Control Module and Hydraulic Unit, Removing and Installing

Control module and hydraulic unit, removing and installing

Special tools, testers and auxiliary items required
^ Torque wrench V.A.G1331
^ Torque wrench V.A.G1410
^ Brake pedal depressor V.A.G1869/2 or equivalent

Removing
Location:

The control module is bolted to the hydraulic unit and is in the engine compartment on the left side.

CAUTION: Do not bend the brake lines in the area of the hydraulic unit!

- Obtain radio code on vehicles with coded radio.
- Disconnect battery.

- Disconnect intake hose - 1 - and connectors - 2 - from the Mass Air Flow (MAF) Sensor.
- Remove bolts - 3 - , - 4 - and - 5-.
- Remove air cleaner completely.

- If installed, remove relay protective housing -1- from cable channel.
- Draw off as much brake fluid as possible from brake fluid reservoir using a suction bottle.

Observe safety precautions

- Release connector from control module - arrow 1 - and pull it off - arrow 2-.
- Install brake depressor V.A.G1869/2.
- Connect a bleeder bottle hose to left front and right rear brake caliper bleeder screws and open bleeder screws.
- Depress brake pedal at least 60 mm using brake pedal depressor.
- Close left front and right rear bleeder screws
- Do not remove brake pedal depressor V.A.G1869/2.
- Place sufficient lint-free cloths under control module and the hydraulic unit.

CAUTION: Make sure no brake fluid reaches the contacts.

- Disconnect brake line from ABS hydraulic unit - 1 - to the brake master cylinder and tie-up.
- Disconnect the remaining brake lines from the ABS hydraulic unit N55.
- Seal brake lines and threaded holes with sealing plugs from Repair kit 1 H0 698 311 A.
- Remove bolts - arrows - from bracket for control unit/hydraulic unit.
- Remove ABS hydraulic unit N55 with ABS control module J104.

Removing ABS control module from hydraulic unit
- Place hydraulic unit with control module downward on a clean flat surface.

- Remove Torx(R) socket head bolts E5 - arrows - from ABS control module J104 and pull off ABS control module.

CAUTION: The hydraulic pump may not be separated from the hydraulic unit.

- Carefully lift the hydraulic unit along with the hydraulic pump, at the joint - 1 - -, upward off the control module.

When pulling off of the control module, make sure that the hydraulic unit electrical contact pin - 2 - is not tilted against the control module solenoid valves.

Cover control module magnetic coils with a lint-free cloth.

After separating control module and hydraulic unit use transportation protection device for contact pin.

The electrical contact pin supplied as a spare part for the control module can only be clipped in once and thereafter never removed again.

Installing

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

When assembling the control module to the hydraulic unit, make sure that the hydraulic unit electrical contact pin is not tilted against the control module solenoid valves.
- Using new bolts, install control module to hydraulic unit. Observe maximum tightening torque of 4 Nm 4 Nm
- Bolt ABS control module to bracket.
Do not tighten bolts completely. Attaching the individual brake lines is made easier.
- After tightening brake lines, tighten hydraulic unit.
- Installation is carried out in reverse sequence.
- Remove brake pedal depressor V.A.G1869/2.
- Bleed brake system.
- Enter radio code..
- Code control module.

Torque settings: