Anti-lock braking system (ABS)

ELECTROHYDRAULIC UNIT

REMOVAL AND REFITTING

Before working on the brake hydraulic circuit or disconnecting a fitting, allow the fluid to drain and protect the surrounding area. Then plug all open ports with suitable caps.

• Disconnect the battery.
• Set the washer fluid reservoir aside without disconnecting the hoses.
• Using a syringe, draw out as much brake fluid as possible from the expansion reservoir.
• Disconnect the lines (1) (Fig.29) from the hydraulic unit.
• Unlock and disconnect the connector (2) from the ABS/ESP control unit.
• Unclip the hydraulic control unit bracket at (a).
• Lift the hydraulic control unit out upwards.

To refit, reverse the removal procedure and observe the following:

• observe the tightening torques,
• bleed the brake system,
• pump the brake pedal several times,
• check the brake fluid level,
• read and, if necessary, clear the fault memory,
• check braking efficiency and ABS operation.

Fig. 29

CONTROL UNIT

REMOVAL AND REFITTING

• Disconnect the battery.
• Set the washer fluid reservoir aside without disconnecting the hoses.
• Unlock and disconnect the connector (1) from the ABS/ESP control unit (Fig.30).
• Remove the 4 control unit mounting bolts (arrows).
• Remove the control unit from the hydraulic unit.

Fig. 30

To refit, reverse the removal procedure and observe the following:

• check the seal for damage and correct positioning; if the seal is not secured or is damaged, replace the control unit,
• do not rethread the hole in the hydraulic unit.

If the thread is damaged or the torque cannot be reached, replace the hydraulic unit,

• replace the control unit mounting bolts,
• check the brake fluid level,
• read and, if necessary, clear the fault memory,
• check braking efficiency and ABS operation.