SERVICE BRAKE SYSTEM TROUBLESHOOTING

TM 9-2320-285-24-1

2-46.

SERVICE BRAKE SYSTEM TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. FRONT OR REAR AXLE BRAKES RELEASE SLOWLY

Check air brake system for obstructed lines and fittings.

WARNING

Compressed air must not exceed 30 psi. Wear safety glasses when using compressed air.

Failure to do so could cause serious injury to eyes and possible blindness. If you hurt your

eyes or if a foreign object is blown into your eyes, seek medical aid immediately.

a. If lines or fittings are obstructed, clear using compressed air

(30 psi maximum) in reverse of normal air flow. If line or

fitting remains obstructed, replace (para 2-51a).

b. If lines and fittings are not obstructed, notify direct support maintenance.

2. UNEVEN OR ERRATIC FRONT AXLE BRAKES

Step 1.

Check if air pressure in each tire is 120 psi.

a. If air pressure in tire is not 120 psi, adjust tire pressure.

b. If air pressure in each tire is 120 psi, go to step 2 below.

Step 2.

Check brake drum-to-lining clearance (para 2-50a).

a. If clearance is excessive, adjust brakes (para 2-50a); then

retest for proper operation. If front axle brakes operation

remains uneven or erratic, go to step 3 below.

b. If clearance is not excessive, go to step 3 below.

Step 3.

Remove brake drums (para 2-44a).

Check brake shoe linings for wear, uneven glaze, lubricant contamination, or excessive dust.

WARNING

Brake linings contain asbestos fibers. Do not generate dust when working on brake system.

Do not remove dust or dirt with compressed air because serious bodily harm may result from

breathing asbestos dust.

a. Replace brake shoe linings if worn, glazed, or contaminated (para 2-50a); remove excessive

dust.

2-520