After removing the brake drum, inspect the brake shoes. If the lining is worn down so that the thickness is less than 0.0394 in. (1mm), the brake shoes must be replaced.
This figure may disagree with your state inspection laws.
If the brake lining is soaked with brake fluid, it must be replaced. Also the brake drum should be sanded with crocus cloth to remove all traces of brake fluid and the wheel cylinders rebuilt. Clean all grit off the brake drum before installing it.
If the brake lining is chipped, cracked, or otherwise damaged, it must be replace with new lining.
Always replace the brake linings (shoes) in sets of two on both ends of the axle. Never replace just one shoe or both shoes on just one side.
Check the condition of the shoes, retracting springs and holddown springs for signs of overheating. If the shoes or springs have a slight blue color, this indicates overheating and replacement of the springs and shoes is recommended. The wheel cylinders should be rebuilt as a precaution against future problems.
REMOVAL & INSTALLATION
See Figures 1 and 2
- Raise and support the vehicle until the wheel which is to be serviced is off the ground. Remove the wheel and brake drum.
- Remove the hub dust cap.
- Straighten the cotter pin and remove it from the spindle.
- Unscrew the spindle nut and remove the adjusting cap, spindle nut, and spindle washer.
- Wiggle the hub assembly until the outer bearing comes unseated and can be removed from the hub. Remove the outer bearing.
- Pull the hub assembly off the spindle.
- Unhook the upper, lower, and after shoe return springs, and remove them from the brake assembly.
- Remove the brake shoes from the wheel cylinder at the top and the adjuster assembly at the bottom.
- Clean the brake backing plate and adjuster assembly so they are free of all dust and dirt. To remove the adjuster assembly for cleaning, remove the rubber boot at the back of the adjuster assembly and slide the adjuster shim, lockplate and retaining spring off the rear of the adjuster assembly.
- Check the wheel cylinders by carefully pulling the lower edges of the wheel cylinder boots away from the cylinders. If there is leakage, the inside of the cylinder will be wet with fluid. If leakage exists, a wheel cylinder overhaul is in order. Do not delay, because brake failure could result.
A trace of fluid will be present, which acts as a lubricant for the wheel cylinder pistons.
- Apply brake grease to the adjuster assembly housing bore, adjuster wheel, and adjuster screw. Assemble the adjuster assembly with the adjuster screw turned all the way in. Apply brake grease to the sliding surfaces of the adjuster assembly, brake backing plate, and the retaining spring. Install the adjuster assembly to the backing plate in the reverse order of removal.
- Before installing the brake shoes, apply brake grease to the notches into which the brake shoes fit on the wheel cylinder and adjuster mechanism, and brake shoe-to-backing plate contact surfaces.
- Install the brake shoes.
- Install the hub, brake drum, and wheel in the reverse order of removal and adjust the wheel bearings and the brake shoes. Bleed the brakes. Lower the vehicle and road test it.