to the
machine.
• Avoid carrying the bucket over the co-workers to
ensure safe operation.
023-E02A-0518
SA-518
AVOID TIPPING
DO NOT ATTEMPT TO JUMP CLEAR OF TIPPING
MACHINE. MACHINE WILL TIP OVER FASTER
THAN YOU CAN JUMP FREE, POSSIBLY RESULTING IN SERIOUS PERSONAL INJURY OR
DEATH. IF TIPPING OVER OF THE MACHINE IS
PREDICTED, SECURELY HOLD THE STEERING
WHEEL TO PREVENT YOUR BODY FROM BEING
THROWN OUT OF THE MACHINE.
MACHINE WILL TIP OVER FASTER THAN YOU
CAN JUMP FREE
FASTEN YOUR SEAT BELT
• The danger of tipping is always present when operating on a grade, possibly resulting in serious injury
or death.
To avoid tipping:
• Be extra careful before operating on a grade.
• Prepare machine operating area flat.
• Keep the bucket low to the ground and close to
the machine.
• Reduce operating speeds to avoid tipping or slipping.
• Avoid changing direction when traveling on
grades.
• NEVER attempt to travel across a grade steeper
than 5 degrees if crossing the grade is unavoidable.
• Reduce swing speed as necessary when swinging loads.
• Be careful when working on frozen ground.
• Temperature increases will cause the ground to
become soft and make ground travel unstable.
SA-14
SA-463
SAFETY
NEVER UNDERCUT A HIGH BANK
• The edges could collapse or a land slide could occur
causing serious injury or death.
026-E01A-0519
SA-519
DIG WITH CAUTION
Before digging, check the location of cables, gas lines,
and water lines.
027-E01A-0396
SA-396
PERFORM TRUCK LOADING SAFELY
• Do not operate the machine involuntarily. Unexpected machine movement may cause personal injury and/or death.
• Do not lower the bucket with the loader control
lever in the FLOAT position. The bucket may free
fall, possibly causing personal injury and/or death.
• Always select a level surface for truck loading.
028-E01A-397
SA-397
SA-15
SAFETY
AVOID POWER LINES
Serious injury or death can result from contact with
electric lines.
Never move any part of the machine or load closer to
any electric line than 3 m (10 ft) plus twice the line
insulator length.
29-E01A-0455
SA-455
PRECAUTIONS FOR OPERATION
• If the front attachment or any part of the machine
comes in contact with an overhead obstacle, both
the machine and the overhead obstacle may become damaged, and personal injury may result.
• Take care to avoid coming in contact with overhead obstacles with the bucket or arm during operation.
PRECAUTIONS FOR LIGHTENING
• The machine is vulnerable to lighting strikes.
• In the event of an electrical storm, immediately
stop operation, and lower the bucket to the
ground. Evacuate to a safe place far away from
the machine.
• After the electrical storm has passed, check all of
the machine safety devices for any failure. If any
failed safety devices are found, operate the machine only after repairing them.
OBJECT HANDLING
• If a lifted load should fall, any person nearby may be
struck by the falling load or may be crushed underneath it, resulting in serious injury or death.
• When using the machine for craning operations,
be sure to comply with all local regulations.
• Do not use damaged chains or frayed cables,
sables, slings, or ropes.
• Before craning, position the upperstructure with
the position of the bucket support located on the
chassis at the front.
• Move the load slowly and carefully. Never move it
suddenly.
• Keep all persons well away from the load.
• Never move a load over a person's head.
• Do not allow anyone to approach the load until it
is safely and securely situated on supporting
blocks or on the ground.
• Never attach a sling or chain to the bucket teeth.
They may come off, causing the load to fall.
032-E01A-0132
SA-16
SA-132
SAFETY
PROTECT AGAINST FLYING DEBRIS
• If flying debris hit eyes or any other part of the body,
serious injury may result.
• Guard against injury from flying pieces of metal or
debris; wear goggles or safety glasses.
• Keep bystanders away from the working area
before striking any object.
031-E01A-0432
SA-432
PARK MACHINE SAFELY
To avoid accidents:
• Park machine on a firm, level surface.
• Lower bucket to the ground.
• Place the F-N-R lever in neutral, and put the park
brake switch in the ON (parking brake) position.
• Run engine at slow idle speed without load for 5
minutes.
• Turn key switch to OFF to stop engine.
• Remove the key from the key switch.
• Lower the lock lever to the LOCK position.
• Close windows, roof vent, and cab door.
• Lock all access doors and compartments.
033-E07B-0456
SA-17
SA-456
SAFETY
STORE ATTACHMENTS SAFELY
• Stored attachments such as buckets, hydraulic
hammers, and blades can fall and cause serious
injury or death.
• Securely store attachments and implements to
prevent falling. Keep children and bystanders
away from storage areas.
504-E01A-0034
SA-034
TRANSPORT SAFELY
• Take care the machine may turn over when loading
or unloading the machine onto or off of a truck or
trailer.
• Observe the related regulations and rules for safe
transportation.
• Select an appropriate truck or trailer for the machine to be transported.
• Be sure to use a signal person.
• Always follow the following precautions for loading or unloading:
1. Select solid and level ground.
2. Always use a ramp or deck strong enough to
support the machine weight.
3. Use the low speed gear.
4. Never steer the machine while on the ramp. If the
traveling direction must be changed while the
ramp, unload the machine from the ramp, reposition the machine on the ground, then try loading
again.
5. After loading, install the lock bar to securely hold
the articulation mechanism.
6. Wedge the front and rear of tires. Securely hold
the machine to the truck or trailer deck with wire
ropes.
Be sure to further follow the details described in the
TRANSPORTING section.
035-E07A-0454
SA-18
Less than 15°
SA-454
SAFETY
HANDLE FLUIDS SAFELY-AVOID FIRES
• Handle fuel with care; it is highly flammable. If fuel
ignites, an explosion and/or a fire may occur, possibly resulting in serious injury or death.
• Do not refuel the machine while smoking or when
near open flame or sparks.
• Always stop the engine before refueling the machine.
• Fill the fuel tank outdoors.
• All fuels, most lubricants, and some coolants are
flammable.
• Store flammable fluids well away from fire hazards.
• Do not incinerate or puncture pressurized containers.
• Do not store oily rags; they can ignite and burn
spontaneously.
• Securely tighten the fuel and oil filler cap.
SA-018
034-E01A-0496
SA-019
SA-19
SAFETY
PRACTICE SAFE MAINTENANCE
To avoid accidents:
• Understand service procedures before starting
work.
• Keep the work area clean and dry.
• Do not spray water or steam inside cab.
• Never lubricate or service the machine while it is
moving.
• Keep hands, feet and clothing away from
power-driven parts.
Before servicing the machine:
1. Park the machine on a level surface.
2. Lower the bucket to the ground.
3. Turn the auto-idle switch off.
4. Run the engine at slow idle speed without load for
5 minutes.
5. Turn the key switch to OFF to stop engine.
6. Relieve the pressure in the hydraulic system by
moving the control levers several times.
7. Remove the key from the switch.
8. Attach a “Do Not Operate” tag on the control
lever.
9. Lower the lock lever to the LOCK position.
10. Lock bar connects the front and rear frames.
11. Allow the engine to cool.
SA-028
• If a maintenance procedure must be performed
with the engine running, do not leave machine
unattended.
• Never work under a machine raised by the lift
arm.
• Inspect certain parts periodically and repair or replace as necessary. Refer to the section discussing that part in the “MAINTENANCE” chapter of
operator`s manual.
• Keep all parts in good condition and properly installed.
• Fix damage immediately. Replace worn or broken
parts. Remove any buildup of grease, oil, or debris.
• When cleaning parts, always use nonflammable
detergent oil. Never use highly flammable oil such
as fuel oil and gasoline to clean parts or surfaces.
• Disconnect battery ground cable (-) before making adjustments to electrical systems or before
performing welding on the machine.
SA-312
SA-134
500-E02C-0520
SA-527
SA-20
SAFETY
• Sufficiently illuminate the work site. Use a maintenance work light when working under or inside
the machine.
• Always use a work light protected with a guard. In
case the light bulb is broken, spilled fuel, oil, antifreeze fluid, or window washer fluid may catch fire.
SA-037
WARN OTHERS OF SERVICE WORK
• Unexpected machine movement can cause serious
injury.
• Before performing any work on the machine, attach a “Do Not Operate” tag on the control lever.
This tag is available from your authorized dealer.
501-E01A-0287
SS2045102
SUPPORT MACHINE PROPERLY
• Never attempt to work on the machine without securing the machine first.
• Always lower the attachment to the ground before
you work on the machine.
• If you must work on a lifted machine or attachment, securely support the machine or attachment. Do not support the machine on cinder
blocks, hollow tires, or props that may crumble
under continuous load. Do not work under a machine that is supported solely by a jack.
519-E01A-0527
SA-527
STAY CLEAR OF MOVING PARTS
• Entanglement in moving parts can cause serious
injury.
• To prevent accidents, care should be taken to
ensure that hands, feet, clothing, jewelry and hair
do not become entangled when working around
rotating parts.
502-E01A-0026
SA-026
SA-21
SAFETY
SUPPORT MAINTENANCE PROPERLY
• Explosive separation of a tire and rim parts can
cause serious injury or death.
• Do not attempt to mount a tire unless you have
the proper equipment and experience to perform
the job. Have it done by your authorized dealer or
a qualified repair service.
• Always maintain the correct tire pressure. DO
NOT inflate tire above the recommended pressure.
• When inflating tires, use a chip-on chuck and extension hose long enough to allow you to stand to
one side and not in front of or over the tire assembly. Use a safety cage it available.
• Inspect tires and wheels daily. Do not operate with
low pressure, cuts bubbles, damaged rims, or
missing lug bolts and nuts.
• Never cut or weld on an inflated tire or rim assembly. Heat from welding could cause an increase in pressure and may result in tire explosion.
SA-249
521-E02A-0249
PREVENT PARTS FROM FLYING
• Travel reduction gears are under pressure.
• As pieces may fly off, be sure to keep body and
face away from AIR RELEASE PLUG to avoid
injury.
• GEAR OIL is hot. Wait for GEAR OIL to cool, then
gradually loosen AIR RELEASE PLUG to release
pressure.
503-E03A-0344
SA-344
SA-22
SAFETY
PREVENT BURNS
Hot spraying fluids:
• After operation, engine coolant is hot and under
pressure. Hot water or steam is contained in the
engine, radiator and heater lines.
Skin contact with escaping hot water or steam can
cause severe burns.
• To avoid possible injury from hot spraying water.
DO NOT remove the radiator cap until the engine
is cool. When opening, turn the cap slowly to the
stop. Allow all pressure to be released before
removing the cap.
• The hydraulic oil tank is pressurized. Again, be
sure to release all pressure before removing the
cap.
SA-039
Hot fluids and surfaces:
• Engine oil, gear oil and hydraulic oil also become
hot during operation.
The engine, hoses, lines and other parts become
hot as well.
• Wait for the oil and components to cool before
starting any maintenance or inspection work.
SA-225
505-E01B-0498
REPLACE
CALLY
RUBBER
HOSES
PERIODI-
• Rubber hoses that contain flammable fluids under
pressure may break due to aging, fatigue, and abrasion. It is very difficult to gauge the extent of deterioration due to aging, fatigue, and abrasion of rubber hoses by inspection alone.
• Periodically replace the rubber hoses. (See the
page of “Periodic replacement of parts” in the operator’s manual.)
• Failure to periodically replace rubber hoses may
cause a fire, fluid injection into skin, or the front attachment to fall on a person nearby, which may result in severe burns, gangrene, or otherwise serious
injury or death.
S506-E01A-0019
SA-23
SA-019
SAFETY
AVOID HIGH-PRESSURE FLUIDS
• Fluids such as diesel fuel or hydraulic oil under
pressure can penetrate the skin or eyes causing serious injury, blindness or death.
• Avoid this hazard by relieving pressure before
disconnecting hydraulic or other lines.
• Tighten all connections before applying pressure.
• Search for leaks with a piece of cardboard; take
care to protect hands and body from
high-pressure fluids. Wear a face shield or goggles for eye protection.
• If an accident occurs, see a doctor familiar with
this type of injury immediately. Any fluid injected
into the skin must be surgically removed within a
few hours or gangrene may result.
SA-031
507-E03A-0499
SA-292
SA-044
SA-24
SAFETY
PREVENT FIRES
Check for Oil Leaks:
• Fuel, hydraulic oil and lubricant leaks can lead to
fires.
