ABS Hydraulic Control Unit, Removing and Installing

ABS hydraulic control unit, removing and installing

Special tools and equipment





^ VAG 1331 Torque wrench
^ VAG 1410 Torque wrench
^ VAG 1869/2 Brake pedal depressor
^ VAG 1 551 Scan Tool (ST)





Sealing plugs, repair kit Part No. 1 H0 698 311A
Installation location
The hydraulic control unit is installed on the left side of the engine compartment.

Removing

CAUTION: Do not bend brake lines.

- 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.





- Disengage connector from control module (arrow -1-) and disconnect (arrow -2-).
- Connect bleeder bottle to bleeder screw on left-front brake caliper and open the bleeder screw.
- Insert brake pedal depressor between brake pedal and driver's seat. Depress the brake pedal by at least 60 mm.

Note:
Do not remove brake pedal depressor until all brake lines have been reconnected to the hydraulic control unit.

- Close left-front bleeder screw.

Note: Cover engine compartment to make sure that brake fluid does not flow into it.

- Disconnect brake line connections at hydraulic control unit.
- Seal brake lines and threaded holes with plugs from repair kit Part No. 1 HO 698 311 A.
- Remove hex nuts on hydraulic control unit bracket.
- Remove hydraulic control unit.
When installing, pay particular attention to the following on points

Note:
^ Only remove sealing plugs on new hydraulic control unit when the corresponding brake line is about to be installed.
^ If the sealing plugs are removed too early, brake fluid can escape. If this occurs, the unit may not be sufficiently filled or adequately bled.
- Enter radio code.
See Caution for connecting Telematics battery