For 1990-2009 cars

Caution: Use only Delco Supreme 11, GM P/N 12377967 (Canadian P/N 992667), or equivalent DOT 3 brake fluid from a clean, sealed container. Do not use fluid from an open container that may be contaminated with water. Improper or contaminated fluid could result in damage to components, or loss of braking, with possible injury.

Caution: Use only SUPREME 11 or equivalent DOT 3 brake fluid from a clean, sealed container. Do not use fluid from an open container that may be contaminated with water. Improper or contaminated fluid will result in damage to components or loss of braking, with possible personal injury.

Caution: Do not overfill the brake fluid reservoir. Overfilling the brake fluid reservoir may cause the brake fluid to overflow onto the engine exhaust components during brake system service. The brake fluid is flammable and may cause a fire and personal injury if the brake fluid contacts the engine exhaust system components.

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.

Notice: Brake fluid will damage electrical connections and painted surfaces. Use shop cloths, suitable containers, and fender covers to prevent brake fluid from contacting these areas. Always re-seal and wipe off brake fluid containers to prevent spills.

A bleeding operation is necessary in order to remove air when air is introduced into the hydraulic brake system.

Bleed the hydraulic system at all four brakes if air has been introduced through a low fluid level or by disconnecting brake pipes at the master cylinder. If a brake hose or brake pipe is disconnected at one wheel, bleed only that one wheel caliper. If brake pipes or hoses are disconnected at any fitting located between the master cylinder and the brakes, then only bleed the brake system served by the disconnected pipe or hose.

### With Scan Tool (Preferred Method)

1. Using a scan tool, select the Motor Rehome under special functions. The Motor Rehome function cannot be performed if current DTCs are present. If DTCs are present, repair the vehicle fault and clear the DTCs before performing the Motor Rehome function.
2. Bleed the entire brake system.

### Without Scan Tool

Important: Do not place your foot on the brake pedal through this entire procedure unless specifically directed to do so.

1. Remove foot from the brake pedal.
2. Start the engine. Allow the engine to run for at least 10 seconds while observing the amber ABS warning indicator.
3. If the amber ABS warning indicator turns on and stays on after 10 seconds, stop the bleeding procedure. Use a scan tool in order to diagnose the ABS malfunction.
4. If the amber ABS warning indicator turns on for approximately 3 seconds, then turns off and stays off, turn the ignition off.
5. Repeat the previous 4 steps again.
6. Bleed the entire brake system.

### Pressure Bleeding

#### Tools Required

• | J 29532 Diaphragm Type Brake Bleeder

• | J 35589 Compact Brake Bleeder 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, oil and other contaminants from entering the hydraulic system.

1. Remove the battery tray.
2. Clean the brake fluid reservoir cover and the surrounding area.
3. Remove the brake fluid reservoir cover.
4. Inspect the brake fluid reservoir level. Refer to Master Cylinder Reservoir Filling . Add clean brake fluid as required.
5. Connect the J 35589 to the brake fluid reservoir.
6. Install the J 29532 to the pressure bleeding equipment.
7. Adjust the pressure bleed equipment to 242 kPa (35 psi).

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.

8. Bleed the brake pipe connections on the brake proportioning valve using pressure bleeding equipment that is connected and pressurized:

8.1. | Slowly open the tube nut on the bottom brake pipe on the brake proportioning valve. Inspect for air in the escaping fluid.

8.2. | When the air flow ceases, immediately tighten the tube nut.

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

8.3. | Moving from the bottom to the top, repeat the previous step for the top brake pipe connection.

9. Complete the following procedures using pressure bleeding equipment that is connected and pressurized:

9.1. | Attach a clear plastic bleeder hose to the rearward bleeder valve on the brake modulator.

9.2. | Submerge the opposite hose end in a clean container that is partially filled with clean brake fluid.

9.3. | Slowly open the bleeder valve. Allow the fluid to flow until no air is seen in the fluid.

9.4. | Close the valve when the fluid flows without any air bubbles.

| Important: Use a shop cloth in order to catch escaping brake fluid. Prevent the fluid from running down the motor pack case or into the electrical connector. Do not allow brake fluid to contact any painted surfaces as surface damage will occur. If brake fluid does contact any surface, flush the surface with water in order to lessen the damage.

9.5. | Repeat the previous 4 steps until no air bubbles are present.

9.6. | Relocate the bleeder hose on the forward brake modulator bleeder valve.

9.7. | Submerge the opposite hose end in a clean container partially filled with clean brake fluid.

9.8. | Slowly open the bleeder valve. Allow the fluid to flow until no air is seen in the fluid.

9.9. | Close the valve when the fluid flows without any air bubbles.

Tighten
Tighten the ABS modulator bleeder valves to 9 N·m (80 lb in).

10. Bleed the brake modulator brake pipe connections using pressure bleeding equipment that is connected and pressurized:

10.1. | Slowly open the tube nut on the forward brake pipe on the brake modulator. Inspect for air in the escaping fluid.

10.2. | When the air flow ceases, immediately tighten the tube nut.

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

10.3. | Moving from the front to the rear, repeat the previous 2 steps for the remaining 3 brake pipe connections.

11. Raise the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
12. Use the following bleed sequence in order to bleed the system:

• | Right rear

• | Left front

• | Left rear

• | Right front

13. Bleed the wheel brakes in the sequence shown above:

Important: Ensure that the bleeder valves do not leak.

14. Complete the following steps in order to bleed the brakes:

13.1. | Attach a clear plastic bleeder hose (3) to the bleeder valve at the wheel.

13.2. | Submerge the opposite hose end in a clean container (2) partially filled with clean brake fluid.

13.3. | Slowly open the bleeder valve and allow the fluid to flow.

13.4. | Close the valve when the fluid begins to flow without any air bubbles. Tap lightly on the caliper (1) or backing plate in order to dislodge any trapped air bubbles.

Tighten

• | Tighten the front caliper bleeder valves to 13 N·m (115 lb in).

• | Tighten rear caliper bleeder valves to 7 N·m (62 lb in).

• | Tighten the rear wheel cylinder bleeder valves to 7 N·m (62 lb in).

15. Lower the vehicle.
16. Remove the J 29532 and the J 35589 .
17. Inspect the brake fluid level in the reservoir (1). Fill the reservoir to the proper level if necessary.
18. Reinstall the brake fluid reservoir cap.
19. Install the battery tray.
20. Cycle the ignition to the ON then OFF position. Do not start the engine.
21. Apply the brake pedal with moderate force and hold the brake pedal. Note the pedal travel and feel.
22. 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. If the pedal travel is still firm and constant and pedal travel is not excessive, perform a road test on the vehicle. Make several normal (non-ABS) stops from a moderate speed in order to ensure proper brake system function. Allow adequate cooling time between stops.
24. If pedal travel feels soft or has excessive travel either initially or after the engine start, use the following procedure:

23.1. | Using the scan tool, release then apply each motor 2-3 times and cycle each solenoid 5-10 times.

23.2. | When finished, perform the motor rehome procedure to ensure the pistons are in the upmost position.

23.3. | If a scan tool is not available, remove your foot from the brake pedal. Start the engine and allow the engine to run for at least 10 seconds in order to initialize the ABS. Do not drive the vehicle.

23.4. | After 10 seconds, turn the ignition off.

23.5. | Repeat the initialization procedure 5 times in order to ensure that any trapped air has been dislodged. Repeat the pressure bleeding procedure starting at Step 1.

25. Perform a road test on the vehicle. Make several normal (non-ABS) stops from a moderate speed in order to ensure proper brake system function. Allow adequate cooling time between stops.