Parking Brake System: Testing and Inspection
InspectionWARNING:
- Never use an air hose or dry brush to clean brake assemblies.
- Use an OSHA-approved vacuum cleaner to avoid breathing brake dust.
- Contaminated brake linings or drums reduce stopping ability.
- Block the front wheels before jacking up the rear of the vehicle.
1. Block the front wheels, loosen the rear wheel nuts slightly, support the rear of the vehicle on safety stands, then remove the rear wheels.
2. Remove the rear caliper and rear brake disc/drum.
3. Check the brake linings for cracking, glazing, wear, and contamination.
4. Measure the brake lining thickness.
NOTE: Measurement does not include brake shoe thickness.
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 brake shoes as a set.
6. Check the bearings in the hub unit for smooth operation.
7. Measure the inside diameter of the disc/drum using inside vernier calipers.
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 brake disc/drum is more than the service limit, replace the brake disc/drum.
9. Check the brake disc/drum for scoring, grooves, and cracks.