Hydraulic Control Unit and Bracket, Removing and Installing

Required special tools and operating instructions





^ VAG1331 torque wrench





^ VAG1869 Brake filling and bleeding tool





^ VAG1869/2 Brake pedal depressor

Removing
- For vehicles with coded radio, note code; ask if necessary.
- Disconnect battery.





- Depress brake pedal and keep down using brake pedal depressor VAG1 869/2.





- Remove connector - 1 -for air mass sensor.
- Unscrew bolts - 2 - on air filter housing - 3 -and place housing to the left side.





- Place absorbent towel under the hydraulic unit in order to collect brake fluid.

Notes: Brake lines in area of hydraulic unit must not be bent.

- Unscrew brake lines from brake master cylinder to hydraulic unit (arrows), and protect against dirt with caps from repair set 1 HO 698 311 A.





- On vehicles with left hand drive, tie up disconnected brake lines with wire, so that brake line ends are higher than brake fluid level in reservoir.
- Unscrew remaining brake lines from hydraulic unit.





- Plug the hydraulic line connections at the hydraulic unit with plugs - 1 -from repair set 1 HO 698 311 A.

Notes: During the following work step (and in general) make sure that no brake fluid enters the housing of the control module. This can lead to corrosion of contacts and result in system failure. If there is dirt in connector housing, clean carefully with compressed air. Connections to the hydraulic unit must be protected with plugs from repair set 1H0 698 311 A.





- Loosen multi-pin connector and remove from control module.





- Unscrew bolts at bracket for hydraulic unit.
- Remove hydraulic control unit.

Installing

Notes:
^ Only remove plugs at hydraulic unit when the corresponding brake line is about to be installed.
^ If plugs are removed from hydraulic unit any earlier, brake fluid can flow out, so it may no longer be possible to fill and bleed the unit properly.

- Install hydraulic control unit in reverse order.
- Bleed brake system.