• Check for oil leaks due to missing or loose clamps,
kinked hoses, lines or hoses that rub against each
other, damage to the oil-cooler, and loose
oil-cooler flange bolts.
• Tighten, repair or replace any missing, loose or
damaged clamps, lines, hoses, oil-cooler and
oil-cooler flange bolts.
• Do not bend or strike high-pressure lines.
• Never install bent or damaged lines, pipes, or
hoses.
Check for Shorts:
• Short circuits can cause fires.
• Clean and tighten all electrical connections.
• Check before each shift or after eight(8) to ten(10)
hours operation for loose, kinked, hardened or
frayed electrical cables and wires.
• Check before each shift or after eight(8) to ten(10)
hours operation for missing or damaged terminal
caps.
• DO NOT OPERATE MACHINE if cable or wires
are loose, kinked, etc..
Clean up Flammables:
• Spilled fuel and oil, and trash, grease, debris, accumulated coal dust, and other flammables may
cause fires.
• Prevent fires by inspecting and cleaning the machine daily and by removing spilled or accumulated flammables immediately.
Check Key Switch:
• If a fire breaks out, failure to stop the engine will
escalate the fire, hampering fire fighting.
Always check key switch function before operating
the machine every day:
1. Start the engine and run it at slow idle.
2. Turn the key switch to the OFF position to confirm
that the engine stops.
• If any abnormalities are found, be sure to repair
them before operating the machine.
508-E02B-0019
Check Heat Shields:
• Damaged or missing heat shields may lead to fires.
• Damaged or missing heat shields must be repaired or replaced before operating the machine.
508-E02A-0393
SA-25
SA-019
SAFETY
EVACUATING IN CASE OF FIRE
• If a fire breaks out, evacuate the machine in the following way:
• Stop the engine by turning the key switch to the
OFF position if there is time.
• Use a fire extinguisher if there is time.
• Exit the machine.
518-E01A-0393
SA-393
BEWARE OF EXHAUST FUMES
• Prevent asphyxiation. Engine exhaust fumes can
cause sickness or death.
• If you must operate in a building, be sure there is
adequate ventilation. Either use an exhaust pipe
extension to remove the exhaust fumes or open
doors and windows to bring enough outside air
into the area.
509-E01A-0016
SA-016
PRECAUTIONS
GRINDING
FOR
WELDING
AND
• Welding may generate gas and/or small fires.
• Be sure to perform welding in a well ventilated
and prepared area. Store flammable objects in a
safe place before starting welding.
• Only qualified personnel should perform welding.
Never allow an unqualified person to perform
welding.
• Grinding on the machine may create fire hazards.
Store flammable objects in a safe place before
starting grinding.
• After finishing welding and grinding, recheck that
there are no abnormalities such as the area surrounding the welded area still smoldering.
523-E01A-0818
SA-26
SA-818
SAFETY
AVOID HEATING NEAR PRESSURIZED
FLUID LINES
• Flammable spray can be generated by heating near
pressurized fluid lines, resulting in severe burns to
yourself and bystanders.
• Do not heat by welding, soldering, or using a torch
near pressurized fluid lines or other flammable
materials.
• Pressurized lines can be accidentally cut when
heat goes beyond the immediate flame area. Install temporary fireresistant guards to protect
hoses or other materials before engaging in
welding, soldering, etc..
SA-030
AVOID APPLYING HEAT TO LINES CONTAINING FLAMMABLE FLUIDS
• Do not weld or flame cut pipes or tubes that contain flammable fluids.
• Clean them thoroughly with nonflammable solvent
before welding or flame cutting them.
510-E01B-0030
REMOVE PAINT BEFORE WELDING OR
HEATING
• Hazardous fumes can be generated when paint is
heated by welding, soldering, or using a torch. If
inhaled, these fumes may cause sickness.
• Avoid potentially toxic fumes and dust.
• Do all such work outside or in a well-ventilated
area. Dispose of paint and solvent properly.
• Remove paint before welding or heating:
1. If you sand or grind paint, avoid breathing the dust.
Wear an approved respirator.
2. If you use solvent or paint stripper, remove stripper with soap and water before welding. Remove
solvent or paint stripper containers and other
flammable material from area. Allow fumes to
disperse at least 15 minutes before welding or
heating.
511-E01A-0029
SA-27
SA-029
SAFETY
BEWARE OF ASBESTOS DUST
• Take care not to inhale dust produced in the work
site. Inhalation of asbestos fibers may be the cause
of lung cancer.
• Depending on the wok site conditions, the risk of
inhaling asbestos fiber may exist. Spray water to
prevent asbestos from becoming airborne. Do not
use compressed air.
• When operating the machine in a work site where
asbestos might be present, be sure to operate the
machine from the upwind side and wear a mask
rated to prevent the inhalation of asbestos.
• Keep bystanders out of the work site during operation.
• Asbestos might be present in imitation parts. Use
only genuine Hitachi Parts.
SA-029
PREVENT BATTERY EXPLOSIONS
• Battery gas can explode.
• Keep sparks, lighted matches, and flame away
from the top of battery.
• Never check battery charge by placing a metal
object across the posts. Use a voltmeter or hydrometer.
• Do not charge a frozen battery; it may explode.
Warm the battery to 16 °C (60 °F) first.
• Do not continue to use or charge the battery when
electrolyte level is lower than specified. Explosion
of the battery may result.
• Loose terminals may produce sparks. Securely
tighten all terminals.
SA-032
• Battery electrolyte is poisonous. If the battery should
explode, battery electrolyte may be splashed into
eyes, possibly resulting in blindness.
• Be sure to wear eye protection when checking
electrolyte specific gravity.
512-E01B-0032
SERVICE AIR CONDITIONING SYSTEM
SAFELY
• If spilled onto skin, refrigerant may cause a cold
contact burn.
• Refer to the instructions described on the container for proper use when handling the refrigerant.
• Use a recovery and recycling system to avoid
leaking refrigerant into the atmosphere.
• Never touch the refrigerant.
513-E01A-0405
SA-28
SA-405
SAFETY
HANDLE CHEMICAL PRODUCTS SAFELY
• Direct exposure to hazardous chemicals can cause
serious injury. Potentially hazardous chemicals used
with your machine include such items as lubricants,
coolants, paints, and adhesives.
• A Material Safety Data Sheet (MSDS) provides
specific details on chemical products: physical
and health hazards, safety procedures, and
emergency response techniques.
• Check the MSDS before you start any job using a
hazardous chemical. That way you will know exactly what the risks are and how to do the job
safely. Then follow procedures and use recommended equipment.
• See your authorized dealer for MSDS’s (available
only in English) on chemical products used with
your machine.
SA-309
515-E01A-0309
DISPOSE OF WASTE PROPERLY
• Improperly disposing of waste can threaten the environment and ecology. Potentially harmful waste
used with HITACHI equipment includes such items
as oil, fuel, coolant, brake fluid, filters, and batteries.
• Use leakproof containers when draining fluids. Do
not use food or beverage containers that may
mislead someone into drinking from them.
• Do not pour waste onto the ground, down a drain,
or into any water source.
• Air conditioning refrigerants escaping into the air
can
• damage the Earth’s atmosphere. Government
regulations may require a certified air conditioning
service center to recover and recycle used air
conditioning refrigerants.
• Inquire on the proper way to recycle or dispose of
waste from your local environmental or recycling
center, or from your authorized dealer.
516-E01A-0226
SA-29
SA-226
SAFETY
BEFORE RETURNING THE MACHINE TO
THE CUSTOMER
• After maintenance or repair work is complete,
confirm that:
• The machine is functioning properly, especially
the safety systems.
• Worn or damaged parts have been repaired or
replaced.
S517-E01A-0435
SA-435
SA-30
SECTION AND GROUP
CONTENTS
SECTION 1 GENERAL
Group 1 Precautions for disassembling
and Assembling
Group 2 Tightening
Group 3 Painting
Group 4 Bleed Air from Hydraulic Oil Tank
SECTION 2 BODY (UPPERSTRUCTURE)
WORKSHOP MANUAL
Group 1 Cab
Group 2 Counterweight
Group 3 Center Hinge
Group 4 Hood
Group 5 Hydraulic Oil Tank
Group 6 Pump Device
Group 7 Control Valve
Group 8 Pilot Valve
Group 9 Pilot Shut-Off Valve
Group 10 Hydraulic Fan Pump and Motor
SECTION 3 BODY (TRAVEL SYSTEM)
All information, illustrations and specifications in this manual are based on
the latest product information available
at the time of publication. The right is
reserved to make changes at any time
without notice.
Group 1 Tire
Group 2 Drive Unit
Group 3 Axle
Group 4 Propeller Shaft
Group 5 Brake Valve
Group 6 Charging Block
Group 7 Steering Pilot Valve
Group 8 Steering Valve
Group 9 Steering Cylinder
SECTION 4 FRONT ATTACHMENT
Group 1 Front Attachment
Group 2 Cylinder
COPYRIGHT(C)2007
Hitachi Construction Machinery Co., Ltd.
Tokyo, Japan
All rights reserved
TECHNICAL MANUAL (Operational Principle)
SECTION 1 GENERAL
Group 1 Specification
Group 2 Component Layout
Group 3 Component Specifications
SECTION 2 SYSTEM
Group 1 Control System
Group 2 ECM System
Group 3 Hydraulic System
Group 4 Electrical System
SECTION 3 COMPONENT OPERATION
Group 1 Pump Device
Group 2 Control Valve
Group 3 Hydraulic Fan Motor
Group 4 Steering Pilot Valve
Group 5 Steering Valve
Group 6 Pilot Valve
Group 7 Charging Block
Group 8 Ride Control Valve
Group 9 Drive Unit
Group 10 Axle
Group 11 Brake Valve
Group 12 Others
TECHNICAL MANUAL (Troubleshooting)
SECTION 4 OPERATIONAL PERFORMANCE TEST
Group 1 Introduction
Group 2 Standard
Group 3 Engine Test
Group 4 Wheel Loader Test
Group 5 Component Test
Group 6 Adjustment
SECTION 5 TROUBLESHOOTING
Group 1 Diagnosing Procedure
Group 2 Dr. ZX
Group 3 e-Wheel
Group 4 Component Layout
Group 5 Troubleshooting A
Group 6 Troubleshooting B
Group 7 Troubleshooting C
Group 8 Electrical System Inspection
SECTION 1
GENERAL
⎯ CONTENTS ⎯
Group 1 Precautions for Disassembling
and Assembling
Precautions for Disassembling and
Assembling ............................................ W1-1-1
Maintenance Standard Terminology......... W1-1-7
Group 2 Tightening
Tightening Torque Specifications ............. W1-2-1
Torque Chart............................................ W1-2-2
Piping Joint.............................................. W1-2-5
Periodic Replacement Parts .................... W1-2-9
Group 3 Painting
Painting ................................................... W1-3-1
Group 4 Bleed Air from Hydraulic Oil Tank
Bleed Air from Hydraulic Oil Tank ............ W1-4-1
4HAW-1-1
(Blank)
4HAW-1-2
GENERAL / Precautions for Disassembling and Assembling
PRECAUTIONS FOR
AND ASSEMBLING
DISASSEMBLING
Precautions for Disassembling and Assembling
• Clean the Machine
• Precautions for Disassembling
Thoroughly wash the machine before bringing it into
the shop. Bringing a dirty machine into the shop
may cause machine components to be
contaminated during disassembling/assembling,
resulting in damage to machine components, as
well as decreased efficiency in service work.
• Inspect the Machine
Be
sure
to
thoroughly
understand
all
disassem-bling/assembling procedures beforehand,
to help avoid incorrect disassembling of
components as well as personal injury.
Check and record the items listed below to prevent
problems from occurring in the future.
• The machine model, machine serial number, and
hour meter reading.
• Reason for disassembly (symptoms, failed parts,
and causes).
• Clogging of filters and oil, water or air leaks, if
any.
• Capacities and condition of lubricants.
• Loose or damaged parts.
• Prepare and Clean Tools and Disassembly Area
Prepare the necessary tools to be used and the
area for disassembling work.
W1-1-1
• To prevent dirt from entering, cap or plug the
removed pipes.
• Before disassembling, clean the exterior of the
components and place on a work bench.
• Before disassembling, drain gear oil from the
reduction gear.
• Be sure to provide appropriate containers for
draining fluids.
• Use matching marks for easier reassembling.
• Be sure to use the specified special tools, when
instructed.
• If a part or component cannot be removed after
removing its securing nuts and bolts, do not
attempt to remove it forcibly. Find the cause(s),
then take the appropriate measures to remove it.
