Sierra 1500 2WD V6-4.3L (2008)
Brake Bleeding: Service and Repair
Antilock Brake System Automated Bleed Procedure
Antilock Brake System Automated Bleed
Notice: Avoid spilling brake fluid onto painted surfaces, electrical connections, wiring, or cables. Brake fluid will damage painted surfaces and cause
corrosion to electrical components. If any brake fluid comes in contact with painted surfaces, immediately flush the area with water. If any brake fluid
comes in contact with electrical connections, wiring, or cables, use a clean shop cloth to wipe away the fluid.
Important: The base hydraulic brake system must be bled before performing this automated bleeding procedure. If you have not yet performed the base
hydraulic brake system bleeding procedure, refer to Hydraulic Brake System Bleeding before proceeding.
1. Install a scan tool to the vehicle.
2. Start the engine and allow the engine to idle.
3. Using the scan tool, begin the automated bleed procedure.
4. Follow the instructions on the scan tool to complete the automated bleed procedure. Apply the brake pedal when instructed by the scan tool.
5. Turn the ignition OFF.
6. Remove the scan tool from the vehicle.
7. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme 11, GM P/N 12377967 (Canadian P/N 992667), or
equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
8. Bleed the hydraulic brake system.
9. With the ignition OFF, apply the brakes 3-5 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
10. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
11. If the brake pedal feels spongy, repeat the automated bleeding procedure. If the brake pedal still feels spongy after repeating the automated
bleeding procedure inspect the brake system for external leaks. Refer to Brake System External Leak Inspection. See: Testing and
Inspection/Component Tests and General Diagnostics/Brake System External Leak Inspection
12. Turn the ignition key ON, with the engine OFF; check to see if the brake system warning lamp remains illuminated.
13. If the brake system warning lamp remains illuminated, DO NOT allow the vehicle to be driven until it is diagnosed and repaired. Refer to
Symptoms - Hydraulic Brakes. See: Testing and Inspection/Symptom Related Diagnostic Procedures
14. Drive the vehicle to exceed 13 km/h (8 mph) to allow ABS initialization to occur. Observe brake pedal feel.
15. If the brake pedal feels spongy, repeat the automated bleeding procedure until a firm brake pedal is obtained.
