UNIT TROUBLESHOOTING - CONTINUED
TEST OR INSPECTION
10. BRAKES GRAB OR ARE LOCKED - ONE WHEEL
If wheel is locked, go to step 1. If brake is grabbing on affected wheel, go directly to step 2.
Step 1. Check brake adjustment (page 4-119).
Adjust brake on locked wheel to free it. If unable to free wheel, go on to b.
If rear wheel is affected, check operation of spring brake unit.
Release spring brake unit manually as per instructions on data plate on
If spring brake unit cannot be released manually, replace spring brake unit.
If spring brake unit is released, go on to step 2.
If rear wheel is not affected, go on to step 2.
Step 2. Check for malfunction in service brake assembly (page 4-103).
Check service brake assembly for:
Cracked, broken, worn, loose, or contaminated linings.
Frozen wheel bearings.
Broken return spring(s).
Cracked, scored, or deformed brake drum.
Repair service brake assembly (page 4-103).
Step 3. Refer to Section IX for additional brake system maintenance information.