Construction Products, LLC
REPAIR
MANUAL
Manual Part No. 101357
March 17, 2003
MODELS:
795CS
797CS,B
805CS,B
HY-RAM
HAMMER
Repair manual 795CS, 797CS,B and 805CS,B
1
Repair manual 795CS, 797CS,B and 805CS,B
Table of Contents
General....................................................................................................................... 3
1.1
Explanation of the symbols in the repair manual ................................................. 3
2. Operational safety ...................................................................................................... 4
3. Tools, measuring and testing equipment .................................................................... 6
4. Hy-Ram Disassembly ................................................................................................ 7
4.1 Removing the demolition tool ............................................................................... 7
4.2 Removing the Dust Protector ............................................................................... 8
4.3 Removing the percussion mechanism from the 'CS' ............................................ 9
4.4 Removing the high-pressure accumulator.......................................................... 10
4.5 Removing the control valve spool ...................................................................... 11
4.6 Removing the 2 speed components ................................................................... 12
4.7 Removing the energy recovery .......................................................................... 13
4.8 Removing the AutoControl- valve....................................................................... 14
4.9 Removing the cylinder head............................................................................... 15
4.10 Removing the swivel elbows .............................................................................. 17
4.12 Removing the cylinder........................................................................................ 18
4.13 Removing the locking pin assemblies in tool holder ........................................... 19
4.14 Removing the locking pin bushings .................................................................... 19
5. Hy-Ram Repair Procedures..................................................................................... 20
5.1 Tool bushing replacement .................................................................................. 20
5.2 Removing scratches from the control valve spool and bore ............................... 22
5.3 Removing scratches or rough spots on the piston and cylinder bore.................. 22
5.4 Repairing cracked welds in the 'CS' box ............................................................ 23
5.5 Inspect the top damper ...................................................................................... 24
5.6 Inspect the shoulder dampers ............................................................................ 24
5.7 Inspect the guide plates ..................................................................................... 25
5.8 Inspect the dust ring (standard version Hy-Rams only)...................................... 26
6. Changing the seals ................................................................................................... 27
6.1 Changing the cylinder seals ............................................................................... 27
6.3 Changing the seals on the swivel elbow............................................................. 29
6.4 Changing the seals on the seal bushing............................................................. 30
6.5 Changing the bladder in the high pressure accumulator .................................... 31
7. Assembling the hydraulic hammer........................................................................... 32
7.1 Installing the cylinder.......................................................................................... 32
7.2 Installing the piston and seal bushing................................................................. 32
7.3 Installing the cylinder head................................................................................. 33
7.4 Installing the AutoControl ................................................................................... 34
7.5 Installing the energy recovery valve ................................................................... 35
7.6 Installing the 2-speed components..................................................................... 36
7.7 Installing the control valve spool ........................................................................ 37
7.8 Installing the high-pressure accumulator............................................................ 37
7.9 Tightening torque values for Hy-Rams 795CS, 797CS,B and 805CS,B............. 38
7.10 Installing the percussion mechanism in the 'CS' box bracket ............................ 39
7.11 Installing the demolition tool ............................................................................... 40
7.12 Installing the Dust Protector (Guardian® version) ............................................... 41
7.13 Filling the nitrogen pre-charge............................................................................ 42
7.14 Charging the high pressure accumulator............................................................ 43
1.
2
Repair manual 795CS, 797CS,B and 805CS,B
1.
General
In order to maintain the operational safety and reliability of all versions of the 795CS,
797CS,B and 805CS,B hydraulic hammers, repair work should only be carried out by
Allied trained specialists using genuine Allied spare parts. Allied trained specialists know
which parts need replacing and when.
This repair manual applies to the 795CS, 797CS,B and 805CS,B hydraulic hammers.
Ensure that the Parts Manual with the exploded diagram of the individual parts is available
for reference.
1.1
Explanation of the symbols in the repair manual
To emphasise their importance, certain points in the repair manual are marked with
symbols, which are described below.
Please note!
3
These passages contain information on the
correct use of the hydraulic tool and are
aimed at avoiding mistakes during
operation.
Warning!
Passages marked in this way contain
safety information and instructions aimed
at avoiding damage.
Caution!
Passages marked in this way contain
safety information and instructions aimed
at preventing accidents and avoiding
injury.
Repair manual 795CS, 797CS,B and 805CS,B
2.
Operational safety
2.1
General
In order to maintain the operational safety
of the hydraulic hammer, repair work
should only be carried out by trained
specialists using genuine Allied spare
parts. This work should therefore only be
entrusted to Allied trained specialists who
know which spare parts need to be
inspected and or replaced.
2.2
Accident prevention
regulations
Caution!
To avoid the possibility of injury, please
observe the following instructions
Please familiarise yourself with the repair
manual and the appropriate regulations
before starting work on the hydraulic
hammer.
When operating or working on hydraulic
hammers the regulations and valid local
statutes for accident prevention and
regulations covering pressurised vessels
will apply.
The hydraulic hammer should only be
repaired by trained specialists.
When lifting/transporting the hydraulic
hammer, use only the lug provided and
hoisting equipment with sufficient capacity.
Clear hand signals must be agreed on with
the hoist operator beforehand.
Never stand beneath hoisted loads.
Stand the hydraulic hammer in a suitable
location and secure it against falling over.
The repair area must be clear and easily
accessible.
Always wear protective glasses when
installing or removing the demolition tool
due to metal splinters that may fly off when
hammering out the lock pins.
Demolition tools should only be serviced as
described in the operating manual.
Caution!
The Hy-Ram hydraulic hammers nitrogen
pre-charge chamber is pressurised.
Before dismantling the hydraulic hammer
and before removing the complete fill valve
“G”, the pre-charge chamber must be fully
depressurised.
Never use nails, screwdrivers or similar
objects to bleed off the gas since this may
damage the fill valve. Bleed off the gas
using only the test hose provided in the
nitrogen pre-charge kit.
Never use your fingers to check the
alignment of the demolition tool retainer bar
recesses to the retainer bar bores in the
tool holder.
Never dismantle a Hy-Ram hydraulic
hammer that is still hot from running, as
there is a high risk of injury from burns.
Always wait until the hammer has cooled
down before dismantling it. Collect any oil
that runs out and dispose of it properly.
Caution
Risk of explosion!
The nitrogen pre-charge chamber must
only be filled with dry nitrogen gas. Make
sure that no other gas (e.g. air or oxygen)
is allowed into the nitrogen pre-charge
chamber.
