Front Brake Caliper Overhaul
Front Brake Caliper Overhaul (LFX)
Warning:
Refer to Brake Fluid Irritant Warning Brake Fluid Irritant Warning.
Warning:
Refer to Brake Dust Warning Brake Dust Warning.
Caution:
Refer to Brake Fluid Effects on Paint and Electrical Components Caution Brake Fluid Effects on Paint and Electrical Components Caution.
Disassembly Procedure
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.
Note:
* Replace all the components included in the repair kits used to service this brake caliper.
* Lubricate the rubber parts with GM approved brake fluid from a clean, sealed brake fluid container to make assembly easier.
* If any hydraulic component is removed or disconnected, it may be necessary to bleed all or part of the brake system.
* The torque values specified are for dry, non-lubricated fasteners.
* Perform the service operations on a clean bench, free from all mineral oil materials.
1. Remove the brake caliper from the vehicle. Refer to Front Brake Caliper Replacement (LFX) Front Brake Caliper ReplacementFront Brake Caliper Replacement (L99, LS3) Front Brake Caliper ReplacementFront Brake Caliper Replacement (LSA) Front Brake Caliper Replacement.
2. Drain the brake fluid from the brake caliper.
Caution:
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.
3. Place a 25 mm (1 in) block of wood between the caliper housing and the piston.
4. 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.
5. Carefully remove the brake caliper piston (1) by directing low pressure compressed air into the brake caliper inlet hole.
6. Remove the C-clamp from the caliper.
7. Remove the block of wood from the caliper.
8. Remove the piston dust boot seal (1) from the seal counterbore in the brake caliper and discard the dust boot seal.
9. Using a small wooden or plastic tool, remove the piston seal (1) from the brake caliper bore and discard the piston seal.
10. Remove the brake caliper bleeder valve cap (1) and bleeder valve (2).
Note:
Do not use abrasives to clean the brake caliper pistons.
11. Inspect the brake caliper mounting bracket guide surfaces for corrosion and wear. Remove and replace the brake caliper mounting bracket if damaged or worn.
12. Clean the brake caliper piston bores and seal counterbore with denatured alcohol, or equivalent.
13. Clean the brake caliper piston with denatured alcohol, or equivalent.
14. Dry the caliper piston bore and counterbore with non-lubricated, filtered air.
15. Dry the brake caliper piston with non-lubricated, filtered air.
16. Inspect the caliper bore for cracks, scoring, pitting, excessive corrosion.
17. If light corrosion is present in the caliper bore, attempt to remove the imperfection with a fine emery paper. If the imperfection cannot be removed, replace the caliper assembly.
18. If cracks, scoring, pitting, and excessive corrosion are present in the caliper bore, replace the caliper assembly.
19. Inspect the caliper piston for cracks, scoring, and/or damage. Replace the caliper piston if any of these conditions exist.
Assembly Procedure
Caution:
Refer to Fastener Caution Fastener Caution.
1. Install the brake caliper bleeder valve (2) and tighten to 10 Nm (89 lb in).
2. Install the brake caliper bleeder valve cap (1).
3. Lubricate the new piston seal (1) with GM approved brake fluid from a clean, sealed brake fluid container.
4. Install lubricated piston seal into the brake caliper bore seal groove.
Ensure the seal is not twisted.
5. Install the piston dust boot seal (1) to the caliper.
Ensure the seal is seated evenly and completely into the groove in the caliper housing.
6. Place the caliper piston into the caliper housing by carefully lifting the edge of the dust boot seal.
7. Carefully push the piston (1) squarely into the brake caliper bore.
8. Ensure the caliper dust boot is properly seated into the piston groove and into the groove in the brake caliper bore.
9. Install the brake caliper to the vehicle. Refer to Front Brake Caliper Replacement (LFX) Front Brake Caliper ReplacementFront Brake Caliper Replacement (L99, LS3) Front Brake Caliper ReplacementFront Brake Caliper Replacement (LSA) Front Brake Caliper Replacement.