The rear brakes do not require manual adjustment. Adjust the shoes by sharply applying the brake pedal several times while driving the vehicle alternately forwards and backwards. Check the brake operation by making several stops while driving forward. The self-adjusting mechanism will sufficiently adjust the rear brake shoes without any manual tightening at the brake shoe adjuster. If the rear brake shoes are manually adjusted, the additional action of the brake shoe adjuster can cause the brakes to become over-tightened and result in binding or overheated rear brakes.
Inspect the brake shoes for wear using a ruler or Vernier caliper. The brake lining thickness should be 0.059 - 0.232 inch (1.5 - 5.9mm). If the lining is thinner than specification or there is evidence of the lining being contaminated by brake fluid, repair the leak and replace all brake shoe assemblies (a complete axle set). In addition to the shoes inspect all springs and brake shoe hardware for wear and replace as necessary.
Removal & Installation
- Before servicing the vehicle, refer to the Precautions section.
The rear drum brakes use an internal rear wheel cylinder with expanding shoes and lining that are applied against a rotating brake drum. An incremental brake adjuster screw is actuated whenever sufficient wear occurs. Brake adjustment takes place in forward or reverse braking but not with parking brake application.
Remove or disconnect the following:
- Clean all parts well.
- Inspect the wheel cylinder for signs of leaking. Service as required.
- Inspect the retracting springs for heat damage, bends or damage to the coils or shank or loss of tension. A good retracting spring will make a full thud when dropped on a concrete floor. A heat-damaged retracting spring that has lost tension will make a distinctive ringing sound when dropped on a concrete floor.
- Check the brake backing plate for signs of scoring. The shoe contact points must be smooth and have a light coating of lithium grease. Verify that the brake lining thickness is between 0.059-0.232 in. (1.5-5.9mm). Failure to replace worn rear brake shoes will result in a scored drum.
Inspect the brake drum for scratches, scoring, bell mouth and out-of-round conditions. Remove minor scores on a brake drum with sandpaper. Do not refinish brake drums to remove scoring marks. A brake drum surface that is highly polished can cause the brakes to lock up. Remove polished surfaces with sandpaper or refinish the brake drum. Refinish a brake drum that is out-of-round enough to cause vehicle vibration or noise when braking. Remove only enough surface metal to true-up the brake drum. Brake drum maximum inside diameter is shown on each drum. If the maximum inside diameter shown on the brake drum is exceeded through wear or refinishing, replace the brake drum. After a brake drum is refinished, wipe the refinished surface with a cloth soaked in clean denatured alcohol. If one brake drum is refinished, the brake drum on the opposite side of the vehicle should also be refinished to the same diameter. The standard inner brake drum diameter is 9.840 inches (250.0mm). Replace the brake drum if worn beyond 9.900 inches (251.5mm).
Install or connect the following:
Parking brake lever to the secondary brake shoe and lining with a new parking brake lever clip
- Apply a light coat of high-quality grease to the threaded areas of the adjuster nut and adjuster socket. Turn the adjuster nut all the way down on the brake adjuster screw, then loosen the adjuster 1 / 2 turn. Install the adjuster screw in the slots on the rear brake shoes. The wider slot on the socket must fit in the slot on the primary (front) brake shoe. The slot on the adjuster nut end must fit into the slots in the secondary (rear) brake shoe and parking brake lever.
Install or connect the following:
NOTEIn most all cases, manual brake adjustment IS NOT recommended. Adjustment is performed by driving the vehicle and applying the brakes.
Brake shoe adjusting lever on the adjuster lever pin
- The rear brakes do not require adjustment when being serviced to obtain a firm brake pedal feel. To achieve a firm brake pedal after servicing the rear brakes, sharply apply the brake pedal several times while driving the vehicle alternately forwards and backwards. Check the brake operation by making several stops while driving forward. If the rear brake shoes are manually adjusted, the additional action of the brake shoe adjuster can cause the brakes to become over-tightened and result in binding or overheated rear brakes.
- Loosen the lug nuts on the rear wheels.
- Block the front wheels, then raise and safely support the rear of the vehicle securely on jackstands.
- Remove the rear wheels.
- Remove the brake drum.
- Using a pair of side cutters, pull the parking brake cable return spring back on the cable. Disconnect the parking brake rear cable from the parking brake lever.
- Remove the two brake shoe hold-down springs and hold-down pins.
- Using a pair of needlenose pliers, remove the upper retracting spring and brake adjusting lever.
- Using a pair of needlenose pliers, remove the lower retracting spring.
- Remove the brake adjuster screw.
- Remove the rear brake shoes and linings from the backing plate.
Remove the parking brake lever clip and washer from the secondary brake shoe and remove the lever from the shoe.
- Clean the backing plate, springs, hold-down assemblies, and adjusters using a commercially available brake cleaning fluid.
- Apply a light coating of silicone dielectric compound, such as Ford D7AZ-19A331-A or equivalent silicone grease, at the points where the brake shoes contact the backing plate.
- Apply a thin coat of lubricant to the adjuster screw threads and socket end of the adjusting screw. Install the stainless steel washer over the socket end of the adjusting screw and install the socket. Turn the adjusting screw into the adjusting pivot nut to the limit of the threads and then back off 1 / 2 turn.
- Assemble the parking brake lever to the secondary (rear) shoe by installing the spring washer and a new horse shoe retaining clip. Crimp the clip until it retains the lever to the shoe securely.
- Position the secondary (rear) shoe on the backing plate and install the brake shoe hold-down spring and pin.
- Position the primary (front) shoe on the backing plate and install the brake shoe hold-down spring and pin.
- Attach the parking brake cable to the parking brake lever.
- Attach the lower retracting spring to the rear brake shoes.
- Install the adjuster in the slots on the rear brake shoes. The wider slot on the socket must fit in the slot on the primary brake shoe. The slot on the adjuster nut end must fit into the slots in the secondary brake shoe and parking brake lever.
- Install the brake adjusting lever on the pin of the primary brake shoe.
- Install the upper retracting spring in the slot on the secondary shoe and in the slot on the adjusting lever. The brake shoe adjusting lever should contact the brake adjuster.
- Install the brake drum.
- Install the wheel and tighten the lug nuts to 72 - 87 ft. lbs. (98 - 118 Nm).
- Lower the vehicle.
- Adjust the rear brake shoes by sharply applying the brakes several times while driving the vehicle alternately forwards and backwards. Check the brake operation by making several stops while driving forward.