Vacuum Brake Booster: Service and Repair

Power Vacuum Brake Booster Replacement

Removal Procedure

1. With the engine OFF, apply and release the brake pedal several times until the pedal becomes firm to deplete the power vacuum brake booster vacuum reserve.

2. Without draining the coolant and without disconnecting the hoses, position aside the radiator surge tank. Refer to Radiator Surge Tank Replacement Radiator Surge Tank Replacement.

3. Disconnect the brake pedal position sensor electrical connector. Refer to Brake Pedal Position Sensor Replacement Service and Repair.




4. Release the brake pedal (1) from the power vacuum brake booster pushrod by lifting the pedal upward.

Note: Do not reuse the brake pedal retainer.

5. Remove and discard the brake pedal retainer.

6. Disconnect the brake fluid level indicator switch electrical connector.

7. Release the brake fluid level indicator switch harness from the master cylinder reservoir clips and position aside, if necessary.




8. Disconnect the power brake booster vacuum sensor electrical connector.

9. Remove the power brake booster vacuum sensor (1) from the power vacuum brake booster.

Note: Do not disconnect the primary and secondary inlet brake pipe fittings.

10. Disconnect the front and rear brake pipe fittings and remove the brake pressure modulator valve (BPMV) assembly nuts from the BPMV assembly. Refer to Brake Pressure Modulator Valve Replacement Service and Repair.




11. Remove the master cylinder nuts (1).




12. Without disconnecting the BPMV primary and secondary brake pipe fittings, remove the master cylinder (1) and the BPMV as an assembly.




13. Inspect the master cylinder O-ring seal (1) for damage and replace, if necessary.




14. Completely loosen the power vacuum brake booster bolts (1).




15. Remove the power vacuum brake booster (1).

16. Inspect the power vacuum brake booster gasket (2) for damage and replace, if necessary.

Installation Procedure




1. Install the power vacuum brake booster (1) and gasket (2).





Caution: Refer to Fastener Caution Fastener Caution.

Note: Do not over tighten the power vacuum brake booster bolts. If the power vacuum brake booster bolts are over tightened, the brake pedal may remain applied after a high pressure brake pedal application.

2. Install the power vacuum brake booster bolts (1) and tighten to 19 Nm (14 lb ft).





Note: Ensure the master cylinder O-ring seal is properly seated in the groove in the master cylinder body and is not distorted.

3. Install the master cylinder O-ring seal (1).




4. Install the master cylinder (1) and the BPMV assembly.




5. Install the master cylinder nuts (1) and tighten to 50 Nm (37 lb ft).

6. Install the BPMV assembly nuts and the front and rear brake pipe fittings. Refer to Brake Pressure Modulator Valve Replacement Service and Repair.





Note: A small amount of alcohol may be used as a lubricant. Do not use soap.

7. Install the power brake booster vacuum sensor (1) to the power vacuum brake booster.

8. Connect the power vacuum brake booster vacuum sensor electrical connector.

9. Install the brake fluid level indicator switch harness to the master cylinder reservoir clips, if necessary.

10. Connect the brake fluid level indicator switch electrical connector.





Note: Install a new power vacuum brake booster pushrod retainer.

11. Install a new power vacuum brake booster pushrod retainer to the power vacuum brake booster pushrod.

Note: Ensure the power vacuum brake booster pushrod retainer is fully seated in the brake pedal arm.

12. Connect the power vacuum brake booster pushrod retainer (1) to the brake pedal.

13. Connect the brake pedal position sensor electrical connector. Refer to Brake Pedal Position Sensor Replacement Service and Repair.

14. Reposition the radiator surge tank. Refer to Radiator Surge Tank Replacement Radiator Surge Tank Replacement.