Drum Brake System: Service and Repair
BRAKE DRUM, REAR REMOVAL / INSTALLATION
1. Remove spring nut and the brake drum.
2. Remove in order shown in the figure.
3. Inspect all parts and repair or replace as necessary.
4. Install in reverse order of removal.
5. After installation, check the following:
1. Add fluid and bleed the air.
2. Check for fluid leaks.
3. Depress pedal a few times, then verify that the brakes do not drag while rotating the wheel by hand.
Rear Brake Drum Removal Note
Caution:
^ Use of a drum puller or a torch is not recommended. Drum distortion can result.
Note:
^ If the drum is rusted to the axle shaft pilot diameter, tap the center of the brake drum between the lug bolts.
1. Remove the brake drum.
1. Remove and discard the spring nut.
2. Pull the brake drum off the axle shaft.
Note:
^ If drums will not come off, follow these steps.
2. Loosen the brake shoe adjusting screw nut.
1. Using a screwdriver, move the brake shoe adjusting lever off the brake adjuster screw.
Note:
^ Move the adjustment tool handle downward to loosen the brake shoe adjusting screw nut.
2. Loosen the brake shoe adjusting screw nut.
Parking Brake Strut Removal Note
Note:
^ The parking brake link spring and the brake parking spring retainer will come off with the parking brake strut.
1. Remove the brake shoe anchor pin guide plate, parking brake strut and the parking brake lever pin retainer.
Backing Plate Removal Note
1. Remove the axle shaft or the axle shaft and rear hub.
2. Compress the cable retainer and pull the parking brake rear cable and conduit from the brake backing plate.
3. Remove the wheel cylinder.
4. Remove the four backing plate-to-axle flange nuts and bolts and the brake backing plate.
Brake Shoes and Linings Installation Note
1. Compress the parking brake cable spring and attach the parking brake lever.
2. Clean and lubricate the brake backing plate.
3. Attach the parking brake lever to the rear brake shoe and lining and secure the parking brake lever pin retainer.
4. Position brake shoes and linings (1).
5. Install the brake shoe hold-down spring pins and the brake shoe hold-down springs (2).
Parking Brake Installation Note
1. Install the parking brake link spring and the parking brake spring retainer on the parking brake strut.
2. Install the parking brake strut.
3. Install the brake shoe anchor pin guide plate.
Primary Shoe-Return Spring Installation Note
1. Place adjusting cable over the anchor pin, with crimped side in.
2. Install the short brake shoe retracting spring.
Secondary Shoe-Return Spring Installation Note
Note:
^ Make sure the brake shoe adjusting lever cable is positioned in the cable guide groove.
1. Install the long brake shoe retracting spring.
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.
Adjuster Screw Installation Note
Note:
^ To prevent incorrect installation, the socket end of each brake adjuster screw is stamped R or L.
1. Assemble the brake adjuster screw assembly.
1. Apply grease or an equivalent silicone compound.
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.
2. Install the brake adjuster screw assembly.
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.
3. Test the operation of the automatic self-adjuster.
1. Pull the brake shoe adjusting lever cable and check that the brake shoe adjusting lever rotates the brake shoe adjuster assembly.
2. 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.
4. Adjust the brakes.
5. Install the brake drum.