Parking Brake System: Testing and Inspection

PARKING BRAKE SHOES AND DRUM 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. Use an OSHA-Approved vacuum cleaner.

NOTE:
- Contaminated brake linings or drums reduce stopping ability.
- Block the front wheels before raising the rear of the vehicle.

1. Raise the rear of the vehicle, and make sure it is securely supported.

2. Release the parking brake, and remove the rear caliper and rear brake disc/drum.





3. Check the parking brake linings (A) for cracking, glazing, wear, and contamination.
4. Measure the parking brake lining thickness (B). Measurement does not include brake shoe thickness.

Parking Brake Lining Thickness:
Standard: 1.9 - 2.5 mm (0.075 - 0.098 inch)
Service Limit: 1.0 mm (0.04 inch)

5. If the brake lining thickness is less than the service limit, replace the parking brake shoes as a set.
6. Check the bearings in the hub unit for smooth operation.





7. Measure the inside diameter of the parking brake drum brake with inside vernier calipers.

Parking Brake Drum Inside Diameter:
Standard: 169.9 - 170.0 mm (6.689 - 6.693 inch)
Service Limit: 171.0 mm (6.732 inch)

8. If the inside diameter of the parking brake drum is more than service limit, replace the rear brake disc/ drum brake.
9. Check the parking brake drum brake for scoring, grooves, and cracks.