Brake Drum: Testing and Inspection

Rear Drum Brake Inspection

CAUTION
Frequent inhalation of brake shoe dust, regardless of material composition, could be hazardous to your health.
- Avoid breathing dust particles.
- Never use an air hose or brush to clean brake assemblies. Use an OSHA-approved vacuum cleaner.


1. Raise and support the vehicle Service and Repair.

2. Remove the rear wheels.

3. Release the parking brake, and remove the brake drum.






4. Check the wheel cylinder (A) for leakage.






5. Check the brake linings (B) for cracking, glazing, wear, and contamination.

NOTE: Contaminated brake linings or drums reduce stopping ability.

6. Measure the brake lining thickness (C). Measurement does not include brake shoe thickness.





7. If any part of the brake lining thickness is less than the service limit, replace the brake shoes as a set.

8. Check the hub (D) for smooth operation. If it requires servicing, replace the hub bearing unit Rear Hub Bearing Unit Replacement.

9. Measure the inside diameter of the brake drum with inside vernier calipers.










10. If the inside diameter of the brake drum is more than the service limit, replace the brake drum.

11. Install the brake drum.

12. Check the brake drum for scoring, grooves, corrosion, and cracks.

13. Clean the mating surfaces between the brake disc and the inside of the wheel, then install the rear wheels.