Diesel Data: Automotive Repair

Vacuum Brake Booster: Service and Repair

Brake Booster

Brake Booster:





Removal and Installation

All vehicles
1. Remove the hydraulic control unit (HCU).

Partial zero emission vehicles (PZEV)
2. Remove the evaporative emission (EVAP) canister purge valve. For additional information, refer to Evaporative Emissions System.

All vehicles
3. Disconnect the heater hose bracket pin-type retainer from the cowl.





4. Remove the brake master cylinder.

CAUTION: Do not service the brake pedal or brake booster without first removing the stoplamp switch and speed control deactivator switch. These switches must be removed with the brake pedal in the at-rest position. Switch plungers 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.

5. Remove the stoplamp switch.
6. Disengage the tabs and remove the brake booster actuating rod pin.
^ Discard the brake booster actuating rod pin.
^ Disconnect the brake booster actuating rod from the brake pedal.

7. Remove the brake booster retaining nuts.
^ To install, tighten to 23 Nm (17 lb-ft).

8. Remove the brake booster.

9. CAUTION: Do not press, pull or otherwise move the brake pedal while installing the stoplamp switch or the speed control deactivator switch. These switches must be installed with the booster push rod attached to the brake pedal and with the brake pedal in the at-rest position. Installing these switches with the brake pedal in any other position will result in incorrect adjustment and may damage the switches.

To install, reverse the removal procedure.
^ Make sure the brake booster gasket is correctly positioned on the brake booster before installation.
^ Make sure that the brake booster actuator rod is correctly positioned through the bulkhead rubber boot.
^ Install a new brake booster actuating rod pin.