Hydraulic control unit, removing and installing
Special tools, testers and auxiliary items required
- Brake pedal depressor V.A.G 1869/2
Sealing plug repair kit, Part no. 1H0 698 311 A
Location:
The hydraulic control unit is installed on left-hand side of engine compartment.
Removing
CAUTION:
Brake lines must not be bent.
- Note or request radio code on vehicles with coded radio, if necessary.
- Disconnect battery. →
- 27 BATTERY, STARTER, GENERATOR, CRUISE CONTROL
- 27 - BATTERY, STARTER, GENERATOR, CRUISE CONTROL for ELECTRICAL EQUIPMENT - GENERAL INFORMATION
- Release connector from control unit in direction of - arrow - and disconnect.
- Insert brake pedal actuator V.A.G 1869/2 between brake pedal and drivers seat. Depress brake pedal at least 60 mm.
The brake pedal actuator V.A.G 1869/2 must remain in position until all brake lines have been reconnected to the hydraulic unit.
NOTE:
- Protect engine compartment against escaping brake fluid.
- Disconnect brake lines from hydraulic unit.
- Loosen securing bolt - 1 - and pull coolant expansion tank out in direction of - arrow - , then swivel tank to one side.
- Tightening torque: 6 Nm
- Seal brake lines and threaded holes with plugs from repair kit Part No. 1H0 698 311 A.
NOTE:
- Protect plenum chamber and engine compartment against escaping brake fluid.
- Remove lines - 1 - , -2- and - 3 -.
NOTE:
- On vehicles from model year 2002 a flexible hose has been installed as part of the brake lines; on vehicles built before model year 2002 the brake lines have to be disconnected at brake booster.
Fig 7: Disconnecting Brake Lines And Sealing With Sealing Plugs From Repair Kit, Part No. 1H0 698 311 A
- Disconnect brake lines - 1 - and - 2 - and seal with sealing plugs from repair kit, Part No. 1H0 698 311 A.
- Loosen connectors -1-.
- Unclip brake lines from bracket - 2 -.
- Release retaining clip from below - 1 - and pull it out in direction of - arrow -.
- Remove hydraulic control unit.
Installing
When installing, observe the following:
NOTE:
- Do not remove sealing plugs from new hydraulic control unit until corresponding brake line is to be installed.
- If sealing plugs are removed too early, brake fluid can escape, and can no longer be guaranteed that unit is sufficiently filled or adequately bled.
- Bleed brake system.
- Enter radio code.
- Connect battery. →
- 27 BATTERY, STARTER, GENERATOR, CRUISE CONTROL
- 27 - BATTERY, STARTER, GENERATOR, CRUISE CONTROL for ELECTRICAL EQUIPMENT - GENERAL INFORMATION
Tightening torques
| Component | Nm |
|---|---|
| Brake lines to hydraulic unit M10 (brake line diameter 5 mm) | 12 |
| Brake lines to hydraulic unit M12 (brake line diameter 5 mm) | 12 |
| Brake lines to hydraulic unit M12 (brake line diameter 8 mm) | 20 |