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Vacuum Brake Booster: Service and Repair



Power Vacuum Brake Booster Replacement

Removal Procedure
Caution: Refer to Brake Fluid Irritant Caution (Brake Fluid Irritant Caution).

Notice: Refer to Brake Fluid Effects on Paint and Electrical Components Notice (Vehicle Damage Warnings).

1. Relieve fuel line pressure. Refer to Fuel Pressure Relief (With CH 48027) (Fuel Pressure Relief (With CH 48027))Fuel Pressure Relief (Without CH 48027) (Fuel Pressure Relief (Without CH 48027)).
2. Drain the cooling system. Refer to Cooling System Draining and Filling (Static Fill LZ9) (Service and Repair)Cooling System Draining and Filling (Vac-N-Fill) (Service and Repair).
3. Remove the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement (Service and Repair).
4. Remove the left front cross brace. Refer to Front End Sheet Metal Diagonal Brace Replacement (Pontiac) (Service and Repair)Front End Sheet Metal Diagonal Brace Replacement (Chevrolet) (Service and Repair).
5. Remove the engine control module (ECM) cover from the air cleaner housing.
6. Remove the ECM and set aside. It is not necessary to disconnect the electrical connector. Refer to Engine Control Module Replacement (Service and Repair).
7. Remove the air cleaner assembly. Refer to Air Cleaner Assembly Replacement (Service and Repair).
8. Remove the fuel lines from the pipes and vapor line. Refer to Metal Collar Quick Connect Fitting Service (Metal Collar Quick Connect Fitting Service) orPlastic Collar Quick Connect Fitting Service (Plastic Collar Quick Connect Fitting Service).
9. Remove the heater hose from the coolant cross over pipe and reposition out of the way. Refer to Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement (Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement).
10. Release the fuel lines from the shock tower for easier access to the brake pipes.
11. Disconnect the fluid level sensor switch from the brake master cylinder.
12. Disconnect the brake lines from the master cylinder and remove the master cylinder. Refer to Master Cylinder Replacement (Master Cylinder Replacement).
13. Remove the brake pressure modulator valve (BPMV) assembly and bracket. Refer to Brake Pressure Modulator Valve Replacement (Service and Repair).




14. Remove the brake booster vacuum hose from the vacuum brake booster check valve and position aside.
15. Remove the knee bolster. Refer to Knee Bolster Replacement (Service and Repair).




16. Remove the booster push pin retaining clip and washer from the brake pedal assembly.
17. Remove the brake booster push rod (2) from the brake pedal (1).




18. Remove the brake booster mounting nuts.
19. Rotate the engine forward to gain access to the brake booster. Refer to Rotating the Engine for Service Access (Procedures).
20. Remove the brake booster.

Installation Procedure

Caution: When replacing the power booster brake, make sure that the cruise control cable is not routed between the booster and the cowl. If the cable is damaged or pinched, it must be replaced. Failure to do this could result in personal injury.




1. Position the brake booster to the cowl and the mounting plate.

Notice: Refer to Fastener Notice (Fastener Notice).

2. Install the brake booster mounting nuts.

Tighten the brake booster mounting nuts to 25 N.m (18 lb ft).

3. Install the master cylinder. Refer to Master Cylinder Replacement (Master Cylinder Replacement).




4. Install the brake booster push rod (2) to the brake pedal (1).
5. Install the washer and the brake booster pushrod retaining clip.

Notice: Proper stoplamp switch adjustment is essential. Improper stoplamp switch adjustment may cause brake drag, heat buildup and excessive brake lining wear.

6. Calibrate the brake pedal position sensor. Refer to Brake Pedal Position Sensor Calibration (Programming and Relearning).
7. Install the knee bolster. Refer to Knee Bolster Replacement (Service and Repair).
8. Rotate the engine back and install the engine mounts, bolts, and nuts. Refer to Rotating the Engine for Service Access (Procedures).




9. Install the brake booster vacuum hose to the vacuum brake booster check valve.
10. Install the BPMV and bracket assembly. Refer to Brake Pressure Modulator Valve Replacement (Service and Repair).
11. Install the brake master cylinder and connect the brake lines. Refer to Master Cylinder Replacement (Master Cylinder Replacement).
12. Connect the fluid level sensor switch on the master cylinder.
13. Install the fuel pipes to the pipes shock tower.
14. Install the heater hose to the coolant cross over pipe. Refer to Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement (Heater Inlet Hose/Pipe and Heater Outlet Hose/Pipe Replacement).
15. Install the air cleaner assembly. Refer to Air Cleaner Assembly Replacement (Service and Repair).
16. Install the ECM. Refer to Engine Control Module Replacement (Service and Repair).
17. Install the ECM cover.
18. Install the left front cross brace. Refer to Front End Sheet Metal Diagonal Brace Replacement (Pontiac) (Service and Repair)Front End Sheet Metal Diagonal Brace Replacement (Chevrolet) (Service and Repair).
19. Install the coolant recovery reservoir. Refer to Coolant Recovery Reservoir Replacement (Service and Repair).
20. Fill and bleed the cooling system. Refer to Cooling System Draining and Filling (Static Fill LZ9) (Service and Repair)Cooling System Draining and Filling (Vac-N-Fill) (Service and Repair).
21. Bleed the hydraulic brake system. Refer to Hydraulic Brake System Bleeding (Pressure) (Service and Repair)Hydraulic Brake System Bleeding (Manual) (Service and Repair).

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