TM-9-2320-285-24-1

TRUCK TRACTOR, YARD TYPE, 43,500 LB GVW, DED, 4X2, ARMY MODEL M878A1

TECHNICAL MANUAL; ORGANIZATIONAL, DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL

OCTOBER 1985

TM-9-2320-285-24-1 - Page 547 of 987

TM 9-2320-285-24-1

2-46.

SERVICE BRAKE SYSTEM TROUBLESHOOTING (CONT)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

5.

FRONT AXLE BRAKES DRAGGING (Cont)

Step 4.

Remove plungers (para 2-50a).

Check plungers for corrosion, inadequate lubrication, or sticking.

Check seals for damage.

a.

If plungers are corroded, replace (para 2-50a); if plungers are

inadequately lubricated, lubricate (para 2-50a); if plungers do

not slide freely in respective bores in spider, replace (para

2-50a).

Replace seals (para 2-50a).

b.

If plungers are adequately lubricated and are not corroded or

sticking, and seals are not damaged, go to step 5 below.

Step 5.

Check brake shoe linings for grease or dirt contamination.

a.

If brake shoe linings are contaminated, replace brake shoes (para 2-50a).

b.

If brake shoe linings are not contaminated, go to step 6 below.

Step 6.

Check front axle brakes air chambers for damage.

a.

If front axle brakes air chambers are damaged, replace or repair (para 2-51d(1)).

b.

If front axle brakes air chambers are not damaged, go to step 7 below.

Step 7.

Check air brake system lines and fittings for air leaks.

a.

If lines are leaking air, repair or replace (para 2-51a).

b.

If fittings are leaking air, tighten.

If fitting leaks after tightening, replace (para 2-51a).

6.

REAR AXLE BRAKES DRAGGING

Step 1.

Check wheel bearing for proper adjustment (raise wheel and use pry bar to check for any noticeable

end play) or damage.

Repeat for other wheel.

a.

If end play is noticeable, adjust or replace wheel bearing (para 2-44b).

b.

If end play is not noticeable, go to step 2 below.

2-524