Removing and Installing Hydraulic Unit

Removal
1. Switch off ignition. Remove cover for hydraulic unit.
2. Hold down brake pedal with pedal holder so that the brake fluid does not run out of the reservoir completely.
3. To remove the hydraulic unit, carry out the following removal procedure:
Undo the hydraulic lines on the hydraulic unit. Remove the lines between the brake master cylinder intermediate piston circuit and the hydraulic unit.
Unlock/disconnect the plug on the hydraulic unit.
Undo the 2 fastening nuts (arrows) and push hydraulic unit 5 out of holder 5a.





Note Close the lines and the hydraulic unit connections with suitable plugs.

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

Note After conventional bleeding, the ABD circuit must then be bled for vehicles with TC. The Porsche System Tester (PST 2) is required for this.

3. Check electrical and hydraulic lines (brake lines) for incorrect assignment using the Porsche System Tester 2.

Note The test checks that the brake lines/solenoid valves are assigned to the correct brake calipers (wheels). To do this, carry out a system test on vehicles with ABS or ABS/TC see Diagnosis/troubleshooting System ABS 5.3 or System ABS/TC 5.3.

4. When replacing the hydraulic unit in vehicles with ABS/TC (4-channel system), code the control module (manual transmission or Tiptronic).
5. Check brakes and ABS for correct functioning. Perform a short test drive to do this, and carry out at least one ABS control operation while taking into account the traffic situation. Then read out the fault memory.