• Orderly arrange disassembled parts. Mark and
tag them as necessary.
• Store common parts, such as bolts and nuts with
reference to where they are to be used and in a
manner that will prevent loss.
• Inspect the contact or sliding surfaces of
disassembled parts for abnormal wear, sticking,
or other damage.
• Measure and record the degree of wear and
clearances.
GENERAL / Precautions for Disassembling and Assembling
• Precautions for Assembling
Bleeding Air from Hydraulic System
• Be sure to clean all parts and inspect them for
any damage. If any damage is found, repair or
replace part.
• Dirt or debris on the contact or sliding surfaces
may shorten the service life of the machine. Take
care not to contaminate any contact or sliding
surfaces.
• Be sure to replace O-rings, backup rings, and oil
seals with new ones once they are disassembled.
Apply a film of grease before installing.
• Be sure that liquid-gasket-applied surfaces are
clean and dry.
• If an anti-corrosive agent has been used on a
new part, be sure to thoroughly clean the part to
remove the agent.
• Utilize matching marks when assembling.
• Be sure to use the designated tools to assemble
bearings, bushings and oil seals.
• Keep a record of the number of tools used for
disassembly/assembly. After assembling is
complete, count the number of tools, so as to
make sure that no forgotten tools remain in the
assembled machine.
When hydraulic oil is drained, the suction filter or the
suction lines are replaced, or the removal and installation of the pump, swing motor, travel motor or
cylinder is done, bleed air from the hydraulic system
in the following procedures:
IMPORTANT: If the engine is started with air
trapped in the hydraulic pump housing, damage to the pump may result.
If the cylinder is operated with air
trapped in the cylinder tube, damage to the cylinder may result.
Be sure to bleed air before starting
the engine.
• Bleeding Air from Hydraulic Pump
W1-1-2
• Remove the air bleeding plug from the top of the
pump and fill the pump housing with hydraulic oil.
• After the pump housing is filled with hydraulic oil,
temporarily tighten the plug. Then, start the engine and run at slow idle speed.
• Slightly loosen the plug to bleed air from the
pump housing until hydraulic oil oozes out.
• After bleeding all the air, securely tighten the
plug.
GENERAL / Precautions for Disassembling and Assembling
• Bleeding Air from Hydraulic Circuit
• After refilling hydraulic oil, start the engine. While
operating each cylinder, operate the machine
under light loads for 10 to 15 minutes. Slowly
start each operation (never fully stroke the cylinders during initial operation stage). As the pilot oil
circuit has an air bleed device, air trapped in the
pilot oil circuit will be bled while performing the
above operation for approx. 5 minutes.
• Reposition the front attachment to check hydraulic oil level.
• Stop the engine. Recheck hydraulic oil level. Replenish oil as necessary.
W1-1-3
W4GB-01-01-001
GENERAL / Precautions for Disassembling and Assembling
Floating Seal Precautions
A
1. In general, replace the floating seal with a new
one after disassembling.
If the floating seal is to be reused, follow these
procedures:
(1) Keep seal rings together as a matched set
with seal ring faces together. Insert a piece of
cardboard to protect surfaces.
(2) Check sliding surface (C) on seal ring (A) for
scuffing, scoring, corrosion, deformation or
uneven wear.
(3) Check O-ring (B) for
deformation or hardening.
tears,
B
W105-03-05-019
breaks,
2. If incorrectly assembled, oil leakage or damage
will occur. Be sure to do the following, to prevent
trouble.
(1) Clean the floating seal and seal mounting
bores with cleaning solvent.
Use a wire brush to remove mud, rust or dirt.
After cleaning, thoroughly dry parts with
compressed air.
Correct
Incorrect
(2) Clean the floating seal and seal mounting
bores. Check the bore surface for scuffing or
scoring by touching the surface with touch.
(3) Check that O-ring (B) is not twisted, and that it
is installed correctly on seal ring (A).
(4) After installing the floating seal, check that
seal ring surface (C) is parallel with seal
mating face (D) by measuring the distances
(C) and (D) at point (a) and (b), as illustrated.
If these distances differ, correct O-ring (B)
seating.
Correct
D
W105-03-05-020
Incorrect
a
a
C
B
b
a=b
b
a≠b
W110-03-05-004
W1-1-4
GENERAL / Precautions for Disassembling and Assembling
Precautions for Using Nylon Sling
1. Follow the precautions below to use nylon slings
safely.
• Attach protectors (soft material) on the corners of
the load so that the nylon sling does not directly
contact the corners. This will prevent the nylon
sling from being damaged and the lifted load from
slipping.
• Lower the temperature of the lifted load to lower
than 100 °C (212 °F). If unavoidably lifting a load
with a temperature of 100 °C (212 °F) or more,
reduce the load weight.
• Do not lift acid or alkali chemicals.
• Take care not to allow the sling to become wet.
The load may slip.
• When required to use more than one sling, use
slings with the same width and length to keep the
lifted load balanced.
• When lifting a load using an eyehole, be sure to
eliminate any gaps between the sling and load.
(Refer to the right illustration.) Reduce the load
weight so that it is less than 80 % of the sling
breaking force.
• Avoid using twisted, bound, connected, or
hitched slings.
• Do not place any object on twisted or bent slings.
(Refer to the right illustration.)
• When removing the slings from under the load,
take care not to damage the nylon slings. Avoid
contact with protrusions.
• Avoid dragging slings on the ground, throwing
slings or pushing slings with a metal object.
• When using with other types of slings (wire rope)
or accessories (shackle), protect the joint so that
the nylon sling is not damaged.
• Store the nylon slings indoors so they won’t deteriorate with heat, sun light, or chemicals.
Correct Eyehole
Lifting Method
W102-04-02-016
Incorrect Eyehole
Lifting Method
W105-04-01-008
Bent Sling
W1-1-5
W162-01-01-009
GENERAL / Precautions for Disassembling and Assembling
CAUTION: If a load is lifted with a damaged
nylon sling, serious personal injury may result. Be sure to visually check the nylon sling
for any damage before using.
Damaged Appearance
2. Before using a nylon sling, visually check the nylon sling for any damage corresponding to examples shown to the right. If any damage is found,
cut and discard the sling. Even if no damage is
found, do not use slings older than 7-years.
Broken Sewing Thread
W162-01-01-002
Scuffing
W162-01-01-003
Fuzz
Broken Sewing
Thread
W162-01-01-004
Broken Sewing
Thread
W162-01-01-005
Broken Sewing
Thread
Scoring
Fuzz
Separation of
Belt
Scuffing
W162-01-01-006
W162-01-01-007
Broken Warp
W162-01-01-008
W1-1-6
GENERAL / Precautions for Disassembling and Assembling
MAINTENANCE STANDARD TERMINOLOGY
“Standard”
1. Dimension for parts on a new machine.
2. Dimension of new components or assemblies
adjusted to specification.
“Allowable Limit”
1. Normal machine performance cannot be accomplished after exceeding this limit.
2. Repair or adjustment is impossible after exceeding this limit.
3. Therefore, in consideration of operation efficiency
and maintenance expense, proper maintenance
shall be carried out before reaching the “Allowable Limit”.
W1-1-7
GENERAL / Precautions for Disassembling and Assembling
(Blank)
W1-1-8
GENERAL / Tightening
TIGHTENING TORQUE SPECIFICATIONS
Bolts and Nuts of Machine: Standard Tightening Torque Chart
Descriptions
Bolt Dia.
Q’ty
Wrench
Size (mm)
Torque
N⋅m (kgf⋅m)
1
Front axle mounting bolt
30
8
46
1579 (161)
2
Rear axle support mounting bolt
30
8
46
1579 (161)
3
Wheel rim mounting bolt
24
80
36
890 (91)
4
Propeller shaft mounting bolt
12
20
17
**143 (15)
5
Propeller shaft support bearing mounting bolt
20
2
30
206 (21)
6
Transmission mounting bolt; bracket
16
8
24
224 (23)
7
Transmission mounting bolt; cushion rubber
18
4
27
**315 (32)
8
Engine mounting bolt; bracket
14
8
22
180 (18)
9
Engine mounting bolt; cushion rubber
18
2
27
315 (32)
12
4
17
34.2(3)
12
4
19
100 (10)
16
2
24
200 (20)
16
1
24
205 (21)
11 Counterweight mounting bolt
30
4
46
1510 (154)
12 Flange above upper center pin fixing
16
10
24
224 (23)
13 Lower center pin stopper
16
1
24
86.9 (9)
14 Loader front pin stopper
16
13
24
86.9 (9)
15 Steering cylinder pin stopper
16
4
24
86.9 (9)
16 Radiator frame mounting bolt
16
6
24
**154 (16)
17 Radiator mounting bolt
10
4
14
39 to 49 (4 to 5)
18 Intercooler mounting bolt
12
6
17
67 to 83 (7 to 8)
19 Oil cooler mounting bolt
10
8
14
39 to 49 (4 to 5)
20 Air conditioner condenser mounting bolt
8
4
12
12.5 (1)
21 Air conditioner compressor mounting bolt
8
4
12
23 to 30 (2 to 3)
16
4
24
**205 (21)
11/4’
16
46
1940 (198)
24 Cutting edge mounting bolt
＊
12
37.47
1068 (109)
25 Wear plate mounting bolt
＊
8
37.47
1068(109)
10 Muffler mounting bolt
22 Cab cushion rubber
＊
23 Bucket teeth mounting bolt (optional)
1’
1’
As for the bolt Dia. with mark *, the dimension is indicated in inch.
As for torque with mark **, LOCTITE #262 is used.
NOTE: When tightening, apply lubricant in order to reduce friction coefficient of bolts and nuts.
(Ex. white zinc B dissolved into spindle oil)
Remove rust, dirt and dust before installing fasteners.
W1-2-1
GENERAL / Tightening
TORQUE CHART
CAUTION: Use tools appropriate for the work
to be done. The make-do tools or parts are
dangerous. As the incorrect size tools are
slipped or removed, personal injury may be
caused.
Bolt Types
Tighten the nuts or bolts correctly to the torque
specifications.
As the different types and grades of bolt are used,
use and tighten the correct bolts correctly when assembling the machine or components.
SA-040
Specified Tightening Torque
Hexagon Wrench
Bolt
Dia.
(mm)
Target Value
Allowable Value
Target Value
Allowable Value
Target Value
Wrench
Size
M4GB-07-123
mm
Allowable Value
N⋅m kgf⋅cm
N⋅m
N⋅m
kgf⋅cm
N⋅m
N⋅m
kgf⋅cm
N⋅m
3.06
31.2
2.45 to 3.67 25.0 to 37.4 4.49
45.8
M4GB-07-121
kgf⋅cm
M4GB-07-122
kgf⋅cm
kgf⋅cm
4
1.15 11.7
0.92 to 1.38 9.4 to 14.1
3.60 to 5.39 36.7 to 55.0
5
2.36 24.1
1.89 to 2.82 19.3 to 28.8
6.30
64.2
5.03 to 7.55 51.3 to 77.0 9.24
94.2
7.40 to 11.1 75.5 to 113
8
6
4.98 40.6
3.20 to 4.79 32.6 to 48.8
10.6
108
8.50 to 12.7 86.7 to 130
15.6
159
12.6 to 18.7 128 to 191
10
8
9.81
100
7.84 to 11.7 79.9 to 119
26.1
266
20.9 to 31.0 213 to 319
38.3
391
30.7 to 46.0 313 to 469
13
10 19.5
199
15.6 to 23.4 159 to 239
52.1
531
41.6 to 62.5 424 to 638
76.5
780
61.2 to 91.8 624 to 936
17
12 34.2
349
27.5 to 41.1 280 to 419
91.2
930
73.1 to 109 745 to 1110
133
1360
108 to 161 1100 to 1640
19
14 55.0
561
43.9 to65.9
448 to 672
146
1490
117 to 177 1190 to 1800 216
2200
173 to 258 1760 to 2630
22
16 86.9
886
69.5 to 104 709 to 1060
232
2370
185 to 279 1890 to 2840 341
3480
272 to 409 2770 to 4170
24
18
118 1200
94.6 to 142 965 to 1450
315
3210
252 to 379 2570 to 3860 463
4720
370 to 555 3770 to 5660
27
20
171 1740
136 to204 1390 to 2080 452
4610
362 to 543 3690 to 5540 665
6780
534 to 797 5440 to 8130
30
22
234 2390
187 to252 1910 to 2570 624
6360
499 to 749 5090 to 7640 918
9360
734 to 1100
32
7480 to
7
11200
24
293 2990
234 to 352 2390 to 3590 782
7970
626 to 938 6380 to 9560 1150
11700 919 to 1380
9370 to
36
14100
27
436 4450
349 to 524 3560 to 5340 1160
11800 931 to 1400
9490 to
14000 to 20900
41
14300
1720 17500
1370 to
2050
30
588 6000
471 to 706 4800 to 7200 1570 16000 1260 to 1880
12800 to
19200
2300 23500 1840 to 277018800 to 28200
46
33
810 8260
648 to 972 6610 to 9910 2160 22000 1730 to 2590
17600 to
26400
3170 32300
2540 to
3810
25900 to 38800
50
36 1030 10500 828 to 1250 8440 to 12700 2770 28200 2210 to 3310
22500 to
4060 41400
3240 to
33000 to 49600
55
43200 to 64800
60
33800
39 1350 13800 1080 to 1140 11000 to 11650 3600 36700 2880 to 4320
29400 to
44100
W1-2-2
4860
5290 53900
4240 to
6350
GENERAL / Tightening
Specified Tightening Torque
Bolt
Socket Bolt
Wrench
Dia.
