Brake Shoe: Service and Repair

BRAKE SHOES









Removal

WARNING:Asbestos fiber dust can be present on brake and clutch assemblies and is hazardous to health if inhaled. Failure to follow these instructions may result in personal injury.Brake and clutch assemblies must be cleaned using a vacuum cleaner recommended for use with asbestos fibers, such as a Brake/Clutch/Service Vacuum. The bag must be labeled per occupational safety and health act (OSHA) instructions, sealed, and the trash hauler notified as to the bag's contents. Failure to follow these instructions may result in personal injury.

WARNING:If a vacuum suitable for asbestos is not available, cleaning must be done wet. If dust generation is still possible, technicians must wear government-approved toxic dust purifying respirators. Failure to follow these instructions may result in personal injury.OSHA requires areas where asbestos dust generation is possible to be isolated and posted with warning signs. Only technicians performing brake or clutch repair are to be present in the area. Failure to follow these instructions may result in personal injury.

WARNING:To reduce the possibility of uneven braking, always install new rear brake shoes and linings at both ends of an axle.
NOTE:Make sure that the parking brake control is fully released.
1. Remove the brake drum. See Service and Repair.

2. Inspect the rear brake assembly.

- Inspect the wheel cylinder for excessive leakage that can contaminate brake system parts and install a new wheel cylinder as necessary.
- Inspect the brake shoes and linings for contamination and install new shoes and linings as necessary.
- Inspect the brake shoes and linings for minimum thickness, above the backing plate or rivets and install new as necessary.
- Inspect the springs for heat discoloration and install new as necessary.
- Inspect the adjusting lever contact with the brake adjuster screw.

3.
NOTE:To aid installation, note the locations of the short and long brake shoe retracting springs.Remove the brake shoe retracting springs.

4. Remove the adjusting screw assembly in the following sequence.

- Disconnect the brake shoe adjusting lever cable from the brake shoe adjusting lever.
- Remove the brake shoe adjusting lever cable.
- Remove the cable guide.
- Remove the adjusting lever return spring and the brake shoe adjusting lever.
- Remove the brake shoe adjusting screw spring.
- Remove the brake adjuster screw assembly.

5. Remove the brake shoe anchor pin guide plate and the parking brake strut.

6. Remove the hold-down springs and the rear brake shoes and linings.

- Remove the brake shoe hold-down spring pins.

7. Pull back the parking brake cable spring and disconnect the parking brake lever.

Installation

1. Compress the parking brake cable spring and attach the parking brake lever.






1. Clean and lubricate the brake backing plate using silicone brake caliper grease or an equivalent silicone.

2. Install the rear brake shoes and linings in the following sequence.
1 Position the rear brake shoes and linings.
2 Position the parking brake lever.
3 Install the brake shoe hold-down spring pins and the brake shoe hold-down springs.

3. Install the parking brake strut in the following sequence.
1 Install the parking brake link spring on the parking brake strut.
2 Install the parking brake strut.
3 Install the brake shoe anchor pin guide plate.

4. Install the short brake shoe retracting spring in the following sequence.
1 Place the brake shoe adjusting lever cable over the anchor pin, with crimped side in.
2 Install the short brake shoe retracting spring.

5.
NOTE:Make sure the brake shoe adjusting lever cable is positioned in the cable guide groove.Install the long brake shoe retracting spring in the following sequence.
1 Install the cable guide.
2 Position the brake shoe adjusting lever cable in the cable guide groove.
3 Install the long brake shoe retracting spring.

6.
NOTE:To prevent incorrect installation, the socket end of each brake adjuster screw is stamped R or L.Assemble the brake adjuster screw assembly in the following sequence.
1 Apply silicone brake caliper grease to the threads on the brake adjuster screw.
2 Install the brake adjuster screw into the brake shoe adjusting screw nut to the end of the threads, and then loosen one-half turn.
3 Install the brake shoe adjusting screw socket on the brake shoe adjusting screw nut.

7. Install the brake adjuster screw assembly in the following sequence.
1 Position the brake adjuster screw assembly.
2 Install the brake shoe adjusting screw spring.
3 Position the brake shoe adjusting lever cable.
4 Position the adjusting lever return spring and the brake shoe adjusting lever.
5 Hook the brake shoe adjusting lever cable to the brake shoe adjusting lever.

8. Test the operation of the automatic self-adjuster.

- Pull the brake shoe adjusting lever cable and check that the brake shoe adjusting lever rotates the brake shoe adjuster assembly.
- Release the brake shoe adjusting lever cable and check that the brake shoe adjusting lever advances to the next notch on the brake shoe adjusting screw nut.

9. Adjust the brakes. See Adjustments.

10. Install the brake drum. See Service and Repair.