The rear brake shoe linings should show contact across the entire width of the lining, and also from the heel to the toe of the lining. It not, the brake shoes should be replaced. You should always replace the brake shoes in axle sets.
Brake shoes that don't contact at the toe or heel might be improperly grounded.
Clean and inspect the brake support plate and adjusting screws. Apply a thin coat of multi-purpose lubricant to the threads of the self adjuster. If it becomes corroded, you should replace the adjusting screw.
REMOVAL & INSTALLATION
See Figures 1 through 19
- Raise and safely support the vehicle. Remove the wheel and tire assembly.
- If equipped, remove the brake drum-to-hub and bearing assembly retaining clips, then remove the brake drum.
- Remove the adjustment lever-to-leading brake shoe spring.
- Remove the automatic adjustment lever from the brake shoe.
- Remove the hold-down clips and pins attaching the leading and trailing brake shoes to the brake support plate.
- Remove the lower brake shoe-to-anchor plate return spring.
- Remove the parking brake lever pin-to-rear brake shoe retaining clip.
- If possible with the hub and bearing in place, remove the leading and trailing brake shoes, upper return spring, and automatic adjuster screw from the brake support (backing) plate as an assembly.
If its not possible to remove the brake shoes, spring and adjuster screw as an assembly because the hub is in the way, perform the following:
Pull the leading brake shoe away from the backing plate, unhook the return spring, then remove the shoe from the vehicle.
Unhook the return spring from the trailing shoe, disengage the shoe from the parking brake lever, then remove the shoe from the vehicle.
Remove the automatic adjusting screw from the backing plate.
If necessary, grasp the sparking brake cable, then detach the parking brake lever from the cable.
- Pull the leading brake shoe away from the backing plate, unhook the return spring, then remove the shoe from the vehicle.
- Lubricate the eight shoe contact areas on the support plate and anchor using a suitable multi-purpose lubricant.
- Before installation on the brake plate, assemble the front and rear brake shoe assembly, automatic adjuster screw and upper return spring.
- Install the pre-assembled brake shoe assembly on the brake support plate.
- Install the wave washer on the pin of the parking brake lever.
- Install the pin on the parking brake lever into the hole in the rear brake shoe assembly.
- Install both brake shoes to the brake support plate, then install the hold-down pins and clips.
- Install the lower brake shoe-to-anchor plate return spring.
- Install the automatic adjustment lever, on the front brake shoe of the rear brake assembly.
- Install the automatic adjustment lever to the front brake shoe assembly spring.
- Adjust the brake shoe assemblies so they don't interfere with the brake drum installation.
- Install the brake drum on the hub. If equipped, install the retaining clips.
- Adjust the rear brake shoes, as outlined later in this section.
- Install the wheel and tire assembly, then carefully lower the vehicle.
See Figures 20 and 21
Usually, self-adjusting drum brakes do not necessitate manual adjustment. However, in the event of a brake reline, you should make the initial adjustment to speed up the adjustment period.
- Make sure the parking brake is fully released.
- Raise and safely support the vehicle so that all wheels are free to turn.
- Remove the rear brake adjusting hole rubber plug from the rear of the brake shoe support plate.
- Insert a suitable brake adjusting tool through the adjusting hole in the support plate and against the star wheel of the adjusting screw. Move the handle of the tool downward until a slight drag is felt when the tire is rotated.
- Insert a thin screwdriver or equivalent into the adjusting hole. Push the adjusting lever out of engagement with the star wheel. Be very careful not to bend the adjusting lever or contort the lever spring. While holding the adjusting lever out of engagement with the star wheel, back off the star wheel to guarantee a free wheel with no drag.
- Repeat the adjustment procedure at the other rear wheel. After the procedure is complete, install the adjusting hole rubber plugs in the rear brake support plates.
- After adjustment, apply and release the parking brake lever one time.
- Carefully lower the vehicle.