Table 4-2. Unit Troubleshooting (cont'd)
TEST OR INSPECTION
Step 5. Test air lines for leakage.
If air lines leak, repair or replace air lines as needed.
If air pressure is normal and air lines are not restricted or leaking, proceed to step 6.
Step 6. Check for defective relay valve.
If valve is defective, replace relay valve.
If valve is not defective, proceed to step 7.
Step 7. Check for defective brake chamber.
If brake chamber is defective, replace brake chamber.
If brake chamber is not defective, proceed to step 8.
Step 8. Check for grease on brake lining.
Replace defective oil seal (para. 4-52 (XM1063) or 4-53 (M129A4)) and brake shoes
If grease is not present on brake lining, proceed to step 9.
Step 9. Check for worn brake lining.
If brake lining is worn, replace brake shoes (para. 4-55).
If brake lining is not worn, proceed to step 10.
Step 10. Check for brake adjustment.
Adjust brakes if out-of-adjustment (para. 4-50 (XM1063) or 4-51 (M129A4)).
12. SLOW BRAKE APPLICATION OR SLOW RELEASE
Step 1. Check for restrictions in air lines and hoses.
If air lines or hoses are restricted, replace as required.
If air lines and hoses are not restricted, proceed to step 2.
Step 2. Check relay valve operation.
If relay valve is defective, replace relay valve.
If relay valve is not defective, proceed to step 3.