Low Brake Pedal, Red Brake Light On, Brake System Warning Message On (Tighten Rear Brake Caliper Banjo Bolts, Replace Gaskets and Install Shields)

This bulletin is being revised to add additional model years. Please discard Corporate Bulletin Number 04-05-23-001 (Section 05 -- Brakes).

Some customers may comment on a low brake pedal, red brake light on or the brake system warning message is on.

Under some extreme off-road conditions, debris may loosen the rear brake caliper banjo bolts causing a brake fluid leak.

Follow the service procedure below to inspect the rear brake caliper banjo bolts and gaskets and to install new slide bolts and rear caliper shield.

1. Verify the customer's concern.
2. Open the hood and install fender covers.
3. Clean off the brake master cylinder reservoir with brake clean, P/N 12378392 (in Canada, 88901247), or equivalent.
4. Visually inspect the brake fluid level through the brake master cylinder reservoir.

•	If the brake warning light is on and the fluid level is low, continue with the next step.

•	If the brake warning light is on and the fluid level is NOT low, continue with Brake Warning Indicator Always On diagnostic (SI Document ID #699182).

5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information (SI Document ID #737224).
6. Remove the tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #800427).
7. Inspect the rear brake calipers for signs of fluid leaks around the banjo bolt area on both rear calipers.
8. Clean off the banjo bolt area with brake clean, P/N 12378392 (in Canada, 88901247), or equivalent.

Important: The banjo bolts copper gasket should not be reused. The banjo bolts may be reused if not damaged.

9. Remove the banjo bolt and discard the copper gaskets.
10. Assemble the two new copper brake hose gaskets and the brake hose to caliper bolt to the brake hose.

Important: Inspect both rear caliper banjo bolt torques even if only one side is leaking.

Tighten
Tighten the bolt to 40 N·m (30 lb ft).

Notice: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11®, P/N 12377967 (Canadian P/N 89021320), or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container. The use of any type of fluid other than the recommended type of brake fluid may cause contamination, which could result in damage to the internal rubber seals and/or rubber linings of hydraulic brake system components.

11. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding in Hydraulic Brakes.

•	Hydraulic Brake System Bleeding Manual (SI Document ID #745273)

•	Hydraulic Brake System Bleeding Pressure (SI Document ID #745275)

12. Remove the caliper bracket bolts.
13. Reposition the caliper and bracket on top of the rear leaf spring.



14. Remove the caliper guide pin bolts.
15. Install the two new brake caliper guide pin bolts from the Shield Kit, P/N 15188166.

Tighten
Tighten the caliper guide pin bolts to 108 N·m (80 lb ft).




16. Install one shield and two nuts from the shield kit.

Tighten
Tighten the shield retaining nuts to 45 N·m (33 lb ft).

17. Install the caliper and bracket onto the rotor.
18. Install the caliper bracket bolts.

Tighten

•	For RPO JH5, tighten the caliper bracket bolts to 200 N·m (148 lb ft).

•	For RPO JH6/JH7, tighten the caliper bracket bolts to 299 N·m (221 lb ft).

19. Repeat this procedure on the opposite side of the vehicle.
20. Install the tire and wheel assembly. Refer to Tire and Wheel Removal and Installation in Tires and Wheels (SI Document ID #800427).
21. Lower the vehicle.
22. Top off the brake fluid reservoir.
23. Remove the fender covers and close the hood.
24. Road test the vehicle.

Parts are currently available from GMSPO.

For vehicles repaired under warranty, use: