Vacuum Brake Booster: Service and Repair

Brake Booster









Removal and Installation

1. Relieve the vacuum in the brake booster by pressing and releasing the brake pedal a minimum of 5 times with the engine not running.

2. Remove the Air Cleaner (ACL) element.

3. Remove the 2 bolts and position the coolant expansion tank/lower ACL (Air Cleaner) housing assembly aside.
- To install, tighten bolts to 15 Nm (133 lb-in).






4. Disconnect the brake fluid level switch.

5. If equipped, position the vacuum sensor wiring harness and front axle vent hose aside.

6. NOTICE: When the master cylinder is removed, the piston will be exposed. Do not damage the piston or piston surface or a fluid leak may occur.
Remove the 2 brake master cylinder nuts and position the master cylinder aside.
- Support the master cylinder with mechanic's wire.

- To install, tighten the nuts to 25 Nm (18 lb-ft).


7. NOTE: To allow proper drainage of any moisture, the vacuum sensor must be installed in the same position and orientation as removed.
Disconnect the vacuum sensor assembly from the brake booster.


8. NOTICE: Do not service the brake pedal or brake booster without first removing the stoplamp switch. This switch must be removed with the brake pedal in the at-rest position. The switch plunger must be compressed for the switch to rotate in the bracket. Attempting to remove the switch when the plunger is extended (during pedal apply) will result in damage to the switch.
Remove the stoplamp switch.

9. NOTE: The booster push rod clevis-locking pin is a one-time use only part. Any time the booster push rod clevis-locking pin is removed, a new booster push rod clevis-locking pin should be used.
NOTE: Remove the clevis-locking pin by squeezing the locking tabs and pulling outward on the opposite end.
Remove and discard the booster push rod clevis-locking pin.


10. Remove the 4 brake booster nuts and remove the brake booster.
- To access the nuts, fold back the sound insulation.

- To install, tighten the nuts to 25 Nm (18 lb-ft) following a clockwise pattern starting with the upper left nut.


11. NOTICE: Do not press, pull or otherwise move the brake pedal while installing the stoplamp switch. This switch must be installed with the booster push rod attached to the brake pedal and with the brake pedal in the at-rest position. Installing this switch with the brake pedal in any other position will result in incorrect adjustment and may damage the switch.
To install, reverse the removal procedure.