Once the drum is removed from the rear hub, clean the shoes and springs with a damp rag to remove the accumulated brake dust.
Grease on the shoes can be removed with alcohol or fine sandpaper. After cleaning, examine the brake shoes for glazed, oily, loose, cracked or improperly (unevenly) worn linings. Light glazing is common and can be removed with fine sandpaper. Linings that are worn improperly or below specification (refer to the specification chart). A good "eyeball'' test is to replace the linings when the thickness is the same as or less than the thickness of the metal backing plate (shoe).
Wheel cylinders are a vital part of the brake system and should be inspected carefully. Gently pull back the rubber boots; if any fluid is visible, it's time to replace the wheel cylinders. Boots that are distorted, cracked or otherwise damaged, also point to the need for service. Check the flexible brake lines for cracks, chafing or wear.
Check the brake shoe retracting and hold-down springs; they should not be worn or distorted. Be sure that the adjuster mechanism moves freely. The points on the backing plate where the shoes slide should be shiny and free of rust. Rust in these areas suggests that the brake shoes are not moving properly.
REMOVAL & INSTALLATION
See Figures 1 through 12
- Loosen the lug nuts on the rear wheels.
- Raise the vehicle and support safely. Remove the rear wheels and brake drums.
- Remove the dust cap from the rear hub and bearing assembly. Then remove the cotter pin and the nut lock from the spindle.
- Remove the rear hub and bearing assembly retainer nut and washer. Remove the rear hub and bearing assembly from the spindle.
- Remove the automatic adjuster spring from the adjuster lever.
- Rotate the automatic adjuster star wheel enough so both shoes move out far enough to be free of the wheel cylinder boots.
- Disconnect the parking brake cable from the actuating lever. Disconnect parking brake cable one side at a time.
- Remove the both lower brake shoe-to-anchor springs.
- Remove the 2 brake shoe hold-down springs from the brake shoes.
- Remove the brake shoes, upper shoe-to-shoe return spring, automatic adjuster and automatic adjuster lever from the backing plate as an assembly.
- Separate the brake shoes from the automatic adjuster mechanism.
- Remove the brake shoe automatic adjuster lever from the leading brake shoe.
- Thoroughly clean and dry the backing plate. To prepare the backing plate, lubricate the bosses, anchor pin and parking brake actuating lever pivot surface lightly with lithium based grease.
- Remove, clean and dry all parts still on the old shoes. Lubricate the star wheel shaft threads with anti-seize lubricant.
- Assemble both brake shoes, the top shoe-to-shoe return spring, automatic adjuster and automatic adjuster lever before mounting on vehicle. Make sure the ends of the automatic adjusters are positioned above the extruded pins in the webbing of the brake shoes prior to installation.
- Install the brake shoe assembly onto the brake support plate and install the hold-down springs.
- Install the lower anchor springs and reconnect the parking brake cable to the park brake lever of the trailing brake shoe.
- Rotate the serrated adjuster nut to remove the free-play from the adjuster assembly. Install the automatic adjuster lever spring on the lead brake shoe assembly and the automatic adjuster lever.
- Install the rear hub and bearing assembly. Install the washers and retainer nuts and tighten to 124 ft. lbs. (168 Nm).
- Install the nut lock, new cotter pin and dust cover to the rear spindle.
- Adjust brake shoes so not to interfere with brake drum installation. Install the rear brake drums.
After installing the brake drums, pump the brake pedal several times to partially adjust the brake shoes. To verify proper operation of the self-adjusting parking brake, be sure that both rear brakes are not dragging when the parking brake pedal is released.
- Install the rear wheels and hand-tighten the lug nuts.
- Lower the vehicle and tighten the lug nuts, in a star pattern sequence, to 95 ft. lbs. (129 Nm).
- Road test the vehicle. The automatic adjusters will continue brake adjustment during the road test of the vehicle.