4
Repair manual 795CS, 797CS,B and 805CS,B
2.3
Operating consumables
Use
5
Highperformance
grease with
Molly base
Demolition
tool
lubrication
Nitrogen N2
Filling the
- highpressure
accumulator
- pre-charge
chamber
Abrasive
polishing
paper, grain
600
Removing
scratches
Anti-seize
Wear
bushings
Comments
Allied chisel paste
(see operating
manual)
Caution!
Used on OD during
bushing installation
Repair manual 795CS, 797CS,B and 805CS,B
3.
Tools, measuring and testing equipment
3.1
Tools
The tools required for dismantling and re-assembling the 795CS – 805B are listed below:
Description
Qty.
795 / 797CS,B
805CS,B
X
X
X
X
X
X
X
P/N 657488
1
1
1
2
2
2
X
X
X
P/N 676762
1
X
X
Qty.
795 / 797CS,B
805CS,B
1
1
1
1
1
1
1
1
1
1
1
1
X
X
X
X
X
X
X
X
X
Nitrogen Pre-Charge Kit
Accumulator Charge Kit
P/N 657341
Lifting Eye - Piston*
Lifting Eye - Head
P/N 678306
Lifting Eye - Head*
Lifting Eye - Cylinder
Dust Wiper Remover
(Guardian Version Only)
P/N 678306
P/N 657604
P/N 678136
Items Not Supplied By Allied
Description
Sledge hammer
5 lb.
Sledge hammer
10 lb.
Grease gun
Torque Device
10,000 ft/lbs.
Torque Device Socket
65mm
Torque Device Socket
75mm
0- 370 ft./lbs.
Torque Wrench**
Crows Foot Wrench
55 mm
Inside Micrometer
6" - 7"
Inside Micrometer
7" - 8"
Rubber Mallet
OD Snap Ring Pliers
Large
Allen Wrenches
5mm- 22mm
Screw drivers
SM, MD, LG
Combination Wrenches 13 - 60 mm
Sockets & Wrench
8 - 30 mm
Nitrogen (N2) Gas
Cylinder
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
* Lift Eye P/N 678306 will fit the pistons found in the 795CS, 797CS,B and 805CS,B HyRams and is also used in two locations in the Cylinder Head of the 805CS,B.
** Additional reducing adapters may be required to connect the Torque Wrench to the
large sockets used for Tension Bolt installation.
6
Repair manual 795CS, 797CS,B and 805CS,B
4.
Hy-Ram Disassembly
4.1
Removing & measuring the
demolition tool
x Lay the hydraulic hammer horizontally.
x Using a suitable drift and a hand-held
hammer, remove the upper retainer bar
locking pin (1) by driving it out as
illustrated in Fig. 1. Also see section 4.14.
Caution!
Wear protective glasses and gloves!
Risk of injury from flying metal splinters!
x Remove the two retainer bar seals (2)
from their bores. A screwdriver can be
used to assist in prying them out.
x Remove the retainer bars (3).
The retainer bars have an M12 threaded
bore on the front end.
Use an M 12x150 bolt, inserted into the
threaded bore as a handle to pull out the
retainer bar.
x Remove the demolition tool (4) from the
bore in the tool holder with a sling and
lifting device.
x If burring is detected when removing the
working tool or the two retainer bars it
must be ground off carefully. If excessive
wear such as sharp edges, notches or
heavy indentations are detected, the
retainer bars must be replaced. In addition
all four sealing plugs must be checked or
replacements provided if any are missing.
x If the working tool shank is worn, the
diameter must not fall below a minimum of
"D" (Fig. 2).
7
Fig. 1
Removing the demolition tool
Fig. 2
Checking minimum diameter on working
tool
Model
Minimum diameter D
795CS
6.102" (155 mm)
797CS,B
6.299" (160 mm)
805CS,B
8.070" (175 mm)
Repair manual 795CS, 797CS,B and 805CS,B
4.2
Removing the Dust Protector
(Guardian® version)
x Knock out the locking pins (1) for the Dust
Protector using a punch and a hand-held
hammer (Fig. 2).
Caution!
Wear protective glasses!
Risk of injury from flying metal splinters!
x The guide ring (5) may be tight in the bore
due to dust accumulation. A few blows
from the hand-held hammer will loosen
the guide ring (5) (Fig. 1).
x Remove the guide ring (5), floating ring (4)
and support ring (2) (Fig. 1).
Fig. 1
Removing the Dust Protector
x Remove tool wiper (2) using the removal
tool (3), P/N 676762. Adjust to fit and
operate tool in direction of arrow. (Fig. 2).
Fig. 2
Removing the tool wiper
8
Repair manual 795CS, 797CS,B and 805CS,B
4.3
Removing the percussion
mechanism from the 'CS'
box bracket
Caution!
x Position the Hy-Ram hydraulic hammer
horizontally on cribbing to allow access to
all mounting bracket fasteners.
x Mark the position of the mounting bracket.
Attach a lifting device to the bracket and
remove the fasteners and bracket.
x Remove the top damper (Fig. 1).
Fig. 1
Removing the top damper
Warning!
x Stand the 'CS' box and hammer assembly
vertical and secure the box to prevent it
from falling over.
x On those units equipped with AutoLube II
or any automatic lubricator, remove all
grease/oil lines between the lubricator and
the hydraulic hammer.
x Insert the appropriate lifting eyebolts into
the two threaded bores on the upper face
of the cylinder head as far as they will go.
Reference section 3.1 in this manual for
proper lift eye selection.
x Attach a suitable lifting device to the lift
eyes and remove the percussion
mechanism of the 'CS' box (Fig. 2).
Caution!
x Excessive deposits of dirt and debris
between the percussion mechanism and
the 'CS' box may require that the box be
secured and the hammer pulled out.
9
Fig. 2
Lifting the percussion mechanism out of
the 'CS' box
Repair manual 795CS, 797CS,B and 805CS,B
4.4
Removing the high-pressure
accumulator
x Stand the Hy-Ram hydraulic hammer
vertically and secure against falling over.
N
Caution!
If the Hy-Ram is still attached to the carrier, it
is imperative that the hydraulic system must
be depressurised prior to removing the highpressure accumulator.
x Release any pressure accumulated in the
carriers hydraulic reservoir.
x Close the ball valves at the end of the
dipper stick on the carrier.
x Loosen the JIC fittings on the whip hoses
to relieve any trapped pressure.
x Loosen and remove the four accumulator
tension bolts and washers (1), while
supporting the weight of the accumulator
(Fig. 3).
x Collect any oil that runs out and dispose of
it properly.
x Remove high-pressure accumulator (Fig.
4) and store on a protective surface.
x Inspect the thread inserts in the
accumulator tension bolt bores and
replace if necessary.
x Inspect the accumulator tension bolts and
replace if necessary.
Fig. 3
Removing the accumulator mounting bolts
N
Fig. 4
Removing the high-pressure accumulator
Warning!
