34 51 525 Removing and installing/replacing hydraulic unit ABS/ASC+T, DSC3 from 09/98: Notes

NOTE: Note "General Information", 34 00...
Before removing the hydraulic unit, read out the fault memory of the control unit and if necessary print the fault code.
After finishing work:
Check function of hydraulic control unit.

Installation:

Bleed brake system,
ABS/ASC+T, refer to 34 00 048 BLEEDING BRAKE SYSTEM WITH ABS/ASC+T
DSC3, refer to 34 00 050 BLEEDING BRAKE SYSTEM WITH DSC3 750I/IL FROM 09/96 TO 09/98

Draw brake fluid out of expansion tank with a suction bottle reserved for exclusive use with brake fluid.

Fig 1: Drawing Brake Fluid Out Of Expansion Tank With Suction Bottle

Unlock fastener of plug connection (1) in direction (2). Vertically disconnect plug connection (1) in direction (3) upwards.

Installation:

Position plug connection (1) vertically on control module in order to avoid damaging pins.

Fig 2: Unlocking Fastener Of Plug Connection & Vertically Disconnecting Plug Connection

Unfasten brake lines.

CAUTION: Do not mix up brake lines, mark before removing if necessary.

Installation:

Line connections

Fig 3: Identifying Line Connections

(F) from THZ circuit F to hydraulic control unit circuit F (front-axle circuit)
(R) from THZ circuit R to hydraulic control unit circuit R (rear-axle circuit)
(FR) from hydraulic control unit FR to front right wheel brake (FL) from hydraulic control unit FL to front left wheel brake (RR) from hydraulic control unit RR to rear right wheel brake
(RL) from hydraulic control unit RL to rear left wheel brake

Observe Tightening Torque. Refer to BRAKES - TIGHTENING TORQUES .