TRAILER BRAKE SYSTEM FAILS OR BRAKING WEAK.

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Table 3-5. Troubleshooting (Cont)

Malfunction

Test or Inspection

Corrective Action

BRAKES AND AIR SYSTEM (CONT)

Step 9. Disconnect hook switch leads (11) from front disc brake pad indicator wiring

harness (12) at both front brake assemblies (13) and check if brake indicator

light is lit.

If brake indicator light is lit, replace front disc brake pad

indicator wiring harness (page 4-231).

If brake indicator light is not lit, go to step 10.

Step 10. With hook switch leads (11) disconnected, check continuity between hook

switch leads and ground.

Replace hook switch that shows short to ground.

88. TRAILER BRAKE SYSTEM FAILS OR BRAKING WEAK.

NOTE

Brake lever must be fully actuated and dual brake gage indicating normal pressure.

Step 1. Check for leaking and damaged brake hose couplings.

If brake hose couplings are leaking or damaged, tighten or

replace couplings (page 4-324).

If brake hose couplings are not leaking or damaged, go to

step 2.

Step 2. Check for air leaks around trailer air supply valve.

If there are air leaks around trailer air supply valve, replace

trailer air supply valve (page 4-331).

If there are no air leaks around trailer air supply valve, go to

step 3.

Step 3. Check for air leaks around trailer hand brake valve.

If there are air leaks around trailer hand brake valve, replace

trailer hand brake valve (page 4-326).

If there are no air leaks around trailer hand brake valve, notify

direct support maintenance.

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