The high-pressure accumulator on models
795CS, 797CS,B and 805CS,B has a
capacity of 1.5 litre and a maximum allowable
operating pressure of 2900psi (200 bar).
Those accumulators identified with an “N” on
the front shell (Figs. 3 & 4), are rated at a
maximum pressure of 3300psi (227 bar).
10
Repair manual 795CS, 797CS,B and 805CS,B
4.5
Removing the control
valve spool
x Unscrew the M20 Allen bolts (1) from the
valve cover (2) using a size 17mm Allen
wrench (3) (Fig. 5).
Fig. 5
Removing the Allen bolts
x Insert two of the M20 Allen bolts into the
threaded bores in the valve cover and use
them as pusher bolts to remove the
control valve cover (Fig. 6).
Fig. 6
Removing the control valve cover
x Remove the control slide valve (1) from its
bore, observing the direction of removal.
(Fig. 7)
Fig. 7
Removing the control slide valve
11
Repair manual 795CS, 797CS,B and 805CS,B
4.6
Removing the 2-speed
components
(795CS ser. no. 1148 & below only)
(805CS ser. no. 0999 & below only)
x Remove the thread adapter (1) (Fig. 8)
x Remove the frequency valve spring (2)
and the frequency valve piston (1)(Fig. 9).
Please note!
Use a M5 x 60 screw to remove the valve
piston (1) (Fig. 9). Observe the position of
parts upon removal!
x On older models using a frequency valve
piston without the depicted drain bore
(Fig. 9), a spacer sleeve may be installed
between the valve spring and the valve to
lock the system in low speed / high impact
(Fig. 10). Those units that are equipped
with a drain bore can simply be capped at
the 2-speed port for continuous low speed
/ high impact operation.
x To lock the 2-speed frequency switching
system in high speed / low impact (all 2speed models), the spacer sleeve is
positioned between the thread adapter
and the frequency valve piston (Fig. 11).
Fig. 8
Removing the 2-speed components
Fig. 9
2-speed system components
Fig. 10
Locking in low speed / high impact on older
models not equipped with a drain bore.
x Remove the spacer sleeve when
operating on carriers equipped with an
Allied 2-speed switching kit.
Fig. 11
Locking in high speed / low impact
12
Repair manual 795CS, 797CS,B and 805CS,B
4.7
Removing the energy recovery
valve
(795CS ser. no. 1148 & below only)
(805CS ser. no. 0999 & below only)
x Remove the energy recovery spacer plug
(1) using a 12mm Allen wrench (2)
(Fig.12).
x Remove the valve piston (1) from the
valve sleeve using a hook (2) or by
carefully inserting the tapered end of a
wooden pencil into the valve piston bore.
x Note the direction in which it is removed
(Fig. 16).
x Pull the valve sleeve (1) out of the bore
using a hook (2) or if necessary an inside
diameter pulling device.
13
Fig. 12
Removing the energy recovery spacer plug
Fig. 13
Removing the valve piston
Fig. 14
Direction in which valve piston is removed
Fig. 15
Removing the valve casing
Repair manual 795CS, 797CS,B and 805CS,B
4.8
Removing the AutoControlvalve
(795CS S/N 1149 & up and 797,B only)
(805CS S/N 1000 & up and 805B only)
x Remove the Auto Control plug (1) using a
size 22 Allen wrench (2). Remove the Oring (3) from the Auto Control plug (Fig.
16).
Please note!
The Auto Control plug (1) is affixed with
Loctite.
Fig. 16
Removing the Auto Control plug and ORing
x Insert a M3x50 bolt (2) into the threaded
bore on the upper face of the AutoControl
valve (1) and pull the complete valve out
of the bore (Fig. 17).
Please note!
If the AutoControl valve is defective or nonfunctional, it is not repairable. Use a complete
new AutoControl valve to reassemble the
hammer.
Fig. 17
Removing the AutoControl valve
14
Repair manual 795CS, 797CS,B and 805CS,B
4.9
Removing the cylinder head
Caution!
Before removing the cylinder head, the
nitrogen gas must be evacuated from the
nitrogen pre-charge chamber.
(Do not unscrew the fill valve from cylinder
head until the pre-charge chamber has been
evacuated).
Fig. 18
Removing the fill plug from port “G”
x Unscrew the plug from the fill valve port
“G” using a 5 mm Allen wrench (Fig. 18).
x Push the nozzle of the fill hose (1) into fill
valve and support the free end of the hose
to prevent a whipping action. The nitrogen
gas will evacuate through the free end of
the hose (Fig. 19). If hydraulic oil
evacuates through the fill hose, the upper
seals in the seal bushing must be
serviced.
x Reinstall the fill valve plug to prevent loss.
15
Fig. 19
Releasing the nitrogen pre-charge
Repair manual 795CS, 797CS,B and 805CS,B
Please note!
Release the tension rod nuts or tension bolts
by rotating them counter clockwise with an
electric, pneumatic or hydraulic powered
wrench (Fig. 20). Tension rods are those
fasteners equipped with a removable nut at
both ends. Tension bolts have a fixed head at
the top and a removable nut or thread insert
at the bottom. Always refer to the appropriate
torque for the specific style of fastener.
Caution!
Risk of injury when supporting and operating
a powered wrench.
Please note!
Mark all nuts, washers and tension bolts or
rods, so that matching sets remain together.
Fig. 20
Releasing tension bolts with an electric
powered wrench
x Remove the tension bolts. On models
equipped with tension rods, it will be
necessary to remove the cylinder head
before the rods can be removed via a
double nutting procedure.
x Insert the appropriate two lifting eyebolts
into the threaded bores on the top of the
cylinder head as far as they will go. Lift the
cylinder head off using a hoist/crane (Fig.
21) and store on a protective surface.
Warning!
Fig. 21
Removing the cylinder head
Collect any oil that runs out and dispose of it
properly.
16
Repair manual 795CS, 797CS,B and 805CS,B
4.10 Removing the swivel elbows
x Remove the retaining ring (1) from the
flange (2) using snap ring pliers.
x Remove the spacer (3).
x Pull the body (4) off of the flange.
x Remove the socket head bolts (5) using a
10 mm Allen wrench.
x Remove the flange (2) from cylinder head.
Warning!
Collect any oil that runs out and dispose of it
properly.
Fig. 22
Removing the swivel elbows
17
Repair manual 795CS, 797CS,B and 805CS,B
4.11 Removing the piston and seal
bushing
x After removal of the cylinder head, insert
the lifting eyebolt P/N 678306 (1) fully into
the threaded bore in the piston (Fig. 1).
x Remove the piston (3) and seal bushing
(2) out of the cylinder bore as an
assembly, using a hoist/crane and store
horizontally on wooden 'V' blocks on a
protective surface (Fig. 1).
x Remove the hoist/crane from the lifting
eyebolt and use a rubber mallet to remove
the seal bushing (2) from the piston.
