SERVICE BRAKES GRAB

TM 10-3930-638-24&P

2-41. BRAKE SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

4. SERVICE BRAKES GRAB

Check source of brake fluid to ensure that brake fluid is correct; also check for contaminated brake

Step 1.

fluid.

a. If incorrect brake fluid was used or if brake fluid is contaminated, drain brake system of brake

fluid and refill using correct brake fluid (refer to current lubrication order) (para 2-43a).

b. If brake fluid is okay, proceed to step 2.

Check brake pedal/return spring linkage for binding, interference, missing parts, or damage (para 2-43e).

Step 2.

a. If brake pedal/return spring linkage is binding, has interference, is missing parts or damaged, repair

b. If brake pedal/return spring are okay, proceed to step 3.

Step 3. Check hydraulic brake valve for damage/leaking condition (para 2-43c).

a. If hydraulic brake valve is damaged or leaking, repair or replace it (para 2-43c).

b. If hydraulic brake valve is okay, proceed to step 4.

Step 4. Place blocks (6 by 6 by 18 inches wood blocks) at each wheel to prevent vehicle from moving.

Remove shipping lock pin from storage area under operator's seat (para 2-4b(1)) and install in chassis.

Ensure that parking brake is in released position.

WARNING

Before raising axle off ground, be sure that shipping lock pin is installed.

Failure to do so may cause vehicle to turn and slip off jack or jack stands

causing serious injury or death. If you are injured by falling equipment,

obtain medical aid immediately.

Raise one axle and wheels off ground.

Rotate wheel by hand; there should be a very slight dragon wheel.

Repeat above for remaining wheel and axle.

a. If there is a very slight drag on wheels, proceed to step 5.

b. If there is excessive dragon wheels, adjust brakes (para 243a).

Step 5. Remove axle shafts and hub and drum assemblies from one axle (para 2-39f).

Check brake shoe return spring (para 243a).

Repeat above for remaining axle.

a. If brake shoe return spring is permanently set, replace (para 2-43a).

b. If brake shoe return spring is okay, proceed to step 6.