SERVICE BRAKES FAIL TO RELEASE OR RELEASE SLOWLY.

TM 9-2320-279-20-1

Troubleshooting Malfunctions (Cent)

12-15. TROUBLESHOOTING INSTRUCTIONS

Table 2-9. Troubleshooting

Malfunction

Test or Inspection

Corrective Action

DUAL AIR BRAKE SYSTEM

3. SERVICE BRAKES FAIL TO RELEASE OR RELEASE SLOWLY.

Step 1. Check brake adjustment.

If brakes are out of adjustment, adjust brakes (para 11-7).

Step 2. Check for defective service brake relay valve, Start engine and build up air pressure. Apply

and release service brake. Carefully remove air line from service port of service brake relay

valve.

11-12).

If air escapes, replace service brake relay valve

Step 3. Remove brake drum. Check S-cams and other moving brake parts for binding or damage.

If binding or damage is found, lubricate or replace damaged brake parts (para 11-3,

11-4, 11-5, or 11-6).

BRAKES GRAB WHEN APPLIED.

Step 1. Check brake adjustment

11-7).

Adjust brakes (para 11-7).

Step 2. Remove brake hub and drum assembly (para 12-2). Check for worn, glazed, or

contaminated brake linings.

Replace worn, glazed, or contaminated brake shoes

11-3 or 11-4).