See Figure 1
Remove the drum and inspect the lining thickness on both brake shoes. A front brake lining should be replaced if it is less than 1 / 8 in. thick at the lowest point on the brake shoe. The limit for rear brake linings is 1 / 16 in. However, these lining thickness measurements may differ from your state inspection laws.
Brake shoes should always be replaced in axle sets.
REMOVAL & INSTALLATION
See Figures 2 through 17
It may be helpful to disassemble and assemble one wheel at a time so that you will have an example to refer to while you are installing the shoes.
- Raise and safely support your vehicle with jackstands.
- For rear brakes, remove the check nuts from the end of the parking brake equalizer bracket and remove all tension on the brake cable.
- Remove the brake drums, as outlined earlier.
The brake pedal must not be depressed while the drums are removed.
- Using a brake tool, remove the shoe springs from their holder.
- Remove the self-adjuster actuator spring.
- Remove the spring from the secondary shoe by pulling it from the anchor pin.
- Remove the hold-down pins. They can be removed with a pair of pliers. Reach around the rear of the backing plate and hold the back of the pin. Turn the top of the pin retainer with the pliers. This will align the elongated tang with the slot in the retainer. Be careful, as the pin is spring-loaded and may fly off when released. Use the same procedure for the other pin assembly.
- Remove the adjuster actuating lever assembly by removing the hold-down pin which is attached to the secondary brake shoe.
Since the actuator, pivot, and override spring are considered an assembly it is not recommended that they be disassembled.
- Remove the shoes from the backing plate. Make sure that you have a secure grip on the assembly as the bottom spring will still exert pressure on the shoes. Slowly let the tops of the shoes come together and the tension will decrease and the adjuster and spring may be removed.
If the linings are to be reused, mark them for identification.
- Remove the parking brake lever from the secondary shoe (rear brakes). Using a pair of pliers, pull back on the spring which surrounds the cable. At the same time, remove the cable from the notch in the shoe bracket. Make sure that the spring does not snap back or injury may result.
- Use a cloth to remove dirt from the brake drum. Check the drums for scoring and cracks. Have the drums checked for out-of-round and service the drums as necessary.
- Check the wheel cylinders by carefully pulling the lower edges of the wheel cylinder boots away from the cylinders. Excessive leakage requires rebuilding or replacement of the wheel cylinder.
A small amount of fluid will be present to act as a lubricant for the wheel cylinder pistons.To install:
- Install the parking brake lever to the secondary shoe with the washer and retaining ring.
- Install the adjusting screw assembly and spring.
The coils of the spring must not be over the star wheel. Left and right hand springs are different do not interchange.
- Spread the shoe and lining assemblies to clear the axle flange, and connect the parking brake cable and install the parts on the truck.
- Install the parking brake strut and spring by spreading the shoes apart. The strut end without the spring engages the parking brake lever. The end with the spring engages the opposite shoe.
- Install the shoe guide.
- Install the actuator lever and return spring.
- Install the hold down pins, lever pivot and hold down springs.
- Install the actuating link on the anchor pin.
- Lift up on the actuator lever and hook the link into the lever.
- Install the shoe return springs, using brake spring pliers.
- Adjust the brakes if necessary.