TRAINING AND EQUIPMENT MANUAL
310 APPARATUS
310.001 AIR-BRAKE SYSTEM INSPECTION
EFFECTIVE: OCTOBER 2007
PURPOSE
The purpose of this policy is to instruct members on the correct procedures for
checking air-brake systems.
APPLICATION
It is the policy of the Department all front-line emergency response apparatus
equipped with air-brake systems will have these systems inspected on a daily basis.
Note: For information on checking Department response vehicles with
hydraulic-brake systems, refer to Training and Equipment
Manual,
Section
310.001a,
Hydraulic-Brake
System
Inspections.
INFORMATION
Routine monitoring of air-brake systems may assist in indicating existing or potential
brake problems such as broken or cracked brake drums and rotors, broken or
ineffective brake springs, excessive lining wear, marginal or defective valves, air
chambers, etc.
There are two basic designs of air-brake systems used on Department apparatus:
‘S’ cam (Figure 1) and disc (Figure 2). Some apparatus may be equipped with disc
brakes on the front axle and ‘S’ cam on the drive axle.
To ensure proper operation and to determine if the brakes are within acceptable
adjustment tolerance, air-brake systems shall be checked daily in accordance with
this policy.
Revised 06/13/11
Section 310.001
Page 1 of 8
Figure 1: ‘S’ Cam
Figure 2: Disc
BRAKE TESTS
Department policy requires all air tank reservoirs to be drained weekly. In addition to
draining the tanks, there are 11 brake tests identified by the California Commercial
Drivers Handbook (CCDH), which must be completed daily. Brake tests should be
performed outside whenever possible and in a well-ventilated area. A synopsis of
the 11 brake tests and the air tank reservoir draining process follows:
1. (C) Governor Cut-In: Not lower than 85 psi.
2. (O) Governor Cut-Out: 110 to 130 psi.
3. (L) Low-Pressure Warning: 60 psi.
4. (A) Service Air Leakage (Applied Test): Less than three psi in one
minute.
Note: COLA = Items that must be demonstrated during DMV
testing.
5. Reservoir Leakage (Static Test): Less than two psi in one minute.
6. Park Brake Valve: Push/pull valve operates between 20 and 45 psi.
7. Inspection: Inspect brake drums, disks, linings, and hoses.
8. Rate of Air Pressure Buildup: 85 up to 100 psi within 45 seconds.
9. Brake Service: Service brake application at five mph.
10. Park Brake Test: Must stop vehicle while rolling below five mph.
11. Check Adjustment: Brake adjustment check at 90 psi.
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Section 310.001
Page 2 of 8
Draining Air Tank Reservoirs
Air tank reservoirs of all apparatus equipped with air brakes shall be drained and
refilled to operating air pressure during the weekly emergency equipment (FD-011)
checks.
1. Open drain/petcock slowly.
2. Expel moisture from the tank.
3. Once no remaining moisture is visible, open drain/petcock fully and
drain tank.
4. Close drain/petcock and refill air tank reservoirs to operating
pressures.
Test 1 – Governor Cut-In Test
1. Start with engine idling and parking brake set.
2. Pump brake slowly to reduce air reservoir pressure.
3. Watch the air pressure gauge to note when the compressor cuts in.
4. Pressure should begin to build at or above 85 psi.
Test 2 – Governor Cut-Out
1. Continued from Test 1.
2. Using fast idle is OK and may reduce pressure build-up time.
3. Governor should cut out at correct pressure (110 to 130).
Test 3 – Low-Pressure Warning
1. Make light brake applications until pressure drops below 60 psi.
2. Low-pressure warning light or buzzer should go on at or above
60 psi.
Note: Engine stopped, ignition on, park brake off, wheels
chocked.
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Section 310.001
Page 3 of 8
Test 4 - Reservoir Leakage
1. Allow pressure to stabilize for at least one minute.
2. Observe the dash gauge pressures for one minute.
a. A pressure drop of two psi within one minute is allowable for
either service reservoir.
Note: Foot brake released, engine stopped, parking
brakes applied.
Test 5 – Service Air Leakage
1. Make and hold brake application.
2. Allow pressure to stabilize for one minute, begin timing for one
minute while watching the gauges for a pressure drop. A pressure
drop of three psi within one minute is allowable for either service
reservoir.
