Brake Master Cylinder: Service and Repair

Removing and Installing Brake Master Cylinder


Removal





NOTE: The booster pump -1- remains fitted (installed) during removal and installation of the brake master cylinder.





1. Remove cover -A- from the hydraulic unit/brake unit.
2. Remove brake fluid from reservoir using suction.
3. Disconnect the electrical line (plug) on the reservoir.





4. Remove suction line of booster pump -2-.
5. Undo the brake lines on the brake master cylinder. Close the brake lines and the brake line connections with suitable plugs.





NOTE:
- -A- = Brake master cylinder fastening nuts
- -B- = Brake booster fastening screws (Torx)





6. Undo the fastening nuts -A- of the brake master cylinder. Pull out brake master cylinder.


Installation

1. Install in reverse order.
2. Bleed the brakes.

NOTE:
- First bleed brakes as usual.
- Do not carry out booster pump activation with the Porsche System Tester 2 until after this has been done (after conventional bleeding) as otherwise damage to the booster pump can occur.
- To bleed at front on right with running booster pump the bleeding device remains connected (switched on). Bleeding pressure approximately 2.0 bar.

3. Carry out a function check of the brakes.