Target Value
(mm)
N⋅m
kgf⋅cm
N⋅m
kgf⋅cm
4
4.49
45.8
3.60 to 5.39
36.7 to 55.0
3
5
9.24
94.2
7.40 to 11.1
75.5 to 113
4
6
15.6
159
12.6 to 18.7
128 to 191
5
8
38.3
391
30.7 to 46.0
313 to 469
6
10
76.5
780
61.2 to 91.8
624 to 936
8
12
133
1360
108 to 161
1100 to 1640
10
14
216
2200
173 to 258
1760 to 2630
12
16
341
3480
272 to 409
2770 to 4170
14
18
463
4720
370 to 555
3770 to 5660
14
20
665
6780
534 to 797
5440 to 8130
17
Size
Allowable Value
(mm)
22
918
9360
734 to 1100
7480 to 11200
17
24
1150
11700
919 to 1380
9370 to 14100
19
27
1720
17500
1370 to 2050 14000 to 20900
19
30
2300
23500
1840 to 2770 18800 to 28200
22
33
3170
32300
2540 to 3810 25900 to 38800
24
36
4060
41400
3240 to 4860 33000 to 49600
27
39
5290
53900
4240 to 6350 43200 to 64800
27
IMPORTANT: The following items are applied to
both fine and coarse pitch threads.
1. When tightening, apply lubricant in
order to reduce friction coefficient
of bolts and nuts. (Ex. white zinc B
dissolved into spindle oil)
2. Torque tolerance is ±20 %.
3. Use the bolts of correct length. The
bolts that are too long cannot be
tightened as the bolt tip comes into
contact with the bottom of bolt hole.
The bolts that are too short cannot
develop sufficient tightening force.
4. The torques given in table on the
previous page are for general use
only. Do not use these torques if a
different torque is given for a specific application.
5. Clean the nut and bolt threads and
remove dirt or corrosion before installing.
Tightening Order
When tightening two or more bolts, tighten them alternately, as shown, to ensure even tightening.
Equally tighten upper
and lower alternately
Tighten diagonally
1
1.4
12
9
4
1
6
7
14
13
8
5
2
3
10
11
3
6
4
2.3
Tighten from center and diagonally
5
2
W105-01-01-003
W1-2-3
GENERAL / Tightening
Precautions for Spilt Flange
IMPORTANT: 1. Clean the sealing surfaces. Check
if the scratches / roughness that
cause leaks and damage of O-ring
are found.
2. Use only specified O-rings. Inspect O-rings for any damage. Do
not file the O-ring surfaces. When
installing O-ring into a groove,
use grease in order to hold O-ring
in place.
3. While tightening the bolt by hand,
check that flange is installed to
the port correctly. Do not pinch
the O-ring.
4. Tighten the bolts alternately and
diagonally, in order to ensure
even tightening to the specified
torque.
5. Do not use air wrenches. Using an
air wrench often causes tightening of one bolt fully before tighten
the others, resulting in damage to
O-rings or uneven tightening of
bolts.
W105-01-01-015
WRONG
W105-01-01-016
W105-01-01-008
WRONG
RIGHT
Nut and Bolt Locking
• Lock Plate
IMPORTANT: Do not reuse the lock plates. Do not
try to bend the same point twice.
• Split Pin
IMPORTANT: Do not align the holes in the bolt and
nut while loosening. Tighten and
align anytime. Do not reuse the cotter pins.
• Wire
IMPORTANT: Attach a wire to bolts in the
bolt-tightening direction. Do not reuse the wire.
Do not bend it round
Bend along edge sharply
RIGHT
RIGHT
WRONG
Bend along edge sharply
W105-01-01-009
RIGHT
RIGHT
RIGHT
WRONG
Loosen
WRONG
Tighten
W105-01-01-010
W1-2-4
GENERAL / Tightening
PIPING JOINT
4
1
3
5
2
IMPORTANT: The torques given in the chart below
are for general use only.
Do not use these torques if a different torque is given for a specific application.
M202-07-051
Union Joint
Metal sealing surfaces (4) and (5) of adapter (1) and
hose (2) fit together to seal pressure oil. Union joints
are used to join small-diameter lines.
Joint Body
37°
IMPORTANT: 1. Do not over-tighten nut (3). Excessive force will be applied to
metal sealing surfaces (4) and (5),
possibly cracking adapter (1). Be
sure to tighten nut (3) to specifications.
2. Scratches or other damage to
sealing surfaces (4) or (5) will
cause oil leakage at the joint.
Take care not to damage them
when connecting/disconnecting.
Description
37°female
Female Union Joint
W4GB-01-02-001
Wrench Size
mm
Union Nut
17
19
22
27
32
36
Wrench Size
mm
Joint Body
14
17
19
22
27
32
Tightening Torque
N⋅m (kgf⋅m, lbf⋅ft)
24.5 (2.5, 18)
29.5 (3.0, 21.5)
39 (4.0, 28.5)
93 (9.5, 69)
137 (14.0, 101)
175 (18.0, 129)
NOTE: Tightening torque of 37°male coupling without union is similar
to tightening torque of 37°female.
W1-2-5
GENERAL / Tightening
O-ring Seal Joint
O-ring (6) is installed against the end face of adapter
(7) and seals pressure oil.
IMPORTANT: 1. Replace O-ring (6) with a new one
when reinstalling.
2. Before tightening union nut (9),
confirm that O-ring (6) is seated
correctly in O-ring groove (8).
Tightening union nut (9) with
O-ring (6) displaced will damage
O-ring (6), resulting in oil leakage.
3. Do not damage O-ring groove (8)
or sealing surface (10) in adapter
(7). Damage to O-ring (6) may
cause oil leakage.
4. If union nut (9) is found to be
loose, causing oil leakage, do not
tighten it to stop the leak. Instead,
replace O-ring (6) with a new one,
then tighten union nut (9) after
confirming that O-ring (6) is securely seated in place.
7
6
8 10
9
Joint Body
M104-07-033
Wrench Size
mm
Union Nut
27
32
36
41
50
W1-2-6
Wrench Size
mm
Joint Body
22
27
30,32
36
46
Tightening Torque
N⋅m (kgf⋅m, lbf⋅ft)
93 (9.5, 69)
137 (14.0, 101)
175 (18.0, 129)
205 (21.0, 151)
330 (33.7, 243)
GENERAL / Tightening
Screw-In Connection
Depending on types of screw and sealing, different
types of screw-in connection are used.
PT
IMPORTANT: Check that the thread pitch and
thread type (tapered or straight) are
the correct type before using any
screw-in connection.
(In general, the screw-in connection
of male tapered thread is used except when measuring.))
Seal Tape Application
Seal tape is used in order to seal clearances between male and female threads so that any leaks
between threads may be prevented. Apply just
enough seal tape to fill up thread clearances. Do not
overwrap.
30°
Male Tapered Thread
PF
Male Straight Thread
W105-01-01-018
Wrench Size
mm
Joint Body
19
22
27
36
41
50
60
• Application Procedure
Tightening Torque
N⋅m (kgf⋅m, lbf⋅ft)
FC material
SS material
14.5 (1.5,10.5)
34 (3.5,25)
29.5 (3.0,21.5)
49 (5.0,36)
49 (5.0,36)
93 (9.5,69)
69 (7.0,51)
157 (16,116)
108 (11,80)
205 (21,151)
157 (16,116)
320 (33,235)
195 (20,144)
Internal Thread
Check that the thread surface is clean and, free of
dirt or damage. Apply the seal tape around threads
in order to leave one to two pitch threads uncovered.
Wrap the seal tape in the same direction as the
threads.
External Thread
Clearance
W105-01-01-019
Low-Pressure-Hose Clamp Tightening
Low-pressure-hose clamp tightening torque differs
depending on the type of clamp.
T-Bolt Type Band Clamp:
4.4 N⋅m (0.45 kgf⋅m, 3.25 lbf⋅ft )
Worm Gear Type Band Clamp:
5.9 to 6.9 N⋅m (0.6 to 0.7 kg⋅m, 4.3 to 5.1 lbf⋅ft)
Leave one to two pitch threads uncovered
M114-07-041
T-Bolt Type Band Clamp
M114-07-043
W1-2-7
Worm Gear Type Band Clamp
M114-07-042
GENERAL / Tightening
Connecting Hose
RIGHT
WRONG
CAUTION: When replacing the hoses, use
only genuine Hitachi service parts. Using
hoses other than genuine Hitachi hoses may
cause oil leaks, hose rupture or separation of
fitting, possibly resulting in a fire on the
machine.
Do not install hoses kinked. Application of
high oil pressure, vibration, or an impact to a
kinked hose may result in oil leaks, hose
rupture or separation of fitting. Utilize the
print marks on hoses when installing in order
to prevent hose from being kinked.
Take necessary measures to protect hoses
from rubbing against each other. If the hoses
rub against each other, wear to the hoses
may result and lead to hose rupture.
Take care so that the hoses do not come into
contact with the moving parts or sharp objects.
W105-01-01-011
WRONG
RIGHT
Rubbing Against
Each Other
W105-01-01-012
WRONG
Clamp
RIGHT
Clamp
Rubbing Against
Each Other
W105-01-01-013
WRONG
Rubbing Against
Each Other
RIGHT
Clamp
W105-01-01-014
W1-2-8
GENERAL / Tightening
PERIODIC REPLACEMENT PARTS
1. Periodic Replacement Parts (1) (Safety Inspection Object)
In order to ensure safe operation, the users must
conduct daily checking before starting operation and
periodic inspection of the machine by law.
In order to ensure safe operation, conduct periodic
replacement of the security parts below.
Replacement Parts
Name
Engine
Brake system
Steering system
Replacement
Intervals
Replacement Cause
Fire breaking may occur because of fuel leakage.
Fuel tank
Hose
Every 2 years
Brake valve
Seals (rubber)
Every 1 year
Wet-type brake
D-ring in piston
Brake pipe
Hose
Stop Lamp
Switch
Every 4 years If oil leakage occurs when
Every 2 years traveling, the machine cannot
be controlled.
Every 2 years
Accumulator
Accumulator (3 used)
Every 2 years
Steering pipe
Hose
Every 2 years
Steering cylinder
Seals (rubber)
Every 4 years
Steering valve
Seals (rubber)
Every 2 years
1. Theses parts deteriorate, fatigue and weaken with
time. As it is very difficult to gauge extent of the
damaged parts according to periodic inspection,
replace them with the new ones regardless of
defect in the interval.
2. If any of these parts are found to be defective
regardless of the interval, repair or replace these
parts.
W1-2-9
If oil leakage occurs, the
steering cannot be controlled.
GENERAL / Tightening
2. Periodic Replacement Parts (2)
In order to ensure safe operation, conduct periodic
inspection of the machine.In order to ensure safe
operation further, conduct periodic replacement of
the parts below specially related to safety.
Theses parts deteriorate, fatigue and weaken with
time. This may cause serious personal/impersonal
hazard. As it is very difficult to gauge remnant life of
these parts according to driving sensation or
appearance inspection, replace them with the new
ones regardless of defect in the interval.
If any of these parts are found to be defective
according to periodic inspection regardless of the
interval, replace these parts
Replacement Parts Name
Pump
Suction hose
Delivery hose
Every 2 years
Working system
Bucket cylinder hose
Pilot hose
Lift arm cylinder line hose
Every 2 years
Seat belt
Seat belt
Every 3 years
Hydraulic system
Driver’s seat
Replacement
Intervals
NOTE: Replace O-rings and the gaskets when
replacing the hoses.
