Removal Procedure
Tools Required
J 38400 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.
Notice: Do not over stretch the adjuster spring. Damage can occur
if the spring is over stretched.
- Raise and suitably support the vehicle. Refer to
Lifting and Jacking the Vehicle
in General Information.
- Mark the relationship of the wheel to the axle flange.
- Remove the tire and the wheel. Refer to
Tire and Wheel Removal and Installation
in Tires
and Wheels.
- Mark the relationship of the drum to the axle flange.
- Remove the brake drum.
If difficulty is encountered in removing the brake drum, the following steps
may be of assistance:
5.1. | Remove the retainer clip |
5.2. | Verify that the parking brake is released |
5.3. | Back off the parking brake cable adjustment |
5.4. | Remove the access hole plug from the backing plate (1) |
5.5. | Use a flat bladed tool (2) in order to back off the adjusting
screw |
5.6. | Reinstall the access hole plug in order to prevent dirt or contamination
from entering the drum brake |
5.7. | Apply a small amount of penetrating oil around the drum pilot
hole |
- Remove the adjuster spring
(1). Use the J 38400
in order to pry the loop end of the adjuster spring from the adjuster
actuator. Then disengage the adjuster spring from the web of the parking
brake shoe.
- Remove the lift end of
the return spring (2) from the adjuster shoe and the lining (1).
- Insert the hook end of the J 38400
between the return spring and the adjuster shoe web.
- Pry or twist the J 38400
in order to lift the
end of the spring (2) out of the shoe web hole.
- Pry the end of the return
spring (2) toward the axle with the flat edge of the J 38400
until the return spring snaps down
off the shoe web onto the backing plate.
- Remove the adjuster actuator
(1) from the following components:
• | The brake lining (4, 5) |
• | The adjusting screw (2) |
- Remove the parking brake lever (3) from the parking brake shoe
and the parking brake lining. Do not remove the parking brake cable from
the parking brake lever unless the parking brake lever is to be replaced.
- Lift the end of the return
spring (2) from the parking brake shoe and the parking brake lining (1).
Insert the hook end of the J 38400
between the return spring and the parking brake shoe web.
Pry or twist the J 38400
in order to lift the end of the spring out of the shoe web hole.
- Pry the end of the return
spring (2) toward the axle with the flat edge of the J 38400
until it snaps down off the shoe web
onto the backing plate.
- Remove the parking brake shoe and the parking brake lining.
- Remove the return spring from the backing plate. If only the shoes
and linings are being replaced, do not remove the return spring.
- Clean all parts in clean denatured alcohol.
- Inspect and replace any parts that are of doubtful strength or
quality due to the following conditions:
• | Discoloration from heat |
- Inspect the wheel cylinder for the following conditions:
- Do not attempt to repair the wheel cylinder. Replace the wheel
cylinder, refer to
Wheel Cylinder Replacement
.
Installation Procedure
Important: Lubricate the following components with GM P/N 1052196 or equivalent
brake lubricant:
• | The six raised shoe pads on the backing plate |
• | The anchor surfaces on the backing plate. The anchor surfaces
contact the lower ends of the brake shoes. |
- Reinstall the hooking center spring section under the tab on the anchor,
if the return spring was removed.
- Install the parking brake shoe and lining. Position the shoe and
the lining on the backing plate.
- Use the J 38400
in order to pull up the end of the return spring (2), resting
the return spring on the web of the brake shoe (1).
- Use the J 38400
in order to pull the end of the return spring over until the return
spring snaps in the slot in the brake shoe.
- Connect the parking brake
lever (3) to the parking brake shoe and lining (4).
- Connect the parking brake cable to the parking brake lever, if
disconnected.
- Before reinstallation, disassemble, thoroughly clean and lubricate
the adjusting screw (2) in the following manner:
• | Clean the adjuster screw threads with a wire brush. |
• | Wash all components in clean denatured alcohol. |
• | Apply GM P/N 1052196 or equivalent brake lubricant to the following
areas: |
• | The adjuster screw threads |
• | The inside the diameter of the adjuster socket |
• | 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 |
- Inspect the threads of the adjuster screw for smooth rotation
over the full length.
- Install the following
components:
• | The adjusting screw (2) |
• | The adjuster shoe lining |
• | Engage the adjuster nut end of the adjusting screw (2) with the
web of the parking brake shoe and lining and the parking brake lever (3) |
• | Position the adjuster shoe and lining so that the shoe web engages
the deep slot in the socket end of the adjusting screw |
- Install the return spring into the adjuster shoe and lining.
10.1. | Use the J 38400
in order to pull up the end of the return spring, resting the return
spring on the web of the brake shoe. |
10.2. | Use the J 38400
in order to pull the end of the return spring over until the return
spring snaps in the slot in the brake shoe. |
- Install the adjuster actuator.
11.1. | Lubricate the tab and the pivot point on the adjuster lever with
GM P/N 1052196 or equivalent brake lubricant. |
11.2. | Use the J 38400
in order to spread the brake shoes while working the adjuster actuator
(1) into position. |
- Install the adjuster spring.
12.1. | Engage the U-shaped end of the spring in the hole in the web
of the parking brake shoe. |
12.2. | Use the J 38400
in order to stretch the spring and engage the loop end over the
tab on the adjuster actuator. |
- Note the following items
in order to ensure the proper positioning and function of the adjuster actuator:
• | The adjuster actuator (8) pivots in the shoe web slot |
• | The notch in the adjuster actuator rests on the step in the adjusting
screw (2) notch |
• | The arm of the adjuster actuator rests freely on the star wheel
teeth of the adjuster screw, not trapped under the teeth in a downward angle |
• | Use 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 |
- Adjust the brakes. Refer to
Drum Brake Adjustment
.
- Adjust the parking brake.
For the drum brakes, refer to
Park Brake Cable Service/Adjustment
in Park Brake.
- Install the brake drums. Align the marks made during removal.
- Install the tires and the wheels. Align the marks made during
removal. Refer to
Tire and Wheel Removal and Installation
in Tires and Wheels.
- Lower the vehicle.