34 51 527 Removing and installing/replacing hydraulic unit for DSC (M54 / N62 / N52)
WARNING: This page is about a different car, the 2005 BMW 645Ci and 2004 BMW 645Ci. However, it is still accessible from the selected car via links, so may be relevant.
Necessary preliminary tasks:
- Before removing hydraulic unit, read out control unit fault memory and if necessary print out diagnostic trouble code.
- Read and comply with General Information, refer to 34 00 ... GENERAL INFORMATION .
After completing tasks, bleed brake system, refer to 34 00 025 REPLACING FLUID IN ABS/ASC+T BRAKE SYSTEM .
Installation:
When replacing the control unit, carry out the following tasks with the DIS (Diagnosis and Information System):
- Vehicle coding (performed by the vehicle itself)
- Adjustment of steering angle sensor (performed by the vehicle itself)
- Adjustment of brake pressure sensor (performed by the vehicle itself)
- Adjustment of lateral acceleration sensors (performed by the vehicle itself)
- Mix-up check of brake lines
- Function check, hydraulic unit
Apply pedal prop and depress brake pedal slightly. This prevents brake fluid from emerging from the expansion tank and air from entering the brake system after the brake lines have been detached.
IMPORTANT:
Do not mix up brake pipes (mark if necessary). Seal off connection bores with plugs.
Unfasten plug connection (1).
Unfasten brake lines (2).
Installation:
Tightening torque, refer to 34 32 1AZ in BRAKES - TIGHTENING TORQUES - 645CI .
IMPORTANT:
Do not bend brake lines.
Release screw (3) and remove hydraulic unit.
When replacing hydraulic unit:
Release screws (1) and convert holder (2).