Please note!
Remove the piston in vertical position only.
Fig. 1
Removing the percussion piston
Warning!
Collect any oil that runs out and dispose of it
properly.
4.12 Removing the cylinder
x Insert lifting eyebolts P/N 657488 fully into
the threaded bores in the sides or front of
the cylinder.
x Lift the cylinder off of the tool holder using
a hoist/crane and store on a protective
surface. (Fig. 2).
Warning!
Fig. 2
Removing the cylinder
Collect any oil that runs out and dispose of it
properly.
18
Repair manual 795CS, 797CS,B and 805CS,B
4.13 Removing the locking pin
assemblies for the retainer
bars and wear bushings in the
tool holder
x Knock out the locking pin using the pin
punch and a hand-held hammer (see Fig.
1).
Caution!
Wear protective glasses and gloves!
Risk of injury from flying metal splinters!
Fig. 1
Knocking out the locking pin
4.14 Removing the locking pin
bushings
x Insert a screwdriver behind the plastic
bushing (Fig. 2).
x Use the screwdriver to lever the locking
pin bushing out of the bore. The locking
pin bushing must be replaced if the
locking pin can be pushed out of the bore
by applying firm finger pressure.
19
Fig. 2
Removing the locking pin bushing
Repair manual 795CS, 797CS,B and 805CS,B
5.
Hy-Ram Repair Procedures
5.1
Tool bushing replacement
Please note!
The tool bushings must be changed when
their inside diameter has reached the value in
the table below. Measurements should be
taken from front to back, (the retainer bar
bores are on the front and back of the tool
holder) as this represents the direction of
work. See chapter 4.1 for tool dimensions.
Model
Max. permissible inside
diameter
795CS
6.496” (165 mm)
797CS,B
6.690” (170 mm)
805CS,B
7.283” (185 mm)
x Apply several thick radial beads of weld to
the inside of the worn tool bushing using
an electrode welder Fig. 1. The beads
should form complete circles within the
bushings inner diameter.
x The same procedure can be applied for
the impact ring. In addition to the inner
welding, a push plate may be welded into
the ring, as shown in Fig. 2.
x Upon cooling, the tool bushings and
impact ring contract and loosen in their
bore.
x Knock out the bushing locking pins using a
punch and hand hammer. See sections
4.14 & 4.15.
Fig. 1
Bushing with radial welding beads
Push Plate
Fig. 2
Push plate welded into impact ring
Caution!
Wear protective glasses!
x Remove the bushings and impact ring by
pressing or driving out with a hammer
(Fig. 3).
Fig. 3
Direction of removal for tool bushings
20
Repair manual 795CS, 797CS,B and 805CS,B
x Thoroughly clean and inspect the bore of
the tool holder. The impact ring seat must
be flat and level to properly support the
new impact ring (Fig. 4). If the new impact
ring is not sufficiently supported during
operation,
it
can
break
causing
catastrophic damage to the piston and tool
holder. Remove any burrs or rough spots
in the bore.
x Before installing the new impact ring,
submerge it in liquid nitrogen (N2) to super
cool it and reduce its diameter.
Caution!
Use tongs or pliers to handle cooled parts,
never use your hands! Wear heavy gloves,
long sleeves and eye protection when
working with liquid nitrogen (N2).
x Install the impact ring with the bevelled
edge away from the seat (Fig. 4).
x Coat the OD of the upper and lower tool
bushings with anti-seize compound and
install (these do not require cooling as the
new design features a 'slip fit').
Please note!
The tool bushings recesses must be aligned
with the bores for the locking pins in the lower
hammer part!
x Install the locking pins.
Caution!
Wear protective glasses and gloves!
21
Fig. 4
Installing the impact ring against a flat level
seat.
Repair manual 795CS, 797CS,B and 805CS,B
5.2
Removing scratches from the
control valve spool and bore
Please note!
The control valve spool must be able to move
easily in the bore. If this is not the case,
inspect both surfaces to determine the cause
of binding.
x Remove control valve spool (see Chapter
4.5).
x Smooth any scratches on the control valve
spool using emery cloth.
x Check the bore for scratches, if necessary
smooth by using emery cloth.
x Carefully clean treated surfaces then oil
lightly with hydraulic oil.
x Install the control valve spool (see
Chapter 7.7).
If scratches on the spool cannot be fully
removed by careful polishing, replace the
control valve spool.
5.3
Warning!
Raised ends associated with scratches on
the piston or the cylinder must be carefully
deburred.
x Thoroughly clean the repaired parts and
all grooves and lubricate with hydraulic
oil.
x Install the piston (see Chapter 7.2).
x Install the cylinder head (see Chapter
7.3).
If scores or galling cannot be fully
removed by careful polishing, new parts
may be required.
Removing scratches or rough
spots on the piston and
cylinder bore
Please note!
x Remove the cylinder head (see Chapter
4.9).
x Remove the piston (see Chapter 4.11).
If scores can be seen on the removed
piston they must be smoothed by
mechanical finishing or manual polishing
with emery cloth. The piston diameter may
not be reduced by more than .002" (0.05
mm) by mechanical reworking.
x Check the cylinder bore for scratches,
polish smooth if necessary using emery
cloth.
22
Repair manual 795CS, 797CS,B and 805CS,B
5.4
Repairing cracked welds in the
'CS' box
If cracked welds are detected, they can be
repair-welded after the hammer and the
plastic elements have been removed from the
hammer box.
After the necessary preparations have been
made, repairs can be carried out.
The necessary preparations include:
x Cleaning the points in question.
Point 1:
Side
plate/top
plate joint
Point 2:
Side plate /
damping
element
bearing joint
x Grinding down the cracks until the weld is
crack-free.
x Providing suitable weld fillers (electrodes
or wire such as used for steel grade St.523, e.g. MAG wire SG2/SG3 or E7018
electrodes).
x Preheat the zone to be repair-welded to
approx. 212°F (100°C).
x Welds must be made without notches or
ground free of notches in order to reduce
tension.
If possible, the repair zone should be filled
and welded from both sides.
23
Point 3:
Side plate /
bottom
plate joint
Repair manual 795CS, 797CS,B and 805CS,B
5.5
Inspect the top damper
Once the mounting bracket has been
removed, the top damper can be taken out
and inspected.
The table below gives the minimum allowable
height for the top damper. Refer to Fig. 1.