W1-2-10
GENERAL / Painting
PAINTING
4
6
1
19
21
20
12
25
24
13
14
15
16
17
23
5
18
22
2
7
5
3
9
5
10
8
11
W4GB-01-03-001
1
2
3
4
5
Surfaces to Be Painted
Body
Deck Plate
Handrail
Front Fender
Fender Cover
6 Lamp Bracket
Step
7
Painting Colour
TAXI Yellow
HG Beige Deep
Warm Gray
TAXI Yellow
Not painted
Warm Gray
Warm Gray
15
16
17
18
19
20
21
8 Rear Step
TAXI Yellow
9 Rear Fender
HG Beige Deep
10 Full Fender
HG Beige Deep
11 Fuel Tank
TAXI Yellow
12 Oil Tank
HG Beige Deep
13 Side Cover
TAXI Yellow
14 Lower Cover
HG Beige Deep
IMPORTANT: When
cleaning
around
front
attachment or cylinder, etc. fitted
with HN bushing, do not pour
washing liquid directly on the
bushing.
The ambient temperature should not
exceed 70 °C (158 °F) when painting
and drying.
22
23
24
25
W1-3-1
Surfaces to Be Painted
Painting Colour
Rear Grill
Not painted
Counterweight
TAXI Yellow
Battery Box
TAXI Yellow
Cockpit Skirt
HG Beige Deep
HG Beige Deep
Cockpit and mounting parts
(Valve control box and so on)
Outside of Cab
HG Beige Deep
Inside and Outside Surface of HG Beige Deep
Cab
Articulate lock Bar
Red
Rim
TAXI Yellow
Tail Pipe
Not painted
Pre-Cleaner
Not painted
GENERAL / Painting
(Blank)
W1-3-2
GENERAL / Bleed Air From Hydraulic Oil Tank
BLEED AIR FROM HYDRAULIC OIL TANK
CAUTION: Escaping fluid under pressure
may penetrate the skin and eyes, and cause
serious injury. Release the pressure before
removing hydraulic or other lines.
Hot hydraulic oil just after operation may
spout and cause severe burns. Wait for oil in
order to cool before starting any work.
Do not turn the cap on hydraulic oil tank
quickly. The cap may fly off by internal
pressure. Release any remaining pressure
and remove the cap.
Preparation
1. Park the machine on a solid, level surface. Lower
the front attachment onto the ground.
W4GB-01-01-001
2. Stop the engine. Push valve (1) on hydraulic oil
tank (3) and release any remaining pressure.
3. Remove cap (2) on hydraulic oil tank (3).
1
4. Install a vacuum pump to the hole without cap (2).
Operate the vacuum pump and maintain negative
pressure in hydraulic oil tank (3).
NOTE: Run the vacuum pump continuously while
working.
2
3
W4GB-01-01-002
Vacuum Hose
Coupler
Coupler
Clamp
Inlet
Vacuum
Pump
Cover
Hydraulic oil
tank
Front
W4GB-01-04-001
W1-4-1
GENERAL / Bleed Air From Hydraulic Oil Tank
(Blank)
W1-4-2
MEMO
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SECTION 2
BODY (UPPERSTRUCTURE)
— CONTENTS —
Group 1 Cab
Group 7 Control Valve
Removal and Installation of Cab ................. W2-1-1
Group 2 Counterweight
Removal and Installation of
Counterweight ........................................... W2-2-1
Group 3 Center Hinge
Disassembly of Center Hinge ..................... W2-3-1
Assembly of Center Hinge .......................... W2-3-6
Group 4 Hood
Removal and Installation of Hood ............... W2-4-1
Group 5 Hydraulic Oil Tank
Removal and Installation of
Hydraulic Oil Tank ..................................... W2-5-1
Group 6 Pump Device
Removal and Installation of
Pump Device ............................................. W2-6-1
Removal and Installation of
Pilot Pump and Regulator ......................... W2-6-8
Disassembly of Main Pump ...................... W2-6-12
Assembly of Main Pump ........................... W2-6-14
Disassembly of Regulator ......................... W2-6-20
Assembly of Regulator.............................. W2-6-22
Disassembly of Priority Valve.................... W2-6-24
Assembly of Priority Valve ........................ W2-6-26
Structure of Pilot Pump ............................. W2-6-28
Maintenance Standard .............................. W2-6-30
Removal and Installation of Control Valve...W2-7-1
Disassembly of Control Valve......................W2-7-8
Assembly of Control Valve.........................W2-7-12
Group 8 Pilot Valve
Removal and Installation of Pilot Valve .......W2-8-1
Disassembly of Standard Pilot Valve for
Front Attachment .......................................W2-8-4
Assembly of Standard Pilot Valve for
Front Attachment .....................................W2-8-12
Maintenance Standard ..............................W2-8-20
Disassembly of Joy-Stick Type Pilot Valve
for Additional Circuit (Optional)................W2-8-22
Assembly of Joy-Stick Type Pilot Valve
for Additional Circuit (Optional)................W2-8-26
Disassembly of 2-Way Lever Type Pilot
Valve for Additional Circuit (Optional) ......W2-8-30
Assembly of 2-Way Lever Type
Pilot Valve for Additional Circuit...............W2-8-32
Group 9 Pilot Shut-Off Valve
Removal and Installation of
Pilot Shut-Off Valve....................................W2-9-1
Disassembly of Pilot Shut-Off Valve ............W2-9-4
Assembly of Pilot Shut-Off Valve.................W2-9-6
4HAW-2-1
Group 10 Hydraulic Fan Pump and Motor
Removal and Installation of
Hydraulic Fan Pump................................ W2-10-1
Removal and Installation of
Hydraulic Fan Motor................................ W2-10-3
Disassembly of Hydraulic Fan Pump........ W2-10-8
Assembly of Hydraulic Fan Pump........... W2-10-10
Hydraulic Fan Motor Standard ................ W2-10-14
4HAW-2-2
BODY (UPPERSTRUCTURE) / Cab
REMOVAL AND INSTALLATION OF CAB
2
Removal of Cab with Cockpit Attached
1. Remove sems bolts (2) (12 used) from covers (1)
(5 used). Remove covers (1) (5 used) from cockpit
(3).
: 17 mm
1
2
3
2
1
2
2
2
1
2
CAUTION: Hydraulic
pressure
is
accumulated in the hydraulic system by an
accumulator. Reduce pressure according to
the work point for each before disconnecting
the main, steering and brake system hoses.
2. Disconnect hose (5) between charging block (4)
and oil filter (6). Attach an identification tag onto
the disconnected hoses for assembling. Cap the
disconnected hoses.
: 22 mm, 27 mm
1
2
2
2
1
Front
W4GB-02-01-001
Front
4
Main Pump
5
6
3. Remove sems bolts (7) (2 used) from clamps (8)
(2 used). Disconnect hose (9) between charging
block (4) and return pipe (10). Disconnect hose
(12) between main pump (11) and charging block
(4).
: 14 mm, 17 mm, 22 mm, 27 mm
W4GB-02-01-002
Front
4
7
8
9
12
11
W2-1-1
10
W4GB-02-01-003
BODY (UPPERSTRUCTURE) / Cab
4. Remove sems bolts (17) (3 used) from clamps
(18) (3 used). Disconnect hose (19) between
charging block (4) and main pump (11).
Disconnect hoses (14, 16) between charging
block (4) and the rear side of hydraulic oil tank
(15).
: 14 mm, 17 mm
15
(Rear Side
of Hydraulic
Oil Tank)
Pilot Shut-Off Valve
4
14
16
17
18
19
11
W4GB-02-01-004
5. Disconnect hoses (21, 22) between pilot valve
(20) and main valve (23).
: 19 mm, 22 mm
20
21
22
W4GB-02-01-005
23
6. Disconnect hoses (25, 26) between steering pilot
valve (24) and stop valve (27).
: 19 mm, 22 mm
Front
Steering Valve
24
25
26
27
W2-1-2
W4GB-02-01-006
BODY (UPPERSTRUCTURE) / Cab
7. Remove sems bolts (29) (4 used) from clamps
(31) (4 used). Disconnect hose (30) between
steering pilot valve (28) and hydraulic oil tank (15).
: 17 mm, 22 mm, 27 mm
15
Front
30
31
29
28
29
Charging Block
29
8. Remove sems bolts (38) (4 used) from clamps
(37) (4 used). Disconnect hose (33) between
brake valve (39) and front axle (32). Disconnect
hose (35) between brake valve (39) and suction
tube (34). Disconnect hose (36) between brake
valve (39) and the rear axle.
: 19 mm, 22 mm, 27 mm
W4GB-02-01-007
33
32
34
35
36
39
To Rear
Axle
37, 38
W4GB-02-01-008
9. Disconnect hose (40) between charging block (4)
and parking brake (41) in the transmission.
: 17 mm
4
40
41
Transmission
W4GB-02-01-009
W2-1-3
BODY (UPPERSTRUCTURE) / Cab
10. Remove bolt (43) for terminal minus from battery
(42) either left or right side. Disconnect battery
cable (44).
: 12 mm
42
44
11. Disconnect connectors (45, 46) of the wire
harness under the cab.
43
W4GB-02-01-010
45
46
W4GB-02-01-011
CAUTION: This machine uses new freon
R134a as refrigerant. Recover all the
refrigerants. Do not release them into the
atmosphere.
12. Disconnect refrigerant hoses (49, 50) attached to
the lower of cockpit (3).
: 17 mm, 19 mm, 24 mm, 27 mm
Front
3
13. Drain off coolant from the radiator. Disconnect the
hose from heater pipings (47, 48).
47
48
49
50
W4GB-02-01-012
W2-1-4
BODY (UPPERSTRUCTURE) / Cab
14. Remove caps (51) (4 used) and plates (52) (4
used) with the packing attached from the top of
cab (53). Install eyebolts (M16, Pitch 2.0 mm) (4
used) to cab (53).
51
Front
52
53
15. Remove bolts (54, 63) (2 used for each), nuts (60)
(2 used) nuts, (57) (4 used), plates (59, 62) (2
used for each), spacers (58, 61) (2 used for each)
and washers (56) (8 used) which secure cockpit
(3) and frame (55).
: 17 mm, 30 mm
W4GB-02-01-013
3
54
55
61
62
56
57
CAUTION: Cab (53) Weight:
1145 kg (2550 lb)
16. Attach a nylon sling onto the eyebolt on the top of
cab (53). Hoist and remove cab (53) from the
cockpit.
58
59
56
60
57
63
W4GB-02-01-014
53
W4GB-02-01-015
W2-1-5
BODY (UPPERSTRUCTURE) / Cab
Installation of Cab
CAUTION: Cab (53) Weight:
1145 kg (2550 lb)
1. Attach a nylon sling onto an eyebolt on the top of
cab (53). Hoist and align cab (53) with the holes
on the cockpit.
53
2. Install cockpit (3) to frame (55) with bolts (54, 63)
(2 used for each), nuts (60) (2 used) nuts, (57) (4
used), plates (59, 62) (2 used for each), spacers
(58, 61) (2 used for each) and washers (56) (8
used). At this time, install washer (56) between
the cockpit mount and frame (55).
: 17 mm
: 50 N⋅m (5 kgf⋅m, 36 lbf·ft)
: 30 mm
: 137 N⋅m (14 kgf⋅m, 101 lbf·ft)
W4GB-02-01-015
3
54
55
58
61
Cockpit Mount
62
56
57
3. Remove eyebolts (4 used) from the top of cab (53).
Install caps (51) (4 used) and plates (52) (4 used)
with the packing attached to cab (53).
Front
59
56
60
57
63
W4GB-02-01-014
51
52
53
W4GB-02-01-013
W2-1-6
BODY (UPPERSTRUCTURE) / Cab
4. Connect hoses (49, 50) under cockpit (3).
Connect heater pipings (47, 48).
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
: 19 mm
: 29.4 N⋅m (3 kgf⋅m, 21.5 lbf·ft)
: 24 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
: 27 mm
: 78 N⋅m (8 kgf⋅m, 57.5 lbf·ft)
Front
3
5. This machine uses new freon R134a as
refrigerant. Check for any gas leakage after
injecting gas for the required amount.
Type
HFC
Refrigerant
Number
R134a
47
Q’ty
kg (lb)
1.05±0.05
(2.32±0.11)
48
49
50
W4GB-02-01-012
6. Connect connectors (45, 46) of the wire harness
under the cab.
45
46
W4GB-02-01-011
7. Connect battery cable (44) to terminal minus of
battery (42) with bolt (43).
