TM-9-2320-283-20-1

TRUCK TRACTOR, LINE HAUL, 50,000 GVWR, 6X4, M915A1

TECHNICAL MANUAL; ORGANIZATIONAL MAINTENANCE PART 1 OF 3

DECEMBER 1983

TM-9-2320-283-20-1 - Page 438 of 926

TM 9-2320-283-20-1

TROUBLESHOOTING.

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

119.

SERVICE BRAKES ARE UNEVEN OR ERRATIC ON ONE OR MORE WHEELS (Continued).

Step 2.

Loosen line fitting at affected wheel air chamber and have an assistant lightly depress brake pedal.

Listen

for air exhausting from line.

No air indicates a clogged line.

Replace damaged or clogged line.

Step 3.

Check brake adjustment (para 3-157).

Step 4.

Press brake pedal down and listen for air leakage around wheel air chamber clamp.

Tighten clamp or replace brake chamber (para 3-165 for front brakes, para 3-165 or 3-166 for

rear brakes).

Step 5.

Remove drum to inspect (para 3-204 or 3-206).

a. Clean, repair, or replace defective brake components (para 3-158 thru 3-162).

b. Check brake shoes (linings) for grease, glazing, and proper installation (para 3-159).

120.

BRAKES OVERHEAT.

Step 1.

Check for low reservoir pressure.

If below 70 psi, see malfunction 107 (forward-rear axle only).

Step 2.

Check for damaged or leaking front ratio valve or rear relay valves.

Tighten loose connections or replace defective valve (para 3-181 or 3-177, as applicable).

2-312