Repair Information

ABS System, Repair Information

CAUTION:
^ The anti-lock brake system is basically maintenance-free.
^ Testing, installation and repair work must always be carried out by properly trained technicians.
^ Non-compliance with the information may result in damage to the system and could make the vehicle unsafe to drive.
^ Absolute cleanliness is required when working on the anti-lock brake system. Do not use any products which contain mineral oil, such as oils, greases etc.
^ Thoroughly clean all unions and the adjacent areas before loosening. Do not use aggressive cleaning agents such as brake cleaner fuel, thinners or similar chemicals.
^ Place removed components on a clean surface and cover.
^ Carefully cover or seal open parts if repairs cannot be carried out immediately (use sealing plugs from repair kit 1HO 698 311 A). Part numbers are listed here for reference only.
^ Do not use fluffy cloths.
^ Only remove replacement parts from packaging immediately prior to installation.
^ When the system is open do not work with compressed air and do not move the vehicle.
^ Make sure that brake fluid does not enter the harness connectors.
^ During painting operations, the electronic control unit can be exposed to a max. temperature of 95°C (203°F) for only a short period, and to a maximum of 85°C (185°F) for longer periods (approx. 2 hours).
^ Before carrying out welding work with an electric welding unit, refer to safety precautions.

Notes
^ When working with brake fluid, observe the relevant safety precautions and notes. Refer to Brake Bleeding.
^ After finishing any work that required opening the brake hydraulic system, bleed the brake system (e.g. using VAG1869).
^ Use only packaged genuine Audi replacement parts.
^ During the final road test, at least one ABS-controlled braking operation must be performed (normal pulsations must be felt at the brake pedal).
^ Before carrying out repairs to the ABS, determine the cause of the malfunction using On Board Diagnostic (OBD).
^ Always check the control module coding when installing a new hydraulic control unit.
^ Always switch the ignition off and disconnect the battery Ground (GND) strap before carrying out installation or repair work.

CAUTION: Before disconnecting the battery, determine the correct coding for the anti-theft radio.