Brake Master Cylinder: Service and Repair

Removing And Installing Brake Master Cylinder

Removal







1. Remove cover -A- from the hydraulic unit/brake unit.







2. Drain brake fluid explansion tank. To do so, suck brake fluid out of the expansion tank or pump out the brake fluid using the brake pedal via a front and a rear brake caliper (use collecting bottle).
3. Disconnect the electrical line (plug) -arrow- on the reservoir (figure showing Boxster without PSM/with brake proportioning valve).
4. For vehicles with manual transmission, remove the clutch line at the reservoir.
- Press on the ring to do this (unlocking) and pull the line out of the reservoir at the same time.







5. Undo the brake lines on the brake master cylinder. Close the brake lines and the brake line connections with suitable plugs.
6. Undo the fastening nuts -A- of the brake master cylinder. Pull out the brake master cylinder ausfahren (figure of Boxster with PSM).

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

Installation
1. Install in reverse order.
2. Bleed the brakes Serv. No. 47 01 07 (vehicle with ABS and ABS/TC) and Serv. No. 47 01 07 - (vehicle with PSM).

NOTE:
- First bleed brakes as usual.
- Only after this (after the conventional bleeding) should the return pump actuation be performed (continue bleeding) with the Porsche System Tester 2 in vehicles with TC (Traction Control) or the booster pump control in the case of vehicles with PSM. If this is not observed, damage can occur to the return pump/booster pump.
- To bleed at rear on right with running return pump (TC) or at front right with running booster pump (PSM), the bleeding device remains connected (switched on). Bleeding pressure approximately 2.0 bar.

3. Bleed the clutch system (Serv. No. 30 01 07) for vehicles with manual transmission.
4. Carry out a function check of the brakes.