Model
Dimension h
795CS / 797CS,B
3.385" (86 mm)
805CS,B
4.173" (106 mm)
Excessive carrier down pressure on the
hammer during use can cause the material of
the top damper to "flow" over the edges of the
upper hammer part, causing the material to
crack from fatigue and leaving notches.
As time goes on these notches get bigger and
can cause larger pieces of the top damper
pad to break off.
5.6
Inspect the shoulder dampers
Fig. 1
Check dimension ”h” and inspect for
fatigue cracks or notches in the top damper
Fig. 2
The height dimension ”h” of the shoulder
dampers (Fig. 2) should also be measured
upon
disassembly
to
determine
if
replacement is necessary. Replace the
shoulder dampers in pairs. The table below
shows the minimum dimension for area ”h”.
Model
Dimension h
795CS / 797CS,B
1.220" (31 mm)
805CS,B
1.555" (39.5 mm)
Check dimension ”h” and inspect for
fatigue cracks or notches in the shoulder
damper
24
Repair manual 795CS, 797CS,B and 805CS,B
5.7
Inspect the guide plates
Abrasion
The guide plates are subject to wear during
normal use. The penetration of dust and dirt
along with surface pressure cause heavy
abrasion to the plates.
Conchoidal
fracture
Depending on condition, the guide plates may
be replaced individually or in sets.
Cracks
By measuring the thickness of the plates it is
possible to determine whether replacement
can be postponed by inserting thin metal
sheets as shims (Fig. 4).
Dirt deposits
When shimming, use sheet metal cut to the
profile of the pad being shimmed. The
minimum allowable dimension for an
individual guide plate is .787" (20 mm).
Abrasion
Fig. 3
Possible wear and damage to the guide
plates
Warning!
Service openings must remain accessible!
The table shows the reference thickness of
the guide plates.
Model
Dimension h
795CS / 797CS,B
.866" (22 mm)
805CS,B
.866" (22 mm)
Plate thickness is mostly only wear-reduced
locally. A decision on whether to replace the
guide plates therefore depends on the
general condition of the parts in each case.
Metal
Shim
Guide
plate
Hammer
Fig. 4
Check dimension ”h” and arrangement of
shims in the desired thickness
25
Repair manual 795CS, 797CS,B and 805CS,B
The upper guides are made from special
foamed plastic (PUR) and therefore have a
certain degree of elasticity (Fig. 8).
After removing the hammer, these plates can
be removed from their guides and examined.
Here again, a decision is made depending on
the individual condition of the plates as to
whether replacement is necessary.
5.8
Inspect the dust ring (standard
version Hy-Rams only)
The dust ring and its seat on the lower face of
the hammer box must be checked regularly
and cleaned if necessary to prevent rock dust
from becoming baked on.
If baked-on rock dust in the seat impedes the
sealing function of the dust ring, it must be
replaced by a new one (Fig. 9).
Upper guides
Fig. 8
Location of guides
x After removing the demolition tool, the
dust ring is freely accessible and can be
levered out of its seat using a screwdriver.
x The baked-on rock dust is cleaned off the
seat using a suitable tool.
x After examination, reinstall either the old
dust ring or insert a new one in the seat in
the 'CS' box.
Warning!
Fig. 9
Checking the dust collar
Never use a steam cleaner to clean the dust
ring seat as water spray may contact the
piston causing rust.
26
Repair manual 795CS, 797CS,B and 805CS,B
6.
Changing the seals
6.1
Changing the cylinder seals
x Remove the cylinder head (see Chapter
4.9).
x Remove the percussion
Chapter 4.11).
piston
(see
x Remove the cylinder (see Chapter 4.12).
x Check the cylinder bore for scratches. In
the majority of cases scratches can be
smoothed off using grain 600 emery cloth.
805B & 805CS: From S/N 0850 & up
797,B & 795CS: From S/N 0912 & up
805CS: Below Serial-No. 0850
x Once the cylinder bore has been washed
clean and lightly coated with hydraulic oil,
the new sealing elements can be installed.
Use the table below to determine the proper
sealing part numbers based on serial number.
795CS from S/N 0912 & up, all 797CS,B
805CS from S/N 0850 & up, and all 805B
Description
795/797CS,B 805CS,B
Wiper
676961
676962
O-Ring
677938
678315
Step seal
677937
678314
Cup seal w/ ring
676971
676970
795CS below S/N 0912
805CS below S/N 0850
Description
795CS
Wiper
676961
O-Ring
677938
Step seal
677937
Cup seal w/ ring
676971
805CS
676962
678315
678314
676970
795CS: Below Serial-No. 0912
Fig. 1
Detail X
Use only new and genuine Allied spare parts.
Warning!
Changing the cylinder seals
When installing the back-up ring, observe the
position of the one rounded corner (see Fig.
1, Detail X).
27
Repair manual 795CS, 797CS,B and 805CS,B
The following diagrams indicate how the
sealing elements should be pressed out of
shape for installation.
x Insert the cup seal (with the back-up ring
removed), in the groove closest to the
center of the cylinder. The cup seal should
be carefully deformed as shown in Fig. 2
for installation.
x Install the back-up ring (1) with the one
rounded corner entering the cup seal.
x Install the O-ring (lubricated with hydraulic
oil) into the middle groove. Refer to Fig. 1
for a serial number break.
Cup seal with back-up ring
x Install the step seal (lubricated with
hydraulic oil) directly over the O-ring with
the step facing the center of the cylinder.
Refer to Fig. 1 for a serial number break.
The step seal should be carefully
deformed as shown in Fig. 2 for
installation.
Step Seal
Warning!
Excessive kinking will cause cracks and
subsequent failure.
x Install the wiper in the groove furthest
from the center of the cylinder. The lip of
the seal should be facing the tool holder.
Refer to Fig. 1. After snapping into the
groove, check the fit of the seal visually
and also by using your fingers.
x Roll a clean round wooden or plastic rod
around the circumference to press the
seals back into shape and ensure a
correct fit.
x Install the cylinder (see chapter 7.1).
x Install the piston (see chapter 7.2).
x Install the cylinder head (see chapter 7.3)
Fig. 2
Pressing the seals out of shape for
installation
28
Repair manual 795CS, 797CS,B and 805CS,B
6.2
Changing the seals between
the cylinder and cylinder head
x Remove cylinder head (see Chapter 4.9).
x Replace the following seals:
Description
Flat seal
Flat seal
O-ring**
Back-up ring***
3
795/797CS,B 805CS,B
678671
678667
679509
??????
678672*
678667
678316
??????
Fig. 3
Cylinder seal placement
* 805CS's below S/N 0631 use P/N 678671
** O-ring to be installed in the cylinder head
*** Used on 797B S/N 1780 & up and 805B
S/N 1420 & up only, below the O-ring.
x Lubricate all flat seals (1&2) with
assembly grease and install into the
grooves in the cylinder. Fig. 3
x The O-ring depicted in Fig. 3 must be
installed into the provided groove in the
cylinder head. Refer to chapter 7.3 for
proper O-ring installation. Install the
cylinder head (see Chapter 7.3).
