GM Service Manual Online
For 1990-2009 cars only

Warning: Refer to Brake Fluid Irritant Warning in the Preface section.

Warning: Do not remove the reservoir cap while depressing and releasing the brake pedal. If the cap is removed while depressing and releasing the brake pedal, pressurized brake fluid being returned to the reservoir may leave the reservoir. Personal injury or vehicle damage could result.

Caution: Refer to Brake Fluid Effects on Paint and Electrical Components Caution in the Preface section.

Caution: When adding fluid to the brake master cylinder reservoir, use only Delco Supreme 11®, GM P/N 12377967 (Canadian P/N 992667), 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.

Caution: Do Not allow the HBCi pump and motor to run more than 1 minute continuously. Allow 2 minutes cool down time between pump run times. Extended pump and motor run time could create excessive heat, and damage the pump and motor assembly.

Note: Perform steps 1-4 below to bleed the HBCi accumulator circuit prior to performing a base brake bleed.

  1. Turn the ignition ON. Allow the pump and motor to run as required. The pump and motor will stop automatically, and may run up to 10 seconds.
  2. Depress the brake pedal 4 times.
  3. Confirm that brake fluid returns to the reservoir.
  4. Repeat steps 1-3 until all air is purged from the accumulator circuit (return fluid is clear and free from air).
  5. Note: The base hydraulic brake system must be bled before proceeding. If you have not yet performed the base hydraulic brake system bleeding procedure, refer to Hydraulic Brake System Bleeding for hydraulic brakes before proceeding.

  6. Turn the ignition OFF, wait 15 seconds then depress and release the brake pedal 20 times to deplete accumulator pressure. If the brake fluid clouds and has air mixed with the fluid, wait until the fluid clears to proceed.
  7. Turn the ignition ON and depress the pedal 20 times quickly. The pump and motor will be activated.
  8. Turn the ignition OFF, wait 15 seconds and repeat step 5 again. If the brake fluid clouds and has air mixed with the fluid, wait until the fluid clears to proceed.
  9. Turn the ignition ON to activate the pump and motor. Allow the pump and motor to stop automatically. The pump and motor will run about 10 seconds.
  10. Install a scan tool to the vehicle.
  11. Start the engine and allow the engine to idle.
  12. Depress the brake pedal firmly and maintain steady pressure on the pedal.
  13. Using the scan tool, begin the automated bleed procedure.
  14. Follow the instructions on the scan tool to complete the automated bleed procedure. Release the brake pedal between each test sequence.
  15. Turn the ignition OFF.
  16. Remove the scan tool from the vehicle.
  17. Fill the brake master cylinder reservoir to the maximum-fill level with Delco Supreme11® GM P/N 12377967 (Canadian P/N 992667) or equivalent DOT-3 brake fluid from a clean, sealed brake fluid container.
  18. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding for hydraulic brakes.
  19. With the ignition OFF, wait 15 seconds apply the brakes 20 times, or until the brake pedal becomes firm, in order to deplete the brake booster power reserve.
  20. Slowly depress and release the brake pedal. Observe the feel of the brake pedal.
  21. If the 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.
  22. Turn the ignition key ON, with the engine OFF; check to see if the brake system warning lamp remains illuminated.
  23. 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.
  24. Drive the vehicle to exceed 13 kph (8 mph) to allow ABS initialization to occur. Observe brake peal feel.
  25. If the brake pedal feels spongy, repeat the automated bleeding procedure until a firm brake pedal is obtained.