: 12 mm
: 10 N⋅m (1 kgf⋅m, 7.2 lbf·ft)
42
44
43
W4GB-02-01-010
W2-1-7
BODY (UPPERSTRUCTURE) / Cab
8. Connect hose (40) between charging block (4)
and parking brake (41) in the transmission.
: 17 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
4
40
41
Transmission
9. Connect hose (33) between brake valve (39) and
front axle (32). Connect hose (35) between brake
valve (39) and suction tube (34). Connect hose
(36) between brake valve (39) and the rear axle.
Secure clamps (37) (4 used) to the frame with
sems bolts (38) (4 used).
: 19 mm
: 29.5 N⋅m (3 kgf⋅m, 21.5 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
: 27 mm
: 78 N⋅m (8 kgf⋅m, 57.5 lbf·ft)
W4GB-02-01-009
33
32
34
35
36
39
To Rear
Axle
37, 38
W4GB-02-01-008
10. Connect hose (30) between steering pilot valve
(28) and hydraulic oil tank (15). Secure clamps
(31) (4 used) to the frame with sems bolts (29) (4
used).
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
: 27 mm
: 78 N⋅m (8 kgf⋅m, 57.5 lbf·ft)
15
Front
30
29
25
31
29
Charging Block
29
W2-1-8
W4GB-02-01-007
BODY (UPPERSTRUCTURE) / Cab
11. Connect hoses (25, 26) between steering pilot
valve (24) and stop valve (27).
: 19 mm
: 29.5 N⋅m (3 kgf⋅m, 21.5 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
Front
Steering Valve
24
25
26
27
12. Connect hoses (21, 22) between pilot valve (20)
and main valve (23).
: 19 mm
: 29.5 N⋅m (3 kgf⋅m, 21.5 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
W4GB-02-01-006
21
20
22
W4GB-02-01-005
23
13. Connect hose (19) between charging block (4)
and main pump (11). Connect hoses (14, 16)
between charging block (4) and the rear side of
hydraulic oil tank (15).
Secure clamps (18) (3 used) to the frame with
sems bolts (17) (3 used).
: 14 mm
: 20 N⋅m (2 kgf⋅m, 14.5 lbf·ft)
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
Pilot Shut-Off Valve
14
15
Rear Side
of Hydraulic
Oil Tank
4
16
17
18
19
11
W4GB-02-01-004
W2-1-9
BODY (UPPERSTRUCTURE) / Cab
14. Connect hose (9) between charging block (4) and
return pipe (10). Secure clamps (8) (2 used) to the
frame with sems bolts (7) (2 used). Connect hose
(12) between main pump (11) and charging block
(4).
: 14 mm
: 20 N⋅m (2 kgf⋅m, 14.5 lbf·ft)
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
: 27 mm
: 78 N⋅m (8 kgf⋅m, 57.5 lbf·ft)
4
Front
7
8
9
12
11
W4GB-02-01-003
10
15. Connect hose (5) between charging block (4) and
oil filter (6).
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
: 27 mm
: 78 N⋅m (8 kgf⋅m, 57.5 lbf·ft)
4
Front
Main Pump
5
6
W4GB-02-01-002
16. Add coolant to the radiator. Start the engine and
the test run.
Check for any oil leakage at the hose connections.
CAUTION: Wear safety goggles and gloves
when checking oil leaks. Apply cardboard or
laminated wood at the check point.
High-pressure oil may cause serious injury to
the skin and eyes.
W2-1-10
BODY (UPPERSTRUCTURE) / Cab
17. Install covers (1) (5 used) to cockpit (3) with sems
bolts (2) (12 used).
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
2
1
2
3
2
1
2
2
2
1
2
2
1
2
2
1
Front
W4GB-02-01-001
W2-1-11
BODY (UPPERSTRUCTURE) / Cab
(Blank)
W2-1-12
BODY (UPPERSTRUCTURE) / Counterweight
REMOVAL AND INSTALLATION OF
COUNTERWEIGHT
Removal
Lifting Tool
CAUTION: Counterweight weight:
1810 kg (4000 lb)
CAUTION: 1. Park the machine on a flat
place and stop the engine.
2. Put a chock and apply the
parking brake in order not to
move the machine.
3. Lower the bucket onto the
ground.
Release
hydraulic
pressure in the hydraulic
device.
1
2
3
1. Open the rear grill.
CAUTION: When removing counterweight (3)
with the rear grill closed, the rear grill may be
damaged.
4
6
5
2. Install a lifting tool to counterweight (3). Hoist
counterweight (3) a little.
CAUTION: When hoisting counterweight (3)
too much, it difficult to remove bolt (5) and
the screw part may be damaged.
3. Remove nuts (1) (2 used) and washers (2) (2
used).
: 46 mm
4. Loosen bolts (5) (4 used). Remove bolts (5) (4
used) and washers (4) (4 used) from
counterweight (3) while finely adjusting the hoist
of counterweight (3).
: 46 mm
5. Move counterweight (3) to the rear side of frame
(6) and remove counterweight (3).
W2-2-1
W4GB-02-02-001
BODY (UPPERSTRUCTURE) / Counterweight
Installation
CAUTION: Counterweight weight:
1810 kg (4000 lb)
Lifting Tool
1. Hoist counterweight (3) by using a lifting tool.
Move counterweight (3) to about 200 mm (8 in) in
front of the counterweight (3) mounting part of
frame (6).
1
2. Align the screw holes on counterweight (3) and
frame (6). Place counterweight (3) onto frame (6).
2
3. Install counterweight (3) to frame (6) with blots (5)
(4 used) and washers (4) (4 used).
: 46 mm
: 1510 N⋅m (154 kgf⋅m, 1110 lbf·ft)
4. Install nuts (1) (2 used) and washers (2) (2 used)
to bolts (5) (2 used) on the upper side.
: 46 mm
: 1510 N⋅m (154 kgf⋅m, 1110 lbf·ft)
3
4
5
6
W4GB-02-02-001
W2-2-2
BODY (UPPERSTRUCTURE) / Center Hinge
DISASSEMBLY OF CENTER HINGE
2
3
1
1
4
5
6
7
8
9
10
11
12
13
24
14
15
16
17
25
18
8
24
23
18
19
10
9
15
20
21
22
W4GB-02-03-021
1234567-
Washer (10 Used)
Bolt (4 Used)
Bolt (6 Used)
Flange
Shim (2 Used)
Bushing
Cap
8 - Shim (2 Used)
9 - Dust Seal (2 Used)
10 - Bearing (2 Used)
11 - Bolt
12 - Washer
13 - Washer
14 - Pin
15 - Bushing (2 Used)
16 - Bolt (6 Used)
17 - Cap
18 - Dust Seal (2 Used)
19 - Cap
W2-3-1
20 - Bushing
21 - Bolt (6 Used)
22 - Pin
23 - Cap
24 - Grease Fitting (2 Used)
25 - Front Frame
BODY (UPPERSTRUCTURE) / Center Hinge
2
3
4
5
6
7
8
9
10
11
12
13
14
25
19
9
20
21
22
W4GB-02-03-021
W2-3-2
BODY (UPPERSTRUCTURE) / Center Hinge
Disassembly of Center Hinge
CAUTION: The center hinge is required to
disassemble for the major maintenance work
such as removal of the front frame from the
rear frame. At this time, move the machine
into the factory.
Preparation
Carry out the following procedures
disassembling the center hinge.
before
1. Remove the cab and the cockpit.
2. Remove the mounting component between the
front frame and the rear frame.
• Propeller Shaft
• Steering Cylinder
• Hydraulic Hose
• Brake Piping
• Wire Harness
Removal of Hinge Pin
1. Support the front frame and the rear frame by
using firm support stands.
2. Remove bolts (2) (4 used) and bolts (3) (6 used)
from flange (4) of the upper hinge part. Remove
flange (4), shims (5) (2 used) and pin (22) from
front frame (25).
: 24 mm
3. Remove bolt (11) and washers (12, 13) from pin
(14). Remove pin (14) from front frame (25).
: 24 mm
4. Remove bushing (6) from front frame (25).
(Remove bushing (6) after cutting by gas or
pulling out by welding a cardboard.)
CAUTION: Front frame (25) weight:
2080 kg (4600 lb)
5. Attach a nylon sling onto front frame (25). Hoist
and move front frame (25) so that bearing (10)
can be removed.
6. Remove bushing (20) from front frame (25).
7. Remove bolts (21) (6 used) from cap (19).
Remove caps (7, 19) and shim (8) from front
frame (25).
: 24 mm
8. Remove dust seals (9) (2 used) from caps (7, 19).
9. Remove bearing (10) from front frame (25).
W4GB-02-03-002
W2-3-3
BODY (UPPERSTRUCTURE) / Center Hinge
16
15
17
25
18
8
23
18
10
15
W4GB-02-03-021
W2-3-4
BODY (UPPERSTRUCTURE) / Center Hinge
10. Remove bolts (16) (6 used) from cap (17).
Remove caps (17, 23) and shim (8) from front
frame (25).
: 17 mm
11. Remove dust seals (18) (2 used) from caps (17,
23).
12. Remove bearing (10) from front frame (25).
13. Remove bushings (15) (2 used) from the lower
hinge part of the rear frame.
W2-3-5
BODY (UPPERSTRUCTURE) / Center Hinge
ASSEMBLY OF CENTER HINGE
Upper Hinge
1, 3
1, 2
4
6
5
9
7
8
25
24
10
19
20
22
9
21
W4GB-02-03-003
Lower Hinge Pin
11, 12, 13
18
15
16
17
8
25
24
23
10
18
15
14
W4GB-02-03-004
1234567-
Washer (10 Used)
Bolt (4 Used)
Bolt (6 Used)
Flange
Shim (2 Used)
Bushing
Cap
8 - Shim (2 Used)
9 - Dust Seal (2 Used)
10 - Bearing (2 Used)
11 - Bolt
12 - Washer
13 - Washer
14 - Pin
15 - Bushing (2 Used)
16 - Bolt (6 Used)
17 - Cap
18 - Dust Seal (2 Used)
19 - Cap
W2-3-6
20 - Bushing
21 - Bolt (6 Used)
22 - Pin
23 - Cap
24 - Grease Fitting (2 Used)
25 - Front Frame
BODY (UPPERSTRUCTURE) / Center Hinge
Assembly of Center Hinge
1. Continuously apply LOCTITE #262 onto the outer
circumference of dust seal (18). Lightly tap and
insert dust seal (18) into cap (17) by using a
hammer. Wipe out the stick-out LOCTITE #262 by
using a waste.
Install dust seal (18) to cap (23) in the same way.
IMPORTANT: Check the direction of dust seal (18).
Install dust seal (18) with the wider
rubber side facing to the unpainted
side of caps (17, 23).
17, 23
18
Face the lip to the outer side
(painted side of the cap)
W4GB-02-03-005
2. Insert dust seals (9) (2 used) into caps (7, 19) in
the same way.
6. Install caps (7, 19) and shim (8) to the upper
hinge part of front frame (25). Apply LOCTITE
#262 onto bolts (21) (6 used). Install caps (7, 19)
to front frame (25) with bolts (21) (6 used).
: 24 mm
: 224 N⋅m (23 kgf⋅m, 165 lbf·ft)
7. Tap the space among caps (7, 19) and dust seals
(9) (2 used) by using an iron nail.
8. Install caps (17, 23) and shim (8) to the lower
hinge part of front frame (25). Apply LOCTITE
#262 onto bolts (16) (6 used). Install caps (17, 23)
to front frame (25) with bolts (16) (6 used).
: 17 mm
: 88 N⋅m (9 kgf⋅m, 65 lbf·ft)
9. Tap the space among caps (17, 23) and dust
seals (18) (2 used) by using an iron nail.
3. Insert bearing (10) into the upper hinge part of
front frame (25).
4. Add grease through grease fitting (24) into the
inside of bearing (10) while rotating bearing (10).
5. Insert bearing (10) into the lower hinge part of
front frame (25). Add grease through grease
fitting (24).
W2-3-7
BODY (UPPERSTRUCTURE) / Center Hinge
Upper Hinge
1, 3
1, 2
4
6
5
25
20
22
W4GB-02-03-003
Lower Hinge Pin
11, 12, 13
15
25
15
14
W4GB-02-03-004
W2-3-8
BODY (UPPERSTRUCTURE) / Center Hinge
10. Insert bushings (15) (2 used) into the lower hinge
part of the rear frame.
