- Inspect the rear brake shoes and linings for excessive lining wear or shoe damage. If the lining is damaged or worn within 1 / 32 in. (0.79mm), it must be replaced. Replace any lining that has been contaminated with oil, grease or brake fluid. Replace the linings in axle sets only. Never replace just one rear shoe and lining of a brake assembly. Replace both leading and trailing shoes.
Replace the brake shoe and lining in axle sets only. Never replace just one shoe of a brake assembly.
- Before replacing the lining, check the brake drum diameter to determine if the brake drum diameter is within specifications. If the braking surface diameter exceeds specifications, the drum must be replaced.
- Check the condition of the brake shoes and linings, retracting spring, hold-down springs and brake drum for signs of overheating. If the brake shoes and linings have a slight blue coloring, this indicates overheating and retracting. Replace the hold-down springs. If not replaced, overheated springs could lose their tension and allow the new lining to drag and wear prematurely.
REMOVAL & INSTALLATION
If you are not thoroughly familiar with the procedures involved in brake replacement, only disassemble and assemble one side at a time, leaving the other wheel intact as a reference.1983-88 Vehicles
See Figures 1, 2 and 3
- Raise and safely support the rear of the vehicle with jackstands.
- Remove the tire and wheel assembly.
- Remove the brake drum, as outlined earlier in this section.
- Place Brake Cylinder Clamp D81L-1103-B or equivalent, over the ends of the brake cylinder.
- Remove the shoe-to-anchor springs, using Brake Shoe R and R Spring BT-11, or equivalent, then unhook the cable eye from the anchor pin.
- Remove the shoe guide (anchor pin) plate.
- Remove the shoe hold-down springs, shoes, adjusting screws, pivot nut, socket and automatic adjustment parts.
- Remove the parking brake link, spring and retainer. Disconnect the parking brake cable from the parking brake lever.
- After removing the secondary brake shoe, disassembly the parking brake lever from the shoe by removing the retaining clip and spring washer.
- The brake cable must be connected to the secondary brake shoe before the shoe is installed on the backing plate. To do this, first transfer the parking brake lever from the old secondary shoe to the new one. This is accomplished by spreading the bottom of the horseshoe clip and disengaging the lever. Position the lever on the new secondary shoe and install the spring washer and the horseshoe clip. Close the bottom of the clip after installing it. Grasp the metal tip of the parking brake cable with a pair of pliers. Position a pair of side cutter pliers on the end of the cable coil spring, and using the plier as a fulcrum, pull the coil spring back with the side cutters. Position the cable in the parking brake lever.
- Apply a light coating of high temperature grease to the brake shoe contact points on the backing plate. Position the primary brake shoe on the front of the backing plate and install the hold-down spring and washer over the mounting pin. Install the secondary shoe on the rear of the backing plate.
- Install the parking brake link between the notch in the primary brake shoe and the notch in the parking brake lever.
- Install the automatic adjuster cable loop end on the anchor pin. Make sure the crimped side of the loop faces the backing plate.
- Install the return spring in the primary brake shoe and, using the tapered end of the brake spring service tool, slide the top of the spring onto the anchor pin.
- Install the automatic adjuster cable guide in the secondary brake shoe, making sure the flared hole in the cable guide is inside the hole in the brake shoe. Fit the cable into the groove in the top of the cable guide.
- Install the secondary shoe return spring through the hole in the cable guide and the brake shoe. Using the brake spring tool, slide the top of the spring onto the anchor pin.
- Clean the threads on the adjusting screw and apply a light coating of high temperature grease to the threads. Screw the adjuster closed, then open it 1 / 2 turn.
- Install the adjusting screw between the brake shoes with the star wheel nearest to the secondary shoe. Make sure the star wheel is in a position that is accessible from the adjusting slot in the backing plate.
- Install the short hooked end of the automatic adjuster spring in the proper hole in the primary brake shoe.
- Connect the hooked end of the automatic adjuster cable and the free end of the automatic adjuster spring in the slot in the top of the automatic adjuster lever.
- Pull the automatic adjuster lever (the lever will pull the cable and spring with it) downward and to the left and engage the pivot hook of the lever in the hole in the secondary brake shoe.
- Check the entire brake assembly to make sure that everything is installed properly. Make sure that the shoes engage the wheel cylinder properly and are flush on the anchor pin. Make sure that the automatic adjuster cable is flush on the anchor pin and in the slot on the back of the cable guide. Make sure that the adjusting lever rests on the adjusting screw star wheel. Pull upward on the adjusting cable until the adjusting lever is free of the star wheel, then release the cable. The adjusting lever should snap back into place on the adjusting screw star wheel and turn the wheel one tooth.
- Expand the brake adjusting screw until the brake drum will just fit over the brake shoes.
- Install the brake drum and wheel and tire assembly, then adjust the brakes.
- Carefully lower the vehicle.
See Figures 4, 5, 6, 7, 8, 9 and 10
- Raise and safely support the vehicle.
- Remove the rear wheel and tire assemblies, then remove the brake drum.
- Install Brake Cylinder Clamp D81L-1103-B or equivalent, over the ends of the rear wheel cylinder.
- Disconnect the parking brake cable from the parking brake lever.
- Remove the 2 brake shoe hold-down retainers, springs and pins.
- Spread the brake shoes over the piston shoe guide slots. Lift the brake shoes, springs and adjuster off the backing plate as an assembly. Be careful not to bend the adjusting lever.
- Remove the adjuster spring. To separate the shoes, remove the retracting springs.
- Remove the parking brake lever retaining clip and spring washer. Remove the lever from the pin.
- Apply a light coating of caliper slide grease to the backing plate brake shoe contact areas.
- Apply a light coat of lubricant to the threaded areas of the adjuster screw and socket. Assemble the brake adjuster with the stainless steel washer. Turn the socket all the way down on the screw, then back off 1 / 2 turn.
- Install the parking brake lever to the trailing shoe with the spring washer and a new retaining clip. Crimp the clip to securely retain the lever.
- Position the trailing shoe on the backing plate and attach the parking brake cable. Position the leading shoe on the backing plate and attach the lower retracting spring to the brake shoes.
- Install the adjuster assembly to the slots in the brake shoes. The socket end must fit into the wider slot in the leading shoe. The slot in the adjuster nut must fit into the slots in the trailing shoe and parking brake lever.
- Install the adjuster lever on the pin on the leading shoe and to the slot in the adjuster socket.
- Install the upper retracting spring in the slot on the trailing shoe and the slot in the adjuster lever. The adjuster lever should contact the star and adjuster assembly.
- Install the brake shoe anchor pins, springs and retainers. Remove the brake cylinder clamp tool
- Install the brake drum, wheel and tire assemblies and lower the vehicle.
- Apply the brakes several times while backing up the vehicle. After each stop, the vehicle must be moved forward.