6.3
Changing the seals on the
swivel elbow
x Disassemble the swivel elbows (Chapter
4.10).
x Refer to Fig. 4. Replace following seals:
O-ring
O-ring
Back-up ring
(1)
(2)
(3)
658848
678686
678685
Early models of the 795CS & 805CS may
have a different swivel configuration. Refer to
your parts manual for further clarification.
x Install the swivel elbows in reverse order
of chapter 4.10.
29
Fig. 4
Replacing the seals on the swivel elbow
Repair manual 795CS, 797CS,B and 805CS,B
6.4
Changing the seals on the
seal bushing
Please note!
The quadring seal (4) and/or the O-ring (1)
must be replaced if gas bubbles are observed
in the oil of swivel elbows after raising the
pressure in the nitrogen pre-charge chamber
to 350 psi. with the hammer lying horizontal.
Observe the return port first, then cap the
return and top off the pressure port with clean
hydraulic fluid to observe it.
Install this way
795CS, 797CS & 805CS
The step seals (2) must be replaced if
hydraulic oil is detected in the nitrogen precharge chamber.
When changing the step seals, ensure that
the step is facing the oil side (away from the
quadring) on both seals.
x Remove the cylinder head (chapter 4.9).
x Remove the piston and seal bushing
(chapter 4.11).
x Remove the seal bushing from the piston
(chapter 4.11).
x Remove all seals from the seal bushing
paying attention to the direction in which
they were installed.
x Thoroughly clean the seal bushing in
solvent and dry with compressed air.
x Lubricate the new seals in hydraulic oil
and install. Refer to Fig. 5 for directions
on seal placement. The back-up rings (5)
have one contoured side that must face
the O-ring (1).
x Install the seal bushing (see chapter 7.2).
x Install the cylinder head (see chapter 7.3).
1
3
2
4
797B & 805B
Fig. 5
Changing the seals on the seal bushing
Replace the following seals:
Description
1) O-ring
2) Step seal
3) O-ring
4) Quadring
5) Back-up ring
Description
1) Nitrogen Cup seal
2) Cup seal w/ ring
3) Double lip seal
4) Pressure ring
795/797CS
677839
677941
677942
677943
679535
805CS
659548
678313
678315
678318
680535
797B
102286
101389
101287
102089
805B
101392
101391
100288
102090
30
Repair manual 795CS, 797CS,B and 805CS,B
6.5
Changing the bladder in the
high pressure accumulator
x Remove the high pressure accumulator as
described in chapter 4.4.
x Bleed off any remaining gas by slowly
removing the Phillips head screw (1) in the
center of the accumulator. Fig. 6.
x Remove the sixteen threaded fasteners
(2) that hold upper and lower shell halves
together.
x Remove the bladder (4) and back up ring
(3) paying attention to the direction that
they were installed.
x Clean all metal parts thoroughly and
visually inspect for defects.
Warning!
Examine both halves of the accumulator body
for cracks and discard if cracks are evident or
previous cracks were welded. Use a straight
edge to check the mating surfaces of the
upper and lower halves. Replace the
accumulator if warping is detected.
x Lightly coat the outer edge of the new
bladder (4) with hydraulic oil and set it into
the lower accumulator half with the metal
button facing the oil feed port.
x Apply a light coat of hydraulic oil to the
back up ring (3) (included with the
bladder) and with the wedge side down,
set it on top of the bladder. (See Detail A)
x Place the upper shell on top of the lower
shell.
x Apply Slip-kote molly paste to the sixteen
threaded fasteners (2) and torque evenly
in a criss-cross pattern to 175 ft/lbs.
x Lubricate and install a new O-ring on the
Phillips head screw (1) and insert the
screw.
x Refer to chapter 7.14 for nitrogen filling
instructions.
31
Detail A
1
2
3
4
Fig. 6
Changing the bladder in the high pressure
accumulator
Repair manual 795CS, 797CS,B and 805CS,B
7.
Assembling the hydraulic
hammer
7.1
Installing the cylinder
x Stand the tool holder upright and secure it
against falling over, and clean the contact
surface. Lubricate tension bolt thread
inserts with Slip-kote molly paste; where
used, making sure insert bores are free of
trapped oil.
x Lubricate the grease port seal (5) and
install. Reference Fig. 1.
x Insert the alignment pin (7).
x Install the lifting eyebolts (3) fully into the
cylinder (4) and position it on the tool
holder (8) with a hoist/crane and remove
the eyebolts.
Fig. 1
Installing the cylinder
x Install O-ring (1) as described in chapter
7.3.
7.2
Installing the piston and seal
bushing
x Clean the piston (2) and coat with hydraulic oil. Reference Fig. 2.
x Install the lifting eyebolt 678306 (3) fully
into the piston (2) and insert it into cylinder
as far as it will go (Fig. 2). Do not tilt the
piston.
x Remove the piston lifting eyebolt.
x Lubricate the seals in the seal bushing (1),
and install the seal bushing onto the
piston (2) with the quadring or nitrogen
cup seal end up.
Please note!
A rubber mallet may be required to fully install
the seal bushing.
Fig. 2
Installing the seal bushing
32
Repair manual 795CS, 797CS,B and 805CS,B
7.3
Installing the cylinder head
x Install the lifting eyebolts fully into cylinder
head.
x Lubricate the O-ring (1) (Fig. 3) lightly with
assembly grease and install it. At first
attempt it will appear that the O-ring is too
large. Although tight, the O-ring can be
installed. The fit of this O-ring is what will
hold it in the groove as the cylinder head
is installed. On later models 797B & 805B,
the O-ring receives a back-up ring just
below it (toward outside) cup against the
O-ring and both in the same groove.
x Insert the alignment pin into the upper
surface of the cylinder.
x If assembling with tension rods (described
in chapter 4.9) the threads must be
lubricated with Slip-kote molly paste and
inserted into the lower nuts hand tight
before the head is installed.
x Install the cylinder head using a
hoist/crane. The cylinder head will hang
level from the hoist with the high-pressure
accumulator removed. Before final
positioning, ensure the O-ring (1) (Fig. 3)
is still in its correct position.
x Remove the lifting eyebolts (4) from the
cylinder head.
x Lubricate the tension bolt threads,
receiving threads (3), and both sides of
the washer with Slip-kote molly paste and
insert the tension bolts (1) (Fig. 5) with
one washer each (2) into the bore.
Tension rods (as described in chapter 4.9)
must be inserted hand tight before the
cylinder head is installed.