CAUTION: Front frame (25) weight:
2080 kg (4600 lb)
11. Attach a nylon sling onto front frame (25). Hoist
and align front frame (25) with the center hinge
pin holes on the rear frame.
12. Install pin (22), bushings (6, 20), shims (5) (2
used) and flange (4) to the upper hinge part.
Tighten bolts (2) (4 used), bolts (3) (6 used) and
washers (1) (10 used).
: 24 mm
: 224 N⋅m (23 kgf⋅m, 165 lbf·ft)
13. Insert pin (14) into the lower hinge part. Tighten
bolt (11) and washers (12, 13).
: 24 mm (0.94 in)
: 86.9 N⋅m (8.9 kgf⋅m, 64 lbf·ft)
W2-3-9
BODY (UPPERSTRUCTURE) / Center Hinge
(Blank)
W2-3-10
BODY (UPPERSTRUCTURE) / Hood
REMOVAL AND INSTALLATION OF HOOD
Removal
1. Open the left and right side covers.
2. Loosen hose bands (3) (2 used) which secure
intake hose (4). Disconnect intake hose (4) from
pipe (2) and the engine.
1
3. Disconnect the harness for sensor (1) at the
connector part.
CAUTION: The hood (5) assembly weight:
159 kg (350 lb)
2
4. Attach a nylon sling onto hood (5). Hoist and hold
hood (5). Remove bolts (7) (4 used) and washers
(6) (4 used) from hood (5). Hoist and remove hood
(5) from the frame.
Air Cleaner
: 17 mm
3
Installation
CAUTION: The hood (5) assembly weight:
159 kg (350 lb)
1. Attach a nylon sling onto hood (5). Hoist hood (5).
Align the exhaust pipe and the vent of the muffler.
Install hood (5) to the frame with bolts (7) (4 used)
and washers (6) (4 used).
: 17 mm
: 50 N⋅m (5 kgf⋅m, 36 lbf·ft)
4
W4GB-02-03-007
5
2. Connect the harness for sensor (1) at the
connector part.
3. Connect intake hose (4) to the engine and pipe (2).
Secure intake hose (4) with hose bands (3) (2 used).
4. Shut the left and right side covers.
6
7
W4GB-02-03-006
W2-4-1
BODY (UPPERSTRUCTURE) / Hood
(Blank)
W2-4-2
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
REMOVAL
AND
INSTALLATION
HYDRAULIC OIL TANK
OF
1
2
CAUTION: Hydraulic oil tank (5) weight:
215 kg (475 lb)
3
Removal
1. Remove the hood. (Refer to W2-4-1.)
4
5
2. Remove the left and right side fenders.
: 17 mm
3. Remove bolts (1) (6 used) and washers (2) (6
used) from cover (3). Remove cover (3) and
suction filter (4) from hydraulic oil tank (5).
: 14 mm
4. Drain hydraulic oil from the suction filter mounting
part of hydraulic oil tank (5) by using a pump.
CAUTION: Drain hydraulic oil from the
suction pipe at the bottom of hydraulic oil
tank (5).
CAUTION: Attach an identification tag onto
each hose connected to hydraulic oil tank (5)
for assembling.
W4GB-02-03-010
6
5
5. Disconnect hose (6) from hydraulic oil tank (5).
: 22 mm
6. Disconnect hose (8) and remove O-ring (7) from
hydraulic oil tank (5).
: 36 mm
CAUTION: O-ring (7) cannot be reused.
7. Loosen hose clamps (9) (2 used). Disconnect
hose (10) from hydraulic oil tank (5) and pipe (11).
9
7
8
10
9
11
W4GB-02-03-011
W2-5-1
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
8. Loosen hose clamps (12) (2 used). Disconnect
hose (13) from hydraulic oil tank (5) and pipe (15).
9. Disconnect hose (14) from hydraulic oil tank (5).
: 27 mm
5
12
13
12
14
15
W4GB-02-03-012
5
10. Disconnect hoses (16, 17) from hydraulic oil tank
(5).
: 17 mm
16
17
W4GB-02-03-013
W2-5-2
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
11. Disconnect hoses (18, 19) from block (20) when
the emergency steering pump is installed.
: 17 mm, 22 mm
18
19
20
W4GB-02-03-014
12. Disconnect the connector from hydraulic oil
temperature sensor (23) and level sensor (24).
5
13. Remove bolts (22) (8 used) from clamps (21) (8
used). Disconnect wire harness (25) from
hydraulic oil tank (5).
：12 mm
21, 22
24
23
25
21, 22
21, 22
W4GB-02-03-017
W2-5-3
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
CAUTION: Hydraulic oil tank (5) weight:
215 kg (475 lb)
5
14. Attach a nylon sling onto hydraulic oil tank (5).
Hoist and hold hydraulic oil tank (5). Remove bolts
(26) (6 used) and washers (27) (6 used) from
hydraulic oil tank (5).
: 24 mm
15. Hoist and remove hydraulic oil tank (5) from the
frame.
26
27
26
27
W4GB-02-03-016
W2-5-4
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
Installation
5
CAUTION: Hydraulic oil tank (5) weight:
215 kg (475 lb)
1. Attach a nylon sling onto hydraulic oil tank (5).
Hoist and align hydraulic oil tank (5) with the
mounting position of the frame.
2. Install hydraulic oil tank (5) to the frame with bolts
(26) (6 used) and washers (27) (6 used).
: 24 mm
: 210 N⋅m (21.5 kgf⋅m, 152 lbf·ft)
26
27
26
27
3. Connect hoses (18, 19) to block (20) as shown in
the identification tag when the emergency steering
pump is installed.
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
W4GB-02-03-016
18
19
20
W4GB-02-03-014
W2-5-5
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
4. Connect hoses (16, 17) to hydraulic oil tank (5).
: 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
5
16
17
W4GB-02-03-013
5. Connect hose (14) to hydraulic oil tank (5).
: 27 mm
: 93 N⋅m (9.5 kgf⋅m, 68.5 lbf·ft)
6. Connect hose (13) to hydraulic oil tank (5) and
pipe (15). Secure hose (13) with hose clamps (12)
(2 used).
5
12
13
12
14
15
W4GB-02-03-012
W2-5-6
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
7. Connect hose (10) to hydraulic oil tank (5) and
pipe (11). Secure hose (10) with hose clamps (9)
(2 used).
5
6
8. Install hydraulic oil tank (5) and new O-ring (7),
and connect hose (8).
: 36 mm
: 175 N⋅m (18 kgf⋅m, 129 lbf·ft)
9. Connect hose (6) to hydraulic oil tank (5).
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
10. Add hydraulic oil to hydraulic oil tank (5).
Hydraulic oil amount: 120 L (31.7 US gal.)
7
9
8
10
9
11
W4GB-02-03-011
11. Install suction filter (4) to hydraulic oil tank (5).
12. Install cover (3) to hydraulic oil tank (5) with bolts
(1) (6 used) and washers (2) (6 used).
: 14 mm
: 20 N⋅m (2 kgf⋅m, 14.5 lbf·ft)
1
2
3
4
5
W4GB-02-03-010
W2-5-7
BODY (UPPERSTRUCTURE) / Hydraulic Oil Tank
13. Connect wire harness (25) to hydraulic oil tank (5)
with bolts (22) (8 used) and clamps (21) (8 used).
: 12 mm
: 20 N⋅m (2 kgf⋅m, 14.5 lbf·ft)
5
14. Connect the connectors of level sensor (24) and
hydraulic oil temperature sensor (23).
21, 22
24
15. Install the left and right side fenders.
: 17 mm
: 50 N⋅m (5.1 kgf⋅m, 36 lbf·ft)
23
25
16. Install the hood. (Refer to W2-4-1.)
21, 22
21, 22
W4GB-02-03-017
W2-5-8
BODY (UPPERSTRUCTURE) / Pump Device
REMOVAL AND INSTALLATION OF PUMP
DEVICE
Main Pump
Regulator
Removal
1. Remove the cab with the cockpit attached.
(Refer to REMOVAL AND INSTALLATION OF
CAB in W2-1.)
Priority Valve
CAUTION: Pump device weight:
108 kg (240 lb)
Pilot Pump
2. Remove sems bolts (1) (6 used) from hydraulic oil
tank (4). Remove cover (2) and suction filter (3)
from hydraulic oil tank (4). Drain hydraulic oil.
: 14 mm
Pump Delivery
T4GB-01-02-009
Pressure Switch
1
2
3
4
W4GB-02-03-010
3. Disconnect hoses (5) (2 used) from main pump
(6). Cap the open ends. Attach an identification
tag onto the disconnected hoses for assembling.
: 19 mm, 22 mm
5
6
Control Valve
W4GB-02-04-012
W2-6-1
BODY (UPPERSTRUCTURE) / Pump Device
4. Disconnect hose (7) from main pump (6). Cap the
open ends. Remove socket bolts (8) (4 used)
from pipe (9). Disconnect pipe (9) from main
pump (6).
: 32 mm, 36 mm
: 10 mm
7
8
6
9
5. Disconnect hose (11) from main pump (6).
Disconnect hose (12) from priority valve (10). Cap
the open ends.
: 36 mm, 41 mm
W4GB-02-04-019
Steering Valve
6
10
11
12
W4GB-02-04-014
Steering Valve
6. Disconnect hose (13) from priority valve (10). Cap
the open ends.
: 14 mm, 17 mm
10
13
W2-6-2
W4GB-02-04-015
BODY (UPPERSTRUCTURE) / Pump Device
7. Disconnect hoses (15, 16) from pilot pump (14).
Cap the open ends.
: 27 mm, 36 mm
14
15
16
W4GB-02-04-018
8. Disconnect the connector of pump delivery
pressure switch (17) under priority valve (10).
10
17
W4GB-02-04-016
9. Remove socket bolts (18) (2 used) from pilot
pump (14). Remove pilot pump (14) from main
pump (6).
Remove reducer (20) from the regulator. Install
plug (19) (with an eyebolt attached) (screw size
G1, wrench size 41 mm) to the regulator.
: 8 mm
: 41 mm
10. Attach a nylon sling onto the eyebolt. Hoist and
hold main pump (6). Remove socket bolts (21) (4
used) from main pump (6). Hoist and remove
main pump (6) from the engine.
: 10 mm
19
20
14
18
6
21
W4GB-02-04-017
W2-6-3
BODY (UPPERSTRUCTURE) / Pump Device
Installation
1. Attach a nylon sling onto plug (19) (with an
eyebolt attached). Hoist and align main pump (6)
with the mounting hole on the engine. Install main
pump (6) to the engine with socket bolts (21) (4
used). Remove plug (19) from the regulator.
Install reducer (20). Install pilot pump (14) to main
pump (6) with socket bolts (18) (2 used).
: 8 mm
: 50 N⋅m (5 kgf⋅m, 36 lbf·ft)
: 10 mm
: 90 N⋅m (9 kgf⋅m, 65 lbf·ft)
: 41 mm
: 81 N⋅m (8 kgf⋅m, 59.5 lbf·ft)
2. Connect the connector of pump delivery pressure
switch (17) under the priority valve (10).
19
20
14
18
6
21
W4GB-02-04-017
10
17
W4GB-02-04-016
3. Connect hoses (15, 16) to pilot pump (14).
: 27 mm
: 78 N⋅m (8 kgf⋅m, 58 lbf·ft)
: 36 mm
: 175 N⋅m (18 kgf⋅m, 129 lbf·ft)
14
15
16
W4GB-02-04-018
W2-6-4
BODY (UPPERSTRUCTURE) / Pump Device
4. Connect hose (13) to priority valve (10).
: 14 mm, 17 mm
: 24.5 N⋅m (2.5 kgf⋅m, 18 lbf·ft)
Steering Valve
10
13
W4GB-02-04-015
5. Connect hose (12) to priority valve (10). Connect
hose (11) to main pump (6).
: 36 mm
: 175 N⋅m (18 kgf⋅m, 129 lbf·ft)
: 41 mm
: 205 N⋅m (21 kgf⋅m, 151 lbf·ft)
Steering Valve
6
10
11
12
W4GB-02-04-014
6. Connect hose (7) to main pump (6). Install bolts
(8) (4 used) of pipe (9).
: 32 mm
: 137 N⋅m (14 kgf⋅m, 101 lbf·ft)
: 36 mm
: 175 N⋅m (18 kgf⋅m, 129 lbf·ft)
7. Connect pipe (9) to main pump (6) with socket
bolts (8) (4 used).
