Audi Workshop Service and Repair Manuals

Special tools and workshop equipment required

→ Fitting location

The hydraulic control unit is fitted on the left side of the engine compartment.

Removing

• ‒ Note radio code on vehicles with coded radio; if necessary ask for it.
• ‒ Disconnect battery.

=> Electrical System; Repair group 27; Battery

• ‒ → Release connector from control unit (arrow -1-) and unplug it (arrow -2-).
• ‒ Connect bleeder bottle to bleeder screw on front left 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.

The brake pedal depressor must remain in position until all the brake pipes have been reconnected to the hydraulic unit.

• ‒ Close front left bleeder screw.

• ◆ Protect the engine compartment against escaping brake fluid.

• ‒ Unscrew brake pipe connections on hydraulic unit.

• ‒ Seal brake pipes and threaded holes with plugs from repair set Part No. 1H0 698 311 A.
• ‒ Remove hexagon nuts on hydraulic control unit bracket.
• ‒ Remove hydraulic control unit.

Pay special attention to the following on installation:

• ◆ Only remove sealing plugs on new hydraulic control unit when the corresponding brake pipe is about to be fitted.
• ◆ If the sealing plugs are removed too early, brake fluid can escape, it can then no longer be guaranteed that the unit is sufficiently filled or adequately bled.

• ‒ Bleeding brake system
• ‒ Enter radio code.