Removal and Replacement

Control Module and Hydraulic Unit, Removing and Installing

Special tools, testers and auxiliary items required





^ Brake pedal handle V.A.G. 1869/2





1 - Valve dome transportation protection (plastic foam)

2 - M 10 sealing plugs for brake lines and threaded holes

3 - M 12 sealing plugs for brake lines and threaded holes

After separating the control module from the hydraulic unit always install the valve dome transportation protection on the hydraulic unit.

Warranty claims for hydraulic units on which the valve dome transportation protection was not used, will not be accepted.

Removing





- Remove screws - arrows -.
- Remove forward left-hand cover panel.





- If installed, disconnect secondary air intake hose -1- from air cleaner.
- Disconnect air hose -2- from mass air flow sensor.
- Unplug connector -3- from mass air flow sensor.
- Unscrew bolts -4- and -5-.
- Remove air cleaner housing.





- Insert Brake pedal handle V.A.G. 1869/2 between brake pedal and drivers seat. Depress the brake pedal by at least 60 mm.
- Connect hose of bleeder bottle to bleeder screws on left front and left rear brake calipers and open bleeder screws.

Note:
^ This dissipates pressure in hydraulic unit.

- Close left front and left rear bleeder screws.
- Do not remove Brake pedal handle V.A.G. 1869/2.





- Release control module connector - arrow 1 - and unplug - arrow 2 -.

Note:
^ Protect connector housing of control module against escaping brake fluid. Otherwise corroding contacts can cause a breakdown of the system.
^ Carefully clean a moist or dirty connector housing with compressed air.

- Lay out sufficient lint-free cloths in area below control module and hydraulic unit.
- Mark brake lines.





- Disconnect brake lines -1- from hydraulic unit to brake master cylinder and tie up.
- Disconnect remaining brake lines from hydraulic unit.

CAUTION
Take care not to bend brake lines in the vicinity of the hydraulic unit.

- Seal brake lines and threaded holes with plugs from repair set.
- Unscrew bolts at hydraulic unit - arrows - and take out hydraulic unit and control module.

Control Module from Hydraulic Unit, Removing

- Place hydraulic unit with control module down on a clean flat surface.





- Remove Torx socket head bolts - arrows -.

CAUTION
The hydraulic pump must not be separated from the hydraulic unit.

- Separate hydraulic unit with hydraulic pump from control module by lifting carefully off joint -1-.





- When detaching control module, make sure valve domes of hydraulic unit do not catch on control module solenoids.
- Cover control unit solenoids with a lint free cloth.
- Protect components against moisture.
- Install transportation protection for valve domes (enclosed in repair kit) after separating control module and hydraulic unit.

Note:
^ The valve dome -2- supplied as spare part with the control module can only be clipped in once. It is not possible to separate the connection afterward.

Installing

Install in reverse sequence; note the following points:

Note:
^ Only remove sealing plugs on new hydraulic unit when the corresponding brake line is going to be installed.
^ If the sealing plugs are removed too soon from the hydraulic unit, brake fluid may escape, it may no longer be possible to fill and bleed the unit properly.

- When assembling control module and hydraulic unit, make sure valve domes of hydraulic unit do not catch on control module solenoids.
- Connect lines as previously marked.
- Bolt ABS module to bracket.

Note:
^ Do not fully tighten bolts. This facilitates attachment of individual brake lines to hydraulic unit.

- After tightening brake lines, tighten hydraulic unit.
- Bleed brake system.
- If a new control module has been installed it must be coded.
- After connecting brake lines to hydraulic unit, perform final control diagnosis.

Note:
^ Final control diagnosis can be used to establish whether line connections have been interchanged.

Tightening Specification