Front Brake Caliper Overhaul

Tools Required 

J 45515 Brake Caliper Piston Boot Seal Installer

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 (Canadian P/N 992667) 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
Fig 1: C-Clamp On Brake Caliper

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.
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
    Fig 2: Front Caliper Piston Seals

    
    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
Fig 3: Exploded View Of Brake Caliper Components

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 (Canadian P/N 10953488) 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. Install the caliper piston into the caliper bore
29. Install the new piston dust boot seal over the piston
30. Using the J 45515 , fully seat the piston dust boot seal in the caliper
31. Install the brake caliper to the vehicle. Refer to Front Brake Caliper Replacement