Note:
Full reservoir pressure, engine stopped, parking brakes
released.
Test 6 – Park-Brake Valve
1. Make light brake applications until push/pull valve pops out. The
normal limits are between 20 and 45 psi.
Note:
Full reservoir pressure, engine stopped, parking brake
off, wheels chocked.
Test 7 – Inspection Test
1. Free of oil and grease.
2. Minimum 1/4 inch of brake shoe material.
3. No significant cracks.
4. Check general condition of all components.
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Section 310.001
Page 4 of 8
Test 8 – Rate of Air Pressure Build-up
1. Parking brake set.
2. Engine at fast idle.
3. Pump brake to drop pressure below 85 psi.
4. Pressure should build from 85 to 100 psi within 45 seconds.
Test 9 – Service Brake Application
1. Full air brake psi in system.
2. While traveling approximately five mph, apply brakes firmly.
3. Check for pulling to one side, unusual feel or sound.
Test 10 – Parking Brake Test
1. Place the transmission in a forward-drive mode.
2. Allow vehicle to move slowly forward (under five mph) and apply the
parking brake.
3. If vehicle fails to stop, the parking brake is not operating properly
and needs attention.
Test 11 – Brake Adjustment Check
‘S’ Cam Systems:
1. Chock wheels.
2. Release parking brake.
3. Make light brake applications until pressure gauge reads 90 psi.
4. Make and hold a brake application. Have assistant measure brake
chamber and push rod travel. Allowable tolerances are listed
below:
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Section 310.001
Page 5 of 8
a. 24-inch brake pod = 1-3/4 inches maximum allowable travel
distance.
b. 30-inch brake pod = 2 inches maximum allowable travel
distance.
5. The automatic self-adjusting slack adjuster on ‘S’ cam brakes is
designed to self-adjust at maximum travel distance. If the push rod
travel distance is deemed more than the maximum travel distance,
the driver shall attempt to adjust the brakes by: first, chock the
apparatus and release the parking brake; next, allow air pressure to
build to cut-out pressure; to complete the process, make several
stabbing full-brake (to the floor with the brake pedal) applications.
Allow for the air compressor to build again to cut-out pressure and
repeat the brake applications a second time (Figure 4).
Brakes not applied
Figure 4
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Section 310.001
Page 6 of 8
Brakes applied
Figure 5
6. Again, measure the push rod travel distance for allowable
tolerances (Figure 5).
7. If the travel distance remains out of adjustment, place the apparatus
out of service and contact the Repair and Maintenance Shop.
Disc Brake Systems:
1. The brake slack adjuster (push rod travel) is measured the same
way as described for ‘S’ Cam systems.
2. To check for lining wear, check the position of the inboard bosses of
the caliper on the slide pins. If the bosses are within 1/4 inch
(6.4 mm) of the ends of the slide pins, submit repair requisition
noting, "slide pin showing 1/4 inch; pads need replacing." If the
bosses are within 1/8 inch (3.2 mm) of the ends of the pins, notify
the shop immediately via telephone. The arrow on the following
picture points to the slide pin within the inboard boss of a disc brake
caliper (Figure 6).
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Section 310.001
Page 7 of 8
Figure 6
In the event the braking system fails any of the above criteria, the company officer
shall immediately place the apparatus out of service, and notify his/her respective
battalion chief and the Repair and Maintenance Shop for instructions.
Refer to Training and Equipment Manual, Section 310.009 for additional out-ofservice criteria.
Completion of the test procedure, together with the results of the test, shall be noted
on the Pre-Trip Inspection Report (FD-03) and the Weekly Inspection of Equipment
(FD-11).
CROSS REFERENCES
California Commercial Driver Handbook
Title13 of the California Code of Regulations, Article 1245 (K)
Administrative Manual
Section 106.023 Pre-Trip Inspection Report (FD-03)
Section 106.029 Weekly Inspection of Emergency Equipment (FD-11)
Training and Equipment Manual
Section 310.001a, Hydraulic Brake System Inspections
Section 310.009, Pre-Trip Inspection
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Section 310.001
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