See Figure 1
See Figures 2, 3 and 4
When servicing drum brakes, only dissemble and assemble one side at a time, leaving the remaining side intact for reference.
A hole is located in the back of the back plate under and inspection plug, check the shoe lining thickness through the hole.
- Inspect all parts for rust and damage.
- Measure the lining thickness. The minimum allowable thickness is 0.039 inch (1.0mm). If the lining does not meet the minimum specification, replace it.
If one of the brake shoes needs to be replaced, replace all the rear shoes in order to maintain even braking.
- Measure inside diameter of the drum as detailed in this Section.
- Place the shoe into the drum and check that the lining is in proper contact with the drum's surface. If the contact is improper, repair the lining with a brake shoe grinder or replace the shoe.
- To measure the clearance between brake shoe and parking brake lever, temporarily install the parking brake and automatic adjusting levers onto the rear shoe, using a new C-washer/shim. Replace the shim with the correct size, check the chart. With a feeler gauge, measure the clearance between the shoe and the lever. The clearance should be 0.0138 inch (0.35mm). If the clearance is not as specified, use a shim to adjust it. When the clearance is correct, stake the C-washer with pliers.
REMOVAL & INSTALLATION
See Figures 5 through 15
When servicing drum brakes, only dissemble and assemble one side at a time, leaving the remaining side intact for reference. The hub can be removed to access the brake components much easier, but is not necessary. The hub has been removed for photographic reasons.
- Loosen the rear wheel lug nuts slightly. Release the parking brake.
- Block the front wheels, raise the rear of the vehicle, and safely support it with jackstands.
- Remove the wheel lug nuts and the wheel.
- Remove the brake drum.
Do not depress the brake pedal once the brake drum has been removed.
- Carefully unhook the return spring from the leading (front) brake shoe.
- Press the hold-down spring retainer in and turn the pin on the front brake shoe.
- Remove the hold-down spring, retainers and the pin for the front brake shoe.
- Pull out the brake shoe and unhook the anchor spring from the lower edge.
- Remove the hold-down spring, cups and pin from the trailing (rear) shoe. Pull the shoe out with the adjuster, automatic adjuster assembly and springs attached. Disconnect the parking brake cable. Remove the tension/return and anchor springs from the rear shoe.
- Remove the c-washer, automatic adjusting lever, other c-washer, then extract the adjusting lever and parking brake lever from he rear shoe.
- Inspect the shoes for signs of unusual wear or scoring.
- Check the wheel cylinder for any sign of fluid seepage or frozen pistons.
- Clean and inspect the brake backing plate and all other components. Check that the brake drum inner diameter is within specified limits. Lubricate the backing plate at the positions the brakes come in contact with the backing plate. Also lubricate the anchor plate.
- Mount the automatic adjuster assembly onto a new rear brake shoe.
- Using pliers, connect the parking brake cable to the lever, then set the adjuster and return spring. Install the adjusting lever spring. Position the rear shoe so the lower end rides in the anchor plate and the upper end is against the boot of the wheel cylinder.
- Install the pin and the hold-down spring. Press the retainer down over the pin and rotate the pin so the crimped edge is held by the retainer.
Do not allow oil or grease to get on the rubbing face.
- Place the front brake into position and install the anchor spring between the front and rear shoes. Stretch the spring enough so the front shoe will fit as the rear did. Install the hold-down spring, pin and retainer to the front brake shoe.
- Connect the return spring to the front brake shoe.
- Check the operation of the automatic adjuster mechanism:
Check the clearance between the brake shoes and drum:
- Remove the brake drum.
Measure the brake drum inside diameter and diameter of the brake shoes. The difference is "Shoe-to-drum clearance" and should be approximately 0.024 inch (0.6mm). If incorrect, check the parking brake system.A special brake caliper tool is required to gauge the brake drum inside diameter and "Shoe-to-drum clearance". However it is not required to perform brake shoe adjustment.