Vacuum brake booster — removal, inspection and installation (Peugeot 405)

Vacuum booster

Examination

1. Press the brake pedal several times with the engine off to create the same pressure close to atmospheric in the cavities of the vacuum booster.

2. At the same time, by the force applied to the pedal, determine if the valve body is sticking.

3. Stop the brake pedal in the middle of its travel and start the engine.

4. With a working vacuum booster, the brake pedal should go forward after starting the engine.

5. If the pedal does not move forward, check the fastening of the hose tip, the condition of the fastening of the tip flange in the amplifier, the condition of the hose and fitting.

Removing

1. Remove the negative terminal from the battery.

2. Remove wiper drive.

3. Disconnect the electrical connector from the brake fluid level sensor.



4. Remove the vacuum one-way valve from the vacuum booster.


5. Unscrew the two nuts securing the master brake cylinder to the vacuum booster and remove the master brake cylinder from the vacuum brake booster without disconnecting the brake pipes from it.

6. In the lower front part of the passenger compartment, on the driver's side, unscrew the floor covering from under the panel to facilitate access to the pedal.

7. If necessary, release the fastening bracket, and disconnect the clutch cable from the pedal.

8. Disconnect the connector from the brake light switch.

9. Remove the rubber suspension elements of the pedals.



10. Unscrew the nuts securing the vacuum booster to the bulkhead of the engine compartment.



11. Remove the vacuum booster together with the pedals into the engine compartment.




12. Unscrew the four nuts securing the vacuum booster to the pedals.

13. Remove vacuum booster with gasket.

Installation

1. Installation is carried out in the reverse order of removal, taking into account the following points.

2. Use a new gasket when installing the vacuum booster.

3. Install windshield wiper.

4. Check stoplight switch adjustment.