Hydraulic Control Unit, Removing and Installing

Hydraulic control unit, removing and installing

Special tools and equipment
Plug repair set, Part no. 1 HO 698 311A
Brake pedal depressor, e.g. from V.A.G 1813





Installation location
The hydraulic control unit is installed on left side of engine compartment.

Removing

CAUTION: Brake lines must not be bent.

- For vehicles equipped with coded anti-theft radio, note radio code, obtain if necessary.
See Caution before beginning repairs on the electrical system
- Disconnect battery.





- Unlatch connector from control module in direction of -arrow- and unplug.
- Insert brake pedal depressor between brake pedal and driver's seat. Depress the brake pedal by at least 60 mm.

Note:
^ The brake pedal depressor must remain in position until all the brake lines have been reconnected to the hydraulic unit.
^ Protect the engine compartment against escaping brake fluid.

- Unscrew brake line connections on hydraulic unit.





- Remove bolt -1- and pull it out in the direction of the arrow, and swing the coolant expansion tank to side.
- Tightening torque 6 Nm
- Seal brake lines and threaded holes with plugs from repair kit Part No. 1H0698311 A

Note: Protect the plenum chamber and the engine compartment against any escaping brake fluid.

- Unscrew and remove lines -1---2- and -3-.





- Detach brake lines -1- and -2- and seal with the dummy plug from repair kit Part No. 1 HO 698 311 A





- Detach connectors -1-.
- Unclip brake lines -2- from bracket.
- Release the locking clip from below -1- and pull it out in the direction of the arrow.
- Remove hydraulic control unit.

Installing
When installing, pay particular attention to the following points:

Note:
^ Only remove sealing plugs on new hydraulic control unit when the corresponding brake line is about to be installed.
^ Brake fluid can escape, if the sealing plugs are removed too early, it can no longer be guaranteed that the unit is sufficiently filled or adequately bled.

- Bleeding brake system ESP 5.3 or ESP 5.7.
- Enter radio code.
See Caution for connecting Telematics battery
- Connect battery ground strap.