Warning!
The washers (2) are conical on one side.
When installing, the conical side must be
facing the head of the tension bolts.
x Refer to the torque table in chapter 7.9 for
the tension bolt tightening information.
33
Fig. 3
Installing the O-ring in the head
Fig. 4
Installing the cylinder head
Fig. 5
Installing the tension bolts
Repair manual 795CS, 797CS,B and 805CS,B
7.4
Installing the AutoControl
valve
(795CS ser. no. 1149 & above only)
(805CS ser. no. 1000 & above only)
All 797B & 805B
1
x Insert AutoControl valve (1) (Fig. 6) in the
corresponding bore in the cylinder head.
x The AutoControl valve (1) must be able to
slide freely in the bore of the cylinder
head.
2
x Unscrew the M3x50 bolt (2) from the
AutoControl valve.
Please note!
Fig. 6
Installing the AutoControl valve
If the AutoControl valve is defective or nonfunctional, it is not repairable. Use a new
AutoControl valve to reassemble the hammer.
x Provide the AutoControl plug (2) (Fig. 7)
with a new, lubricated O-ring (1). Apply
Loctite “super fast” adhesive (270) to the
threads of the plug and install it into the
AutoControl bore.
1
2
x Tighten the AutoControl plug (2) using a
22 mm, Allen wrench (3) Refer to chapter
7.9 for torque values.
3
Fig. 7
Installing the AutoControl plug
34
Repair manual 795CS, 797CS,B and 805CS,B
7.5
Installing the energy recovery
valve
(795CS ser. no. 1148 & below only)
(805CS ser. no. 0999 & below only)
x Insert the valve piston (2) (Fig. 8) in the
valve casing (1) and insert them together
into the corresponding bore in the cylinder
head.
Please note!
Installation
direction
Install the valve piston so that the large hole
faces the outside of the hammer (Fig. 8).
The valve piston (2) must be able to move
freely in the valve casing (1).
Fig. 8
Installing the energy recovery valve piston
x Install a new, lubricated O-ring on the
energy recovery spacer plug (1) and insert
it into the bore. Tighten using a 12 mm
Allen wrench (2) to the torque value listed
in chapter 7.9 (Fig. 9).
Fig. 9
Installing the energy recovery spacer plug
35
Repair manual 795CS, 797CS,B and 805CS,B
7.6
Installing the 2-speed
components
(795CS ser. no. 1148 & below only)
(805CS ser. no. 0999 & below only)
x Install the frequency valve spring (1) (Fig.
10) and the frequency valve piston (2) in
the corresponding bore in the cylinder
head.
x Install the thread adapter (3) and tighten
to the value given in chapter 7.9.
Please note!
Fig. 10
2-speed frequency switching system
When attaching the Hy-Ram to carriers not
equipped with a hydraulic 2-speed switching
kit, a spacer sleeve may be installed to
mechanically lock the hammer in a given
operational mode.
x Blocking the frequency switching
system in low speed / high impact is not
necessary as the valve spring (1) holds
the valve piston (2) in end position (Fig.
10).
x Overflow oil gathering on the side of the
valve piston opposite the spring runs back
to the tank via a bore. In older hammer
models (valve piston without a drain bore)
the spacer sleeve is fitted on the spring
side (see chapter 4.6) or updated by
ordering a new piston.
Fig. 11
Locking in high speed / low impact
x Blocking the frequency switching
system in high speed / low impact is
possible by installing the spacer sleeve (1)
between the frequency valve piston and
the thread adapter (Fig. 11).
36
Repair manual 795CS, 797CS,B and 805CS,B
7.7
Installing the control valve
spool
x Check condition and function of Heli-Coil
thread inserts in the cylinder head, replace
if necessary.
x Lubricate the control valve spool (1) (Fig.
12) with hydraulic oil and install in the bore
of the cylinder head.
x The control valve spool will only properly
fit and fall to the bottom of the bore in one
direction.
Warning!
When installing the control valve cover,
always use a new, lubricated O-ring.
Fig. 12
Fitting the control slide valve
x Install the valve cover, ensuring it is
straight and not tilted. Remove the two
M20 Allen bolts out of control valve cover
(2) (Fig. 12).
x Insert the control valve cover Allen bolts
(3) and tighten with a 17 mm Allen wrench
(4). Tighten the screws diagonally in
opposed pairs. Refer to chapter 7.9 for
torque values.
7.8
Installing the high pressure
accumulator
x Insert a greased O-ring (1) and back-up
ring (2) in the back of the high pressure
accumulator (3) (Fig. 13).
x Check the condition and function of HeliCoil inserts in the cylinder cover and
replace if necessary.
x If damage is detected to the threads of the
accumulator tension bolts, these should
also be replaced.
x Lubricate the threads of the accumulator
tension bolts with Slip-kote molly paste,
install the washers with the taper against
the bolt head and install. Tighten the bolts
diagonally to the value listed in chapter
7.9. (Fig. 14)
37
Fig. 13
Fitting the high pressure accumulator
Fig. 14
Installing the accumulator tension bolts
Repair manual 795CS, 797CS,B and 805CS,B
7.9
Tightening torque values for Hy-Rams 795CS, 797CS,B and 805CS,B
Part No.
Description
Tightening torque
795/797CS,B 805CS,B
size
size
795/797CS,B 805CS,B
680513
Thread adapter
36mm
36mm
150 ft/lbs.
150 ft/lbs.
678793
Accumulator bolt
30mm
30mm
280 ft/lbs.
280 ft/lbs.
658694
Tension bolt pkg.
65mm
658697
Tension bolt pkg.
678755
Breather valve
36mm
36mm
295 ft/lbs.
*
295 ft/lbs.
657330
Nitrogen fill valve
22mm
22mm
96 ft/lbs.
96 ft/lbs.
677954
Valve cover bolt
17mm
17mm
280 ft/lbs.
280 ft/lbs.
677286
Energy rec. plug
12mm
12mm
133 ft/lbs.
133 ft/lbs.
677956
Swivel bolts
10mm
10mm
63 ft/lbs.
63 ft/lbs.
658283
Auto Control Plug
22mm
22mm
221 ft/lbs.
221 ft/lbs.
*
75mm
795CS, 797CS,B and 805CS,B
* Lubricate all threaded surfaces and both sides of the tapered washer with Slip-kote Molly
Paste. Make certain that the lower tension bolt or rod nuts are assembled so that the raised
part numbers face towards the demolition tool end of the hammer. On B models, make sure
thread insert bores are free of trapped oil and lubricate thread inserts with Slip-kote Molly
Paste (included with seal kit). Pre-tighten the tension bolts or rods to 370 ft/lbs. (500 Nm)
using a torque wrench. Finish-tightening in opposing pairs by 120° (2 flats) and again by 180°
(3 flats) using an electric, pneumatic or hydraulic powered wrench.
