TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
68.
REAR BRAKES DO NOT WORK - CONTINUED
NOTE
Check AIR PRESSURE gage for air pressure between 90 and 130 psi. If specified air pressure is
not present, start engine and check that air pressure in air system is between 90 and 130 psi (TM
5-3805-254-10). Shut down engine (TM 5-3805-254-10).
Step 11.
Check operation of four rear wheel brakeshoes (1) as follows: using flashlight, look at brakeshoes
(1) through two inspection holes (2) in backing plate (3). Have assistant apply pedal (4) several
times and check for free movement of brakeshoes (1).
a. If brakeshoes (1) do not operate, go to step 12.
b. If brakeshoes (1) do not release from drums, go to Malfunction 66, AIR BRAKES DO
NOT RELEASE (page 2-346).
Step 12.
Check adjustment of rear brakeshoes (1) as follows: Using feeler gage, .025inch (.635 mm),
measure distance between rear brakeshoes (1) and drum (5).
a. If rear brakeshoes (1) are more than .025-inch (.635 mm) away from drum (5), adjust
rear brakes (page 2-973).
b. If rear brakeshoes are adjusted to .025-inch (.635 mm) from drum (5), go to step 13.
WARNING
Parts of brake assembly will be coated with asbestos dust. Breathing this dust may be hazardous
to your health. Use filter mask approved for use against asbestos dust. Never use compressed
air or dry brush to clean these assemblies. Dust shall be removed using industrial type vacuum
cleaner equipped with high efficiency filter system. Clean dirt or mud from brake assemblies with
bristle brush or cloth, and water.
When jacking vehicle, make sure and support vehicle with trestle stands to prevent personnel
injury. Chock wheels to prevent undue movement of vehicle.
Step 13.
Jack up rear of dump truck (page 2-424). Check rear brakeshoes (1) and mounting hardware for
damage as follows: inspect brake spring (6) and clips (7) for cracked, bent, broken, or stretched
coils or distorted ends. Inspect brake rollers (8) for deep grooves or excessive wear. Inspect
brakeshoes (1) for oil soaked, cracked, burned, or chipped lining (9). Using tire tread depth gage,
check that lining (9) thickness is more than 1116-inch (1.6 mm) above rivets (10).
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