Replacing the brake booster (Opel Astra J)

The vacuum brake booster is a complex, difficult to disassemble structure. Its adjustment and repair require qualified personnel and special equipment. In addition, the booster is a device that directly affects traffic safety, low-quality repair can lead to serious consequences, so in case of a malfunction, replace the booster as a whole.

Methods for checking the performance of the brake booster are described above in this section (see Checking the operation of the brake booster).

You will need: wrenches "13", "17", "15" or a special wrench "15" for brake pipes, socket head "13", pliers, screwdriver with a flat blade.

Note: The nuts that hold the brake pipes are usually very tight. When trying to loosen them with a regular wrench, the edges of the nuts are crushed, so we recommend using special wrenches for brake pipes.

1. Disconnect the wire from the negative terminal of the battery.



2. Remove the battery (see Removal and installation the battery)…





3. …and the shelf for its fastening (see Removal and installation the battery mounting shelf).



4. Remove the brake master cylinder (see Replacing the master brake cylinder).



5. Disconnect the wiring harness connector from the check valve by pressing its spring clip.



6. Loosen the clamp that secures the hose to the valve on the inlet pipe by squeezing its bent ears with pliers..





7. ...slide the clamp along the hose..



8. …and disconnect the hose from the valve fitting.



9. Remove the vacuum pump hose from the holder…



10. … remove the valve from the hole in the sealing sleeve of the brake booster and move it to the side without disconnecting the hose to the vacuum pump.





11. Remove the two vacuum booster mounting bolts…

[Original article on the web portal: opelbook]



12. …remove the bolts from the holes in the front shield and the amplifier housing...

Note: This is how the vacuum booster mounting bolts are located.

13. …and remove the amplifier into the engine compartment.

Note: The tip of the brake booster rod is inserted into a special stop on the brake pedal and is not secured in it in any way.

14. If replacing the vacuum booster, remove the sealing gasket from it and install it on the new booster.

Note: Replace a gasket that is severely compressed or torn.

15. Install the brake booster and all removed parts in the reverse order of removal. Fill the brake fluid and bleed the system (see Bleeding the hydraulic brake system).

Note: Be sure to replace the rubber sealing ring of the brake master cylinder flange with a new one.