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 436 of 926

TM 9-2320-283-20-1

TROUBLESHOOTING.

2-11.

TROUBLESHOOTING PROCEDURES (Continued).

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

117.

FRONT SERVICE BRAKES ARE WEAK OR SLOW WORKING (Continued).

Step 3.

Check brake pedal valve for damage and leakage using a soap solution.

Replace defective valve (para 3-174).

Step 4.

Check front brakes for worn linings (shoes) and proper adjustments.

Adjust brakes and replace linings, if necessary (para 3-157 or 3-159).

118.

REAR SERVICE BRAKES ARE UNEVEN OR ERRATIC.

Step 1.

Check for leakage in air lines between service brake relay valve and wheel air chambers using a soap

solution.

Step 2.

Check for air leakage between air reservoir and rear service brake relay valve.

Tighten loose connections or replace damaged lines.

Step 3.

Leak test rear brake part of the brake treadle valve.

Tighten loose connections or replace brake treadle valve (para 3-174)

Step 4.

Check brake shoes for proper adjustment.

Adjust brake shoes (para 3-157).

119.

SERVICE BRAKES ARE UNEVEN OR ERRATIC ON ONE OR MORE WHEELS.

Step 1.

Have an assistant press and hold brake pedal down and perform leakage test on air lines at affected wheels

using a soap solution.

2-310