Brake Shoe: Service and Repair

REMOVAL PROCEDURE

Tools Required
- J38400 Brake Shoe Spanner and Spring Remover

CAUTION: Keep fingers away from rear brake shoe springs to prevent fingers from being pinched between spring and shoe web or spring and backing plate.

NOTICE:
- Do not pry against the splash shield or backing plate in attempt to free the drum. This will bend the splash shield or backing plate. A bent backing plate may cause brake chatter and/or pulsation.
- Do not over stretch the Adjuster spring. Damage can occur if the spring is over stretched.

1. Raise and suitably support the vehicle.
2. Remove the brake drum.





3. Remove the adjuster spring.
3.1. Use the J 38400 in order to pry the loop end of the adjuster spring from the adjuster actuator (1).
3.2. Disengage the adjuster spring from the web of the parking brake shoe.
4. Lift the end of the return spring (2) from the adjuster shoe and the lining (1).
4.1. Insert the hook end of the J 38400 between the return spring (2) and the adjuster shoe web.
4.2. Pry or twist the J 38400 in order to lift the end of the spring (2) out of the shoe web hole.





5. Pry the end of the return spring (2) toward the axle using the flat edge of the J 38400 until the return spring (2) snaps down off the shoe web onto the backing plate.
6. Remove the adjuster actuator from the shoe and lining (1), and the adjuster screw.
7. Remove the parking brake lever from the parking brake shoe and lining. Do not remove the parking brake cable from the parking brake lever unless you are replacing the parking brake lever.
8. Lift the end of the return spring (2) from the parking brake shoe and lining.
8.1. Insert the hook end of the J38400 between the return spring (2) and the parking brake shoe web.
8.2. Pry or twist the J 38400 in order to lift the end of the spring (2) out of the shoe web hole.
9. Pry the end of the return spring toward the axle using the flat edge of the J 38400 until the return spring (2) snaps down off the shoe web onto the backing plate.
10. Remove the shoe and lining (1).





11. Remove the return spring (2) from the backing plate. Do not remove the return spring (2) if only the shoes and linings (1) are being replaced.
12. Clean all the parts in clean denatured alcohol.
13. Inspect all component parts.
14. Replace any parts that are of doubtful strength or quality due to discoloration from heat, overstress, or excessive wear.
15. Inspect the wheel cylinder for leakage and cut or damaged boots. Remove and replace the wheel cylinder as necessary. Do not attempt to repair the wheel cylinder.

INSTALLATION PROCEDURE

IMPORTANT: Lubricate the following parts using GM P/N 1052196 brake lubricant (or equivalent):
- Six raised shoe pads on the backing plate
- Anchor surfaces on the backing plate that contact the lower ends of the brake shoes
1. If the return spring was removed, reinstall the hooking center spring section under the tab on the backing plate.
2. Install the shoe and lining.
2.1. Position the shoe and lining on the backing plate.
2.2. Use the J 38400 in order to pull the end of the return spring up and rest the return spring on the web of the brake shoe.
2.3. Use the J 38400 in order to pull the end of the return spring over until it snaps into the slot in the brake shoe.
3. Install the parking brake lever to the parking brake shoe and lining.
4. Install the parking brake cable to the parking brake lever, if disconnected.
5. Before reinstalling the adjuster screw, disassemble, clean and lubricate the adjuster screw.
5.1. Clean the adjuster screw threads. Use a wire brush.
5.2. Wash all components in clean denatured alcohol.
5.3. Apply GM P/N 1052196 brake lubricant (or equivalent) to the following components:
- The adjuster screw threads
- The inside diameter of the adjuster socket
- The socket face
5.4. Adequate lubrication is achieved when a continuous bead of lubricant is on the end of the adjuster nut and the socket when the threads are fully engaged.
6. Inspect the threads of the adjuster screw for smooth rotation over the full length.
7. Install the adjuster screw (2) and the adjuster shoe and lining (4 and 5).
7.1. Engage the adjuster nut end of the adjuster screw (2) using the web of the parking brake shoe and lining and the parking brake lever (3).
7.2. Position the adjuster shoe and lining so that the shoe web engages the deep slot in the socket end of the adjuster screw (2).





8. install the return spring (2) into the adjuster shoe and lining (1). Use the J 38400 in order to pull the end of the return spring up (2) and rest the return spring on the web of the brake shoe.





9. Use the J 38400 in order to pull the end of the return spring (2) over until it snaps into the slot in the brake shoe.





10. Install the adjuster actuator (1).
10.1. Lubricate the tab and the pivot point on the adjuster lever using GM P/N 1052196 brake lubricant (or equivalent).
10.2. Use the J 38400 in order to spread the brake shoes. Manipulate the adjuster actuator (1) into position.
11. Install the adjuster spring.
11.1. Engage the U-shaped end of the spring into the hole in the web of the parking brake shoe.
11.2. Use the J 38400 in order to stretch the spring and engage the loop end over the tab on the adjuster actuator.
12. Ensure proper positioning and function of the adjuster actuator. Verify the following conditions:
- The adjuster actuator pivot is in the web shoe slot.
- The notch in the adjuster actuator is on the step in the adjuster screw notch.
The arm of the adjuster actuator rests freely on the star wheel teeth of the adjuster screw. The arm of the adjuster actuator SHOULD NOT be trapped under the teeth at a downward angle.
- Install the J 38400 between the upper ends of the shoe and lining assemblies. Spread the shoes apart and watch for proper rotation of the star wheel.
13. Adjust the brakes.
14. Adjust the parking brake.
15. Install the brake drum.
16. Lower the vehicle.