Rear Drum Brake: Inspection
CAUTION:
Frequent inhalation of brake pad 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.
NOTE:
- Contaminated brake linings or drums reduce stopping ability.
- Block the front wheels before jacking up the rear of the vehicle.
- Raise the rear of the vehicle, and make sure it is securely supported.
- Release the parking brake, and remove the rear brake drum.
- Check the wheel cylinder (A) for leakage.
- Check the brake linings (B) for cracking, glazing, wear, and contamination.
- Measure the brake lining thickness (C). Measurement does not include brake shoe thickness.
Brake lining thickness
Standard: 3.9-4.5 mm (0.15-0.177 in.)
Service limit: 1.0 mm (0.039 in.)
- If the brake lining thickness is less than the service limit, replace the brake shoes as a set.
- Check the bearings in the hub unit for smooth operation. If it requires servicing, replace it.
- Measure the inside diameter of the brake drum with inside vernier calipers.
Drum inside diameter
Standard: 203.2 mm (8.0 in)
Drum roundness
Service limit: 0.06 mm (0.00236 in)
- If the inside diameter of the brake drum is more than the service limit, replace the brake drum.
- Check the brake drum for scoring, grooves, and cracks.
- Inspect the brake lining and drum for proper contact.
- Inspect the wheel cylinder outside for excessive wear and damage.
- Inspect the backing plate for wear or damage.