GM Service Manual Online
For 1990-2009 cars only

Notice: If any brake component is repaired or replaced such that air is allowed to enter the brake system, the entire bleeding procedure must be followed.

Notice: Prior to bleeding the brakes, the front and rear displacement cylinder pistons must be returned to the topmost position. The preferred method uses a Scan Tool to perform the rehoming procedure. If a Scan Tool is not available, the second procedure may be used, but it is extremely important that the procedure be followed exactly as outlined.

Pressure Bleeding

Tools Required

J 35589 Bleeding Adapter

Notice: Pressure bleeding equipment must be of the diaphragm type. It must have a rubber diaphragm between the air supply and the brake fluid to prevent air, moisture, and other contaminants from entering the hydraulic system.

  1. Clean the fluid reservoir cover and the surrounding areas.
  2. Ensure that the master cylinder reservoir is at the proper level. Refer to Master Cylinder Reservoir Filling . Add clean brake fluid as required.
  3. Install the J 35589 to brake fluid reservoir.
  4. Install the J 35589 to the pressure bleeding equipment.
  5. Attach a clear plastic hose to the rearward bleeder valve on the hydraulic modulator.
  6. Submerge the other end of the bleeder hose in a clean container partially filled with brake fluid.
  7. Adjust the pressure bleeding equipment to 35--70 kPa (5--10 psi). Wait for approximately 30 seconds in order to ensure that there is no leakage.
  8. Adjust the pressure bleeding equipment to 205--240 kPa (30--35 psi).

  9. Complete the following steps using pressure bleeding equipment that is connected and pressurized:
  10. 8.1. Connect the bleeder hose to the rearward bleeder valve on the hydraulic modulator.
    8.2. Slowly open the bleeder valve. Allow the fluid to flow until no air is seen in the fluid.
    8.3. Close the valve when the fluid flows without any air bubbles.
    8.4. Repeat the previous two steps until no air bubbles exist.
    8.5. Relocate the bleeder hose on the forward bleeder valve on the hydraulic modulator.
  11. Attach a clear plastic hose to the forward bleeder valve.
  12. Submerge the other end of the bleeder hose in a clean container partially filled with brake fluid.
  13. Adjust the pressure bleeding equipment to 35--70 kPa (5--10 psi). Wait for approximately 30 seconds in order to ensure that there is no leakage.
  14. Adjust the pressure bleeding equipment to 205--240 kPa (30--35 psi).

  15. Complete the following steps using pressure bleeding equipment that is connected and pressurized:
  16. 12.1. Connect the bleeder hose to the forward bleeder valve on the hydraulic modulator.
    12.2. Slowly open the bleeder valve. Allow the fluid to flow until no air is seen in the fluid.
    12.3. Close the valve when the fluid flows without any air bubbles.

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    12.4. Repeat the previous two steps until no air bubbles exist.

    Tighten
    Tighten the hydraulic modulator bleeder valve to 9 N·m (80 lb in).

    Important: Use a shop cloth in order to catch escaping brake fluid. Do not allow the fluid to run down the motor pack and into the bottom or the electrical connector. Do not use a bleeder hose in order to bleed the brake pipe connections.

  17. Bleed the hydraulic modulator brake pipe connections as follows using pressure bleeding equipment that is connected and pressurized.
  18. 13.1. Slowly open the forward brake pipe tube nut on the hydraulic modulator. Inspect for any escaping fluid.
    13.2. When the air flow ceases, immediately tighten the tube nut.

    Tighten
    Tighten the tube nut to 23 N·m (17 lb ft).

    13.3. Repeat the previous two steps for the remaining three brake pipe connections, moving from the front to the rear.
  19. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  20. Important: Bleed the wheel brakes in the following sequence:

       • Right rear
       • Left rear
       • Right front
       • Left front

  21. Attach the bleeder hose to the bleeder valve.
  22. Submerge the opposite hose end in a clean container that is partially filled with brake fluid.
  23. Slowly open the bleeder valve and allow the fluid to flow.
  24. Close the valve when the fluid begins to flow without any air bubbles. Tap lightly with a rubber mallet in order to dislodge any trapped air bubbles.
  25. Lower the vehicle.
  26. Remove the J 35589 .
  27. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level using clean brake fluid, if necessary.
  28. Install the fluid reservoir cover and diaphragm assembly.
  29. Inspect the pedal travel and feel. Complete the following steps:
  30. 23.1. With the ignition switch in the Run position, apply the brake pedal with moderate force and hold the pedal.
    23.2. Note the pedal travel and feel. If the pedal feels firm and constant and pedal travel is not excessive, start the engine. With the engine running, re-check the pedal travel.
    23.3. If the pedal travel is still firm and constant and the pedal travel is not excessive, road test the vehicle. Make several normal (non-ABS) stops from a moderate speed in order to ensure the proper brake system function.
  31. If the pedal feels soft or has excessive travel either initially or after engine start, complete the following steps:
  32. 24.1. Using the Scan Tool, release then apply the ABS motors 2 to 3 times, and cycle the solenoids 5 to 10 times
    24.2. Apply the front and rear ABS motors in order to ensure that the pistons are in the upper most position.
    24.3. Repeat the entire pressure bleeding procedure.
  33. Road test the vehicle. Make several normal (non-ABS) stops from a moderate speed in order to ensure the proper brake system function.

Manual Bleeding

Important: Use a suitable container and/or shop rags in order to catch the fluid and prevent it from contacting any painted surfaces.

Clean the fluid reservoir cover and the surrounding areas.

Inspect the fluid level in the reservoir and fill to the correct level if necessary.

  1. Clean the fluid reservoir cover and the surrounding area.
  2. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level, if necessary.
  3. Install the fluid reservoir cover.
  4. Attach the bleeder hose to the rearward bleeder valve on the hydraulic modulator.
  5. Submerge the opposite hose end in a clean container that is partially filled with brake fluid.

  6. Slowly open the rearward bleeder valve 1/2 to 3/4 turns.
  7. Depress the brake pedal and hold the pedal until the fluid begins to flow.
  8. Close the valve and release the brake pedal. Repeat the previous two steps until no air bubbles are present.
  9. Repeat the previous three steps until the fluid begins to flow.
  10. Relocate the bleeder hose to the forward hydraulic modulator bleeder valve.
  11. Submerge the opposite hose end in a clean container partially filled with brake fluid.
  12. Slowly open the rearward bleeder valve 1/2 to 3/4 turns.
  13. Depress the brake pedal and hold the pedal until the fluid begins to flow.
  14. Close the valve and release the brake pedal. Repeat the previous two steps until no air bubbles are present.
  15. Remove the fluid reservoir cover.
  16. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level, if necessary. Use clean brake fluid.
  17. Install the fluid reservoir cover.
  18. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
  19. Important: Bleed the wheel brakes in the following sequence:

       • Right rear
       • Left rear
       • Right front
       • Left front

  20. Attach the bleeder hose to the bleeder valve.
  21. Submerge the opposite hose end in a clean container partially filled with brake fluid.

  22. Open the bleeder valve.
  23. Slowly depress the brake pedal.
  24. Close the valve and slowly release the brake pedal.
  25. Wait 5 seconds.
  26. Repeat the previous five steps until the brake pedal feels firm at half travel and no air bubbles are observed in the bleeder hose.
  27. Tap lightly on the caliper or the braking plate in order to assist in freeing entrapped air.

  28. Lower the vehicle.
  29. Remove the fluid reservoir cover.
  30. Inspect the fluid level in the reservoir. Fill the reservoir to the correct level, if necessary.