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

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

1. Turn the ignition switch to the OFF position.
2. Clean the electronic brake control module (EBCM) to brake pressure modulator valve (BPMV) area and the brake pipe port areas of any accumulated dirt and foreign material.



3. Disconnect the brake fluid level indicator switch electrical connector.
4. Disconnect the vacuum brake booster vacuum sensor electrical connector.



5. Remove the vacuum brake booster check valve and vacuum sensor assembly from the grommet and position aside.



6. Release the wiring harness retainer from the master cylinder mounting stud and position the wiring harness downward.
7. Remove and discard the 2 master cylinder nuts.
8. If equipped, disconnect the clutch master cylinder hose from the brake master cylinder reservoir.

Cap the brake fluid reservoir outlet and plug the clutch master cylinder hose inlet to prevent brake fluid loss and contamination.




9. Remove the 2 master cylinder brake pipe fittings from the BPMV.

Cap the brake pipe fittings and plug the BPMV inlet ports to prevent brake fluid loss and contamination.

10. Remove the brake master cylinder and master cylinder brake pipes as an assembly.



11. Lift the locking tabs on the lower edge of the EBCM electrical connector (1)  and disconnect the electrical connector.
12. Position the EBCM electrical connector and the wiring harness toward the front of the vehicle.
13. Release the rear brake pipes retainer (2) from the outboard side of the frame rail.



14. Remove the 3 BPMV bracket bolts.
15. Carefully position the brake modulator assembly forward slightly.



16. Remove the vacuum brake booster pushrod retaining clip.
17. Remove the vacuum brake booster pushrod spacer.



18. Disconnect the vacuum brake booster pushrod (1) from the brake pedal pushrod pin.
19. Remove the 4 vacuum brake booster mounting nuts (2).
20. Remove the vacuum brake booster from the vehicle.

1. Inspect the vacuum brake booster to dash panel seal (1) for damage and replace, if necessary.
2. Inspect the vacuum brake booster to dash panel gasket (2) for damage and replace, if necessary.
3. Install the vacuum brake booster (3) to the vehicle.

Notice: Refer to Fastener Notice in the Preface section.




4. Connect the vacuum brake booster pushrod (1) to the brake pedal pushrod pin.
5. Install the 4 vacuum brake booster mounting nuts (2).

Tighten
Tighten the nuts to 25 N·m (18 lb ft).




6. Apply a thin coat of high-temperature grease GM P/N 12345996 (Canadian P/N 10953501) to the vacuum brake booster pushrod spacer and the brake pedal pushrod pin.
7. Install the vacuum brake booster pushrod spacer.
8. Install the vacuum brake booster pushrod retaining clip.



9. Carefully position the brake modulator assembly to the frame rail.
10. Install the 3 BPMV bracket bolts.

Tighten
Tighten the bolts to 10 N·m (89 lb in).




11. Position the EBCM electrical connector and the wiring harness to the EBCM.
12. Connect the EBCM electrical connector (1) . Ensure the tabs on the cam lever are securely locked in place.
13. Install the rear brake pipes retainer (2) to the outboard side of the frame rail.



14. Install the brake master cylinder and master cylinder brake pipes assembly to the vacuum brake booster.
15. Install the master cylinder brake pipe fittings to the BPMV.

Tighten
Tighten the brake pipe fittings to 20 N·m (15 lb ft).




16. If equipped, connect the clutch master cylinder hose to the brake master cylinder reservoir.
17. Install 2 new brake master cylinder nuts.

Tighten
Tighten the nuts to 20 N·m (15 lb ft).

18. Position the wiring harness upward and install the wiring harness retainer to the master cylinder mounting stud on the vacuum brake booster.

Important: If necessary, a small amount of denatured alcohol can be used as an assembly aid for installing the check valve to the vacuum brake booster grommet. Do not use soap.




19. Install the vacuum check valve and vacuum sensor assembly to the vacuum brake booster.



20. Connect the brake booster vacuum sensor electrical connector.
21. Connect the brake fluid level indicator switch electrical connector.
22. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding .
23. Calibrate the brake pedal position sensor. Refer to Brake Pedal Position Sensor Calibration .