: 10 mm
: 90 N⋅m (9 kgf⋅m, 65 lbf·ft)
7
8
6
9
W4GB-02-04-019
W2-6-5
BODY (UPPERSTRUCTURE) / Pump Device
8. Connect hoses (5) (2 used) to main pump (6).
: 19 mm
: 29.5 N⋅m (3 kgf⋅m, 21.5 lbf·ft)
: 22 mm
: 39 N⋅m (4 kgf⋅m, 28.5 lbf·ft)
5
6
Control Valve
W4GB-02-04-012
9. Install suction filter (3) to hydraulic oil tank (4).
Add hydraulic oil to hydraulic oil tank (4). Install
cover (2) to hydraulic oil tank (4) with sems bolts
(1) (6 used).
After filling hydraulic oil tank (4) with hydraulic oil,
loosen the bleeder valve in the regulator and
bleed air.
: 14 mm
: 15 N⋅m (1.5 kgf⋅m, 11 lbf·ft)
1
2
3
4
10. Install the cab with the cockpit attached.
(Refer to REMOVAL AND INSTALLATION OF
CAB in W2-1.)
W4GB-02-03-010
W2-6-6
BODY (UPPERSTRUCTURE) / Pump Device
(Blank)
W2-6-7
BODY (UPPERSTRUCTURE) / Pump Device
REMOVAL AND INSTALLATION OF PILOT PUMP AND REGULATOR
6
7
8
Reducer
1
1 - Pilot Pump
2 - Socket Bolt (2 Used)
4
T4GB-03-01-001
2
3
5
34-
Spring Washer (2 Used)
Washer (2 Used)
56-
W2-6-8
O-Ring
Regulator
78-
Socket Bolt (4 Used)
Main Pump
BODY (UPPERSTRUCTURE) / Pump Device
Removal
CAUTION: Pump device weight:
108 kg (240 lb)
1. Remove the reducer (with the bleeder valve
attached) at the regulator part of the pump device.
Install the plug (with an eyebolt attached). Attach
a nylon sling onto the eyebolt. Hoist the pump
device. Place the pump device onto a wooden
block of approximately 100 mm square (3.9 in
square) with the regulator facing upward.
: 41 mm
IMPORTANT: Pay attention to the removal and
installation of O-ring between
regulator (6) and main pump (8).
4. Remove regulator (6) from main pump (8).
NOTE: Pull the regulator obliquely upward when it
floats up. Refer to W2-6-8.
W4GB-02-04-001
2. Remove socket bolts (2) (2 used), spring washers
(3) (2 used) and washers (4) (2 used) from pilot
pump (1). Remove pilot pump (1) and O-ring (5)
from main pump (8).
: 8 mm
3. Remove socket bolts (7) (4 used) from regulator
(6).
: 8 mm
W2-6-9
BODY (UPPERSTRUCTURE) / Pump Device
6
7
8
1
2
3
4
T4GB-03-01-001
5
W2-6-10
BODY (UPPERSTRUCTURE) / Pump Device
Installation
IMPORTANT: Check that five O-rings are attached
on the regulator mounting surface.
1. Install regulator (6) to main pump (8) in the
following procedures.
• Adjust the two sleeve positions and align two
grooves in both sleeves on regulator (6).
• Place regulator (6) on main pump (8). Insert the
feedback link pins into two grooves in both
sleeves.
• Move regulator (6) so that two knock pins
extended from main pump (8) can enter regulator
(6).
• Install regulator (6) to main pump (8) with socket
bolts (7) (4 used).
: 8 mm
: 50 N⋅m (5 kgf⋅m, 36 lbf·ft)
Feedback
Link
6
Pin
Knock Pin O-Ring
7
8
W4GB-02-04-002
2. Install O-ring (5) to pilot pump (1).
IMPORTANT: Place pilot pump (1) with the inlet
port (the larger port diameter) facing
upward.
3. Install pilot pump (1) to main pump (8) with socket
bolts (2) (2 used), spring washers (3) (2 used) and
washers (4) (2 used).
: 8 mm (0.31 in)
: 50 N⋅m (5 kgf⋅m, 36 lbf·ft)
W2-6-11
BODY (UPPERSTRUCTURE) / Pump Device
DISASSEMBLY OF MAIN PUMP
1
2
3
4
5
6
7
8
9
10
23 24
25
26
27 28
29
30
31
11
12
21
13
14
15 16 17
38
18
19 20 21
22
39
41
40
23
32
43
33
44
34
35
36 37
45
Detail for Position A
42
W4GB-02-04-003
1 - Retaining Ring
2 - Pump Casing
3 - Valve Plate
4 - Rotor
5 - Plunger (9 Used)
6 - Swash Plate
7 - Knock Pin
8 - Front Casing
9 - Socket Bolt (8 Used)
10 - Socket Bolt (4 Used)
11 - Drive Shaft
12 - Inner Race
13 - Needle Bearing
14 - Knock Pin
15 - Spring (4 Used)
16 - Bushing
17 - Servo Piston (3 Used)
18 - Retainer
19 - Cam Plate
20 - Knock Pin
21 - Plug
22 - Cradle Plate
23 - Plug
24 - Pin
25 - Spring Pin
26 - Feedback Link
27 - Spring Pin
28 - Pin
29 - Link pin
30 - O-Ring
31 - O-Ring
32 - Retaining Ring (2 Used)
33 - Plug
34 - Roller Bearing
W2-6-12
35 - Knock Pin
36 - Oil Seal
37 - Retaining Ring
38 - O-Ring
39 - Spring Pin (2 Used)
40 - O-Ring (5 Used)
41 - Plug
42 - Pressure Sensor
43 - Restrictor Pin
44 - Backup Ring (2 Used)
45 - O-Ring (2 Used)
BODY (UPPERSTRUCTURE) / Pump Device
Disassembly of Main Pump
CAUTION: Pump device weight:
108 kg (240 lb)
1. Secure the pump device on a workbench with the
pilot pump side facing downward.
CAUTION: Front casing (8) weight:
48 kg (110 lb)
2. Remove socket bolts (9) (8 used) from front
casing (8).
: 14 mm
IMPORTANT: Inner race (12) with drive shaft (11)
attached cannot be replaced. Do not
damage inner race (12).
3. Remove the front casing (8) assembly from pump
casing (2). At this time, drive shaft (11), the rotor
(4) assembly and restrictor pin (43) are removed
with front casing (8) together.
NOTE: When removing front casing (8), raise the
pump casing (2) side a little in order to
prevent rotor (4) from falling off.
NOTE: Do not remove restrictor pin (43) unless
necessary.
Restrictor pin (43) may stay in pump casing
(2).
4. Place front casing (8) onto a wooden block of
more than 30 mm square (1.2 in square) with the
rotor (4) side facing upward.
IMPORTANT: The valve plate (3) side of rotor (4) is
a sliding surface. Do not damage the
sliding surface.
5. Put a hand on retainer (18) and remove the rotor
(4) assembly from drive shaft (11). Place the rotor
(4) assembly with the valve plate side facing
downward.
6. Put a hand under retainer (18) and remove
retainer (18) with servo piston (17) together from
rotor (4).
7. Remove bushing (16) and springs (15) (4 used)
from rotor (4).
8. Remove plate (19) from swash plate (6).
NOTE: By tapping the yoke part with plate (19)
facing upward, plate (19) is floated.
9. Remove socket bolts (10) (4 used) from cradle
plate (22). Remove cradle plate (22) from front
casing (8).
: 6 mm
10. Remove drive shaft (11) with roller bearing (34)
together from front casing (8) by hands.
IMPORTANT: When removing retaining ring (32),
do not damage the seal lip surface of
drive shaft (11).
11. Remove retaining rings (32) (2 used) from drive
shaft (11).
12. Remove the roller and the outer ring of roller
bearing (34).
W2-6-13
BODY (UPPERSTRUCTURE) / Pump Device
ASSEMBLY OF MAIN PUMP
1
2
3
4
5
6
7
8
9
10
23 24
25
26
27 28
29
30
31
11
12
21
13
14
15 16 17
38
18
19 20 21
22
39
41
40
23
32
43
33
44
34
35
36 37
45
Detail for Position A
42
W4GB-02-04-003
1 - Retaining Ring
2 - Pump Casing
3 - Valve Plate
4 - Rotor
5 - Plunger (9 Used)
6 - Swash Plate
7 - Knock Pin
8 - Front Casing
9 - Socket Bolt (8 Used)
10 - Socket Bolt (4 Used)
11 - Drive Shaft
12 - Inner Race
13 - Needle Bearing
14 - Knock Pin
15 - Spring (4 Used)
16 - Bushing
17 - Servo Piston (3 Used)
18 - Retainer
19 - Cam Plate
20 - Knock Pin
21 - Plug
22 - Cradle Plate
23 - Plug
24 - Pin
25 - Spring Pin
26 - Feedback Link
27 - Spring Pin
28 - Pin
29 - Link pin
30 - O-Ring
31 - O-Ring
32 - Retaining Ring (2 Used)
33 - Plug
34 - Roller Bearing
W2-6-14
35 - Knock Pin
36 - Oil Seal
37 - Retaining Ring
38 - O-Ring
39 - Spring Pin (2 Used)
40 - O-Ring (5 Used)
41 - Plug
42 - Pressure Sensor
43 - Restrictor Pin
44 - Backup Ring (2 Used)
45 - O-Ring (2 Used)
BODY (UPPERSTRUCTURE) / Pump Device
Assembly of Main Pump
1. Tap and install needle bearing (13) with the
stamped mark on the outer race facing upward to
pump casing (2) by using a special tool and a
hammer.
IMPORTANT: Valve plate (3) and rotor (4) must be
replaced as an assembly.
IMPORTANT: Install valve plate (3) of the rotor (4)
assembly with the slotted hole
facing downward.
2. Apply grease onto the flat surface of valve plate
(3). Align the position of knock pin (14) in pump
casing (2) and install valve plate (3).
IMPORTANT: Check the directions of spring (15)
and retainer (18).
5. Assemble rotor (4) into an assembly in the
following procedures.
• Place rotor (4) with the center projection part
facing upward.
• Assemble springs (15) (4 used) so that the outer
surface is matching with the outer surface and the
inner surface is matching with the inner surface.
Place springs (15) (4 used) to the center
projection part of rotor (4).
15
16
4
3. Install servo pistons (17) (3 used) to pump casing
(2).
IMPORTANT: Check the direction to install
feedback link (26).
4. Align the groove for pin (24) in pump casing (2)
and install the feedback link (26) assembly. At this
time, face link pin (29) to the front casing (8) side.
NOTE: Both surfaces of spring pin (27) are parallel
to each other. Align the parallel surface
with the groove and install the surface.
27
26
2
W176-02-06-015
• Cover spring (15) with bushing (16).
NOTE: When covering bushing (16), aligning the
spline of bushing (16) with the spline of
rotor (4) makes it easy to install the shaft
later.
• Insert plungers (5) (9 used) from the flat surface
of retainer (18) and install them to rotor (4).
6. Evenly tap and install inner race (12) to drive shaft
(11) by using a special tool and a hammer.
7. Install retaining ring (1) to drive shaft (11).
Parallel Surface
Parallel Surface W176-02-04-016
W2-6-15
BODY (UPPERSTRUCTURE) / Pump Device
2
8
10
30
31
11
22
32
43
44
34
35
36 37
45
Detail for Position A
W4GB-02-04-003
W2-6-16
BODY (UPPERSTRUCTURE) / Pump Device
IMPORTANT: Do not damage the oil seal (36)
sliding surface of drive shaft (11).
8. There are two ring grooves in drive shaft (11).
Install retaining ring (32) to the ring groove closer
to the end surface.
9. Check the direction of the inner ring of roller
bearing (34). Tap and install roller bearing (34) to
drive shaft (11) by using a hammer.
34
11
(Inner
Ring)
W4GB-02-04-004
10. Install the roller and the outer/inner ring plates of
roller bearing (34) to drive shaft (11) with the
stamped mark facing out.
11. Install retaining ring (32) to drive shaft (11).
12. Assemble front casing (8) into an assembly in the
following procedures.
• Place front casing (8) with the pump casing (2)
side facing downward.
• Apply grease onto the inner surface of oil seal
(36).
• Evenly tap and install oil seal (36) into front casing
(8) by using a special tool and a plastic hammer.
• Install retaining ring (37) to front casing (8).
• Turn over front casing (8) and place onto a
wooden block of more than 30 mm square (1.2 in
square).
• Install O-ring (31) to front casing (8).
• Install drive shaft (11) to front casing (8). At this
time, by tapping drive shaft (11) by using a plastic
hammer, roller bearing (34) can be inserted
easily.
• Align with pin (35) and install cradle plate