38
Repair manual 795CS, 797CS,B and 805CS,B
7.10 Installing the percussion
mechanism in the 'CS' box
bracket
x Replace any defective shoulder dampers
(2), guide plates (3), top damper (4) and
dust ring (7) (Chapters 5.5 – 5.8). Fig. 15
x Install the shoulder dampers (2) and guide
plates (3).
x Stand the 'CS' box (1) vertical and secure
it to prevent it from falling over.
x Insert the appropriate lifting eyebolts fully
into the cylinder head, and install the HyRam's percussion mechanism using a
crane/hoist, into the 'CS' box.
Caution!
Never use your hands to check the position of
the damping or guide elements during the
installation of the Hy-Ram's percussion
mechanism in the 'CS' box.
x Remove the lifting eyebolts from the
cylinder head.
x Install the top damper (4).
x Align your placement marks and install the
top mounting bracket.
Caution!
Never insert your fingers into the mounting
bracket fastener bores to check alignment.
Fig. 15
Installing the Hy-Ram percussion
mechanism in the 'CS' box
39
Repair manual 795CS, 797CS,B and 805CS,B
7.11 Installing the demolition tool
x Remove any dirt from the lower bushing
area of the tool holder.
x Lubricate the demolition tool shank (5)
and retainer bar area with Allied Chisel
Paste. Do not allow grease to get onto the
impact surface of the demolition tool or
piston.
x Insert the tool (5) into the wear bushings
with a hoist/crane.
x Install the lower retainer bar seals (4) and
lock pin (2). Drive the lock pin in with a
hand held hammer (1). See Fig. 16.
x Lubricate the two retainer bars (3) with
Allied Chisel Paste and install them in their
bores. It may be necessary to rotate the
demolition tool to allow the retainer bars to
fully seat.
x Insert the upper retainer bar seals (4) and
lock pin (2). Drive the lock pin in with a
hand held hammer (1). See Fig. 16.
Fig. 16
Installing the demolition tool
Caution!
Wear eye protection!
Risk of injury from flying metal splinters!
Requirements for Guardian® versions
x Install the tool wiper (3) over the
demolition tool (1) by hand and snap it into
the groove in the lower bushing (2). Use a
hammer handle (4) to seat the tool wiper
into the groove. Fig. 17
Warning!
Fig. 17
Installing the tool wiper / Guardian® version
The demolition tool may only be installed in
the hammer with the tool wiper removed.
x If the demolition tool (1) is fitted without
first removing the tool wiper (3), the wiper
will be inverted and will no longer be
functional.
40
Repair manual 795CS, 797CS,B and 805CS,B
7.12 Installing the Dust Protector
(Guardian® version)
x Install the demolition tool (3) into the
hammer (see Chapter 7.11).
x Grease the floating ring (2) and the
support ring (4), and insert them in guide
ring (5).
x Align the bores in the guide ring (5) with
the bores in the Guardian® box.
x Insert the locking pins (1).
x Hammer the locking pin into position using
a punch and a hand held hammer.
Caution!
Wear eye protection!
Risk of injury from flying metal splinters.
Fig. 18
Installing the Dust Protector / Guardian®
version
41
Repair manual 795CS, 797CS,B and 805CS,B
7.13 Filling the nitrogen pre-charge
chamber
Caution!
The nitrogen pre-charge chamber may only
be filled with nitrogen. Filling with air or
oxygen runs the RISK OF AN EXPLOSION.
When filling the nitrogen pre-charge chamber,
ensure no one is standing in the area of the
demolition tool. If the tool has jammed, it may
shoot out of the lower hammer part a few
inches.
The required pressure in the nitrogen precharge chamber is:
Model
Gas pressure Gas pressure
at 70qF (21q C) at 150qF (66q C)
795CS
172 psi (12 bar)
200 psi (14 bar)
797CS,B 198 psi (14 bar)
230 psi (16 bar)
805CS,B 141 psi (10 bar)
165 psi (12 bar)
Please note!
When filling the nitrogen pre-charge chamber,
the hammer must be lying flat with no contact
pressure applied to the demolition tool. Filling
can be performed with the hammer cold or at
operating temperature.
x Refer to the appropriate setting for the
temperature of the hammer being filled.
x Remove the fill valve plug (5) out of the fill
valve “G”.
x Adjust the regulator handle counter
clockwise until little resistance is felt.
x Insert nozzle (2) of the fill hose into the fill
valve (“G”) on cylinder head and hold.
x Open the nitrogen cylinder valve slowly.
x Adjust the regulator handle clockwise until
the specified pressure has been achieved.
x After a few minutes, close the valve on the
nitrogen cylinder and monitor the gauge
on the regulator. Add more gas if
necessary as directed above.
x Remove the fill hose (2).
x Connect the test gauge and double-check
the pre-charge pressure. If the nitrogen
pre-charge reading is below the reference
pressure, repeat the filling process.
x Reinstall the fill valve plug (5).
Fig. 1
Filling the nitrogen pre-charge chamber
G
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Repair manual 795CS, 797CS,B and 805CS,B
7.14 Charging the high pressure
accumulator
x Assemble the accumulator charge kit P/N
657604 (1) as shown (Fig. 1) to a dry
nitrogen gas cylinder (green).
x Remove the protective cover from the top
of the accumulator.
x Slide the charge tool over the accumulator
fill nozzle and rotate the clamp (4) counter
clockwise to tighten the charge assembly
onto the accumulator.
x Engage the Phillips bit into the screw head
and loosen the screw 3-5 turns with the 'T'
handle (2).
x Close the vent (3). (Rotate the knob
clockwise)
x Rotate the pressure regulator adjustment
counter clockwise to the lowest setting.
x Open the valve slowly on the nitrogen
cylinder.
x Adjust the regulator handle clockwise to
the specified pressure of 60 bar (870
psi.). Allow 30 – 60 seconds for the
accumulator to fill.
x Tighten the Phillips head screw by rotating
the 'T' (2) handle clockwise.
x Close the valve on nitrogen gas cylinder.
x Open the vent (3). (Rotate the knob
counter clockwise)
x Loosen the clamp (4) (clockwise) and
remove the charge tool.
x Check for leaks around the Phillips head
screw with liquid.
x Install protective covers.
Caution!
The nitrogen pre-charge chamber may only
be filled with nitrogen. Filling with air or
oxygen runs the RISK OF AN EXPLOSION.
43
2
1
3
4
Fig. 1
Charging the high pressure accumulator
Repair manual 795CS, 797CS,B and 805CS,B
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