ABS General Information

ABS General Information

CAUTION!
The anti-lock brake system is generally maintenance-free.

Testing, assembly, and repair work may only be performed by qualified personnel.

By not observing the points described in the repair manual, the system can be damaged and vehicle safety could be compromised.

• Before performing repair work on Anti-lock brake system, determine cause of the malfunction using On-Board Diagnostics (OBD).

• If you install a new hydraulic control unit, you must check its coding.=> VAS 5051 Vehicle Diagnostic, Testing and Information System

• Switch ignition off before installation work. On vehicles with coded radio, determine code and disconnect battery Ground (GND) strap.

• When working with brake fluid, observe relevant safety precautions and notes => [ Brake Fluid ] Description and Operation.

• With all work that requires hydraulic system to be opened, brake system should be bled (e.g. with Brake Filler/Bleeder Unit (VAS 5234))=> [ Electronic Stabilization Program Brakes, Bleeding ] Electronic Stabilization Program Brakes, Bleeding. High and low pressure testing should also be performed on the brake system => [ Pressure Leak Test ] Pressure Leak Test

• During final road test, ensure that an ABS controlled braking is performed at least one time (pulsing must be felt in brake pedal). See => Vehicle Diagnosis, Testing and Information System (VAS 5051)

• Absolute cleanliness is required when working on the Anti-lock brake system, it is not permitted to use any products which contain mineral oil, such as oils, greases etc.

• Thoroughly clean all unions and adjacent areas before loosening. Do not use aggressive cleaning agents such as brake cleaner, fuel, thinners or similar chemicals.

• Place parts that have been removed on a clean surface and cover.

• Carefully cover over opened components or seals, if repairs are not carried out immediately. (Sealing plugs, use repair kit 1 H0 698 311 A)

• Only use lint-free cloths.

• Only unpack replacement parts immediately prior to installation.

• Only use genuine packed parts.

• Do not work with compressed air and do not move vehicle while system is open.

• Make sure that no brake fluid enters plug connectors.