TM-9-2320-361-20

2-1/2-TON, 6x6, M44A2 SERIES TRUCKS (MULTIFUEL)

TECHNICAL MANUAL; UNIT MAINTENANCE

OCTOBER 1991
TM-9-2320-361-20

  TM-9-2320-361-20 - Page 141 of 1207

TM 9-2320-361-20
Table 2-3. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR lNSPECTION
CORRECTIVE ACTION
SERVICE BRAKES
WARNIN G
Ensure new longer front brake hoses, currently used on 5-ton
trucks, are installed on all 2-1/2-ton trucks. Old shorter front brake
hoses are subject to failure during full steering travel and must be
replaced with new longer front brake hose. Failure to do this may
result in injury or death to personnel.
NOTE
Old shorter front brake hoses should be replaced with new longer
front brake hoses (para. 8-16).
3. BRAKE PEDAL LOW, SOFT, OR GOES TO FLOORBOARD (WEAK OR NO BRAKING)
Step 1. Check master cylinder fluid level.
If fluid level is low, fill to proper level (LO 9-2320-209-12-1).
Step 2. Check wheel cylinders (2), hydraulic brake lines (1), and hoses for leaks, cracks, breaks, or
loose connections.
a. If hydraulic brake lines (1) or hoses are loose, tighten.
b. If hydraulic brake lines (1) or hoses are broken, cracked, or leaking, replace (para. 8-15,
8-16, or TM 9-243).
c. If wheel cylinders (2) are leaking, replace (para. 8-9).
Step 3. Check for air in service brake system.
Bleed service brake system (para. 8-12).
Step 4. Check service brake hydraulic fluid for contamination.
If fluid is contaminated, flush entire brake system (para. 8-12).
Step 5. Check service brakeshoes (3) for proper adjustment and check service brakeshoe (3) linings
for wear.
a. Adjust service brakeshoes (3) if necessary (para. 8-8).
b. If service brakeshoe (3) linings are worn more than 0.328 in. (8.33 mm), replace
(para. 8-7).
Step 6. Remove two screws (6) and shield (7) from air-hydraulic cylinder (4).
Step 7. Inspect master cylinder (5) for leaks.
If master cylinder (5) is leaking, replace (para. 8-10).
Step 8. Inspect air-hydraulic cylinder (4) for brake fluid leaks.
If air-hydraulic cylinder (4) is leaking brake fluid, replace (para. 8-11).
Step 9. Perform master cylinder (5) internal leakage test (para. 8-10).
a.
b.
If master cylinder (5) is leaking internally, replace (para. 8-10).
If master cylinder (5) is good, and malfunction still exists, replace air-hydraulic
cylinder (4) (para. 8-11).
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