Front Brake Caliper Overhaul Without J55

Tools Required

J 35777 Caliper Piston Seal Installer

1. Remove the brake caliper (5) from vehicle. Refer to Front Brake Caliper Replacement .

Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

2. Remove the piston by directing low pressure compressed air into the brake caliper inlet hole.




Important: Care must be used when removing the piston boot and seal from the caliper. Use a small plastic or wood tool for removal. Do not use a metal tool because it may damage the caliper bore or seal groove.

3. Remove the brake caliper piston boot (2) from the brake caliper (1).
4. Remove the caliper piston seal (4) from the brake caliper (1).
5. Remove the caliper bleeder screw (5) and cap (6) from the brake caliper.
6. Clean all of the parts. Use clean, denatured alcohol.
7. Dry all of the parts with non-lubricated, low pressure compressed air.
8. Blow out all of the passages in the brake caliper body and the brake caliper bleeder screw.
9. Inspect all of the parts as follows.

•	Piston - Inspect for scoring, nicks, cracks, wear, or corrosion. Replace the piston if any damage is found.

•	Caliper Bore - Inspect for scoring, nicks, cracks, wear, or corrosion. Use crocus cloth to polish out light corrosion. Otherwise, replace the caliper. Do not hone the caliper bore.

•	Seal groove in the caliper bore for nicks or burrs. If found, replace the caliper.

10. Install the new piston seal. Lubricate the seal with clean brake fluid before installing.



11. Install the new piston dust boot seal over the piston.
12. Using the J 35777 fully seat the boot in the caliper.
13. Install the bleeder screw cap and bleeder screw into the caliper.
14. Install the caliper onto the vehicle. Refer to Front Brake Caliper Replacement .

Front Brake Caliper Overhaul J55

1. Replace all the components included in the repair kits used to service this brake caliper.
2. Lubricate the rubber parts with new Delco Supreme 11® (GM P/N 12377967) or equivalent DOT-3 brake fluid to make assembly easier.
3. If any hydraulic component is removed or disconnected, it may be necessary to bleed all or part of the brake system.
4. The torque values specified are for dry, non-lubricated fasteners.
5. Perform the service operations on a clean bench, free from all mineral oil materials.



6. Remove the brake caliper from vehicle. Refer to Front Brake Caliper Replacement .
7. Drain the brake fluid from the brake caliper.

Caution: Do not place your fingers in front of the piston in order to catch or protect the piston while applying compressed air. This could result in serious injury.

Notice: Use clean cloths to pad interior of caliper housing during piston removal. Use just enough air to ease the pistons out of the bores. If the pistons are blown out, even with the padding provided, it may be damaged.

8. Place a 25 mm (1 in) block of wood between the caliper and the piston.
9. Install a large C-clamp over the body of the brake caliper with the C-clamp ends against the rear of the caliper body and against the block of wood.
10. Carefully remove the brake caliper piston by directing low pressure compressed air into the brake caliper inlet hole.
11. Remove the C-clamp form the caliper.
12. Remove the block of wood from the caliper.
13. Install clean cloths to pad the interior of the caliper housing between the remaining caliper piston and the caliper body.
14. To cover the open caliper bore place a 25 mm (1 in) block of wood between the caliper body and the brake caliper dust boot seal.
15. Install a large C-clamp over the body of the brake caliper with the C-clamp ends against the rear of the caliper body and against the block of wood.
16. Carefully remove the brake caliper piston by directing low pressure compressed air into the brake caliper inlet hole.
17. Remove the C-clamp form the caliper.
18. Remove the block of wood from the caliper.




Important: Care must be used when removing the piston boot and seal from the caliper. Use a small plastic or wood tool for removal. Do not use a metal tool because it may damage the caliper bore or seal groove.

19. Remove the piston boots from the brake caliper.
20. Remove the piston seals from the brake caliper.
21. Remove the brake caliper bleeder valve and cap from the brake caliper.

Important: Do not use abrasives to clean the brake caliper piston.




22. Clean the brake caliper piston bore and seal counterbore, and the caliper piston with denatured alcohol, or equivalent.
23. Dry the caliper piston bores and counterbores, and the piston with non-lubricated, filtered air.
24. Inspect all of the brake caliper parts as follows.

•	Piston - Inspect for scoring, nicks, cracks, wear, or corrosion. Replace the pistons if any damage is found.

•	Caliper Bore - Inspect for scoring, nicks, cracks, wear, or corrosion. Use crocus cloth to polish out light corrosion. Otherwise, replace the caliper. Do not hone the caliper bore.

•	Seal groove in the caliper bore for nicks or burrs. If found, replace the caliper.

25. Install the brake caliper bleeder valve and bleeder valve cap into the brake caliper.
26. Lubricate the new piston seal with Delco Supreme 11® (GM P/N 12377967) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
27. Install the lubricated, new piston seals into the caliper bores.
28. Using a caliper piston dust boot seal installer, or equivalent tool, that will fully seat the dust boot seal for the seal counterbore diameter and the piston bore diameter specified.

Specification

•	Brake caliper piston dust boot seal counterbore diameter 71.96 mm (2.833 in).

•	Brake caliper piston bore diameter 56.5 mm (2.224 in).

29. Install the brake caliper to the vehicle. Refer to Front Brake Caliper Replacement .