Front Brake Caliper Overhaul (J90, J95, J96)

Front Brake Caliper Overhaul (J90, J95, J96)

Disassembly Procedure

Warning:
Refer to Brake Dust Warning Brake Dust Warning.


Warning:
Refer to Brake Fluid Irritant Warning Brake Fluid Irritant Warning.


Note:
Replace all the components included in the repair kits used to overhaul the brake caliper.

1. Remove the brake caliper. Refer to Front Brake Caliper Replacement (J90, J95, J96) Front Brake Caliper Replacement (J90, J95, J96)Front Brake Caliper Replacement (JD9, JF3, JF7, JG4) Front Brake Caliper Replacement (JD9, JF3, JF7, JG4).

2. Place a wood block between the brake caliper pistons and the brake caliper housing bridge.





Warning

Do not place fingers in front of the caliper piston(s) in an attempt to catch or protect it when applying compressed air. The piston(s) can fly out with force and could result in serious bodily injury.

3. Place a clean shop towel between the brake caliper pistons and the block of wood.

4. Apply compressed air through the brake hose fitting inlet port and remove the brake caliper pistons (1).

5. Remove the brake caliper bleeder screw.





6. Using a blunt wooden or plastic tool, remove the brake caliper piston dust boots (1).





7. Using a blunt wooden or plastic tool, remove the brake caliper piston seals (1).

8. Inspect the brake caliper bores for corrosion, grooves, and scoring.

* Inspect the caliper piston bores

* Inspect the caliper piston seal grooves

If excessive corrosion, grooving, or scoring is found, replace the brake caliper.

9. Clean the brake caliper housing and any parts to be reused with denatured alcohol.

10. Dry all components with dry, filtered, non-lubricated compressed air.

Assembly Procedure

1. Apply a light coating of GM approved brake fluid from a clean, sealed brake fluid container to the brake caliper components:

* Brake caliper piston bores

* Brake caliper pistons

* Brake caliper piston seals





2. Install the brake caliper piston seals (1) to the brake caliper piston bores.

Ensure the brake caliper piston seals are fully seated in the groove of the caliper piston bores and are not distorted.





3. Install the boot over the end of the piston so that the fold will face toward the brake caliper housing piston bore opening.





Note:
Position the piston in the bore so that it is straight and level.

4. Position the piston to the brake caliper housing bore and seat the boot into the brake caliper housing bore.





5. Position a piece of wood across the piston to be installed.

6. Applying equal pressure by hand while pushing down, install the piston in the bore. Do not press on piston recess with any tool.

7. Remove the piece of wood.

8. Seat the edge of the brake caliper dust seals in the groove in the brake caliper piston.

9. If necessary, carefully lift the edge of the brake caliper dust seals at the brake caliper piston to release any trapped air.





10. Install the bleeder valve in the brake caliper housing and tighten to 10 Nm (89 lb in).

11. Install the bleeder valve cap.

12. Install the brake caliper. Refer to Front Brake Caliper Replacement (J90, J95, J96) Front Brake Caliper Replacement (J90, J95, J96)Front Brake Caliper Replacement (JD9, JF3, JF7, JG4) Front Brake Caliper Replacement (JD9, JF3, JF7, JG4).