Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Abs System Servicing
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 the anti-lock brake system, determine the cause of the malfunction using On-Board Diagnostics (OBD).
- When installing a new hydraulic control unit, the coding must be checked. Using the Vehicle Diagnosis Tester
- Switch ignition off before installation work. If the radio in the vehicle is coded, find out the radio code before disconnecting the battery ground cable.
- When working with brake fluid, observe relevant safety precautions and notes.
- With all work that requires hydraulic system to be opened, brake system should be bled (for example with Brake Charger/Bleeder UnitVAS5234), refer to the high and low pressure testing should also be performed on the brake system, refer to HIGH AND LOW PRESSURE TESTING
- During the final road test, perform an ABS controlled braking at least one time (pulsing must be felt in the brake pedal), using the Vehicle Diagnosis Tester
- 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 and so on.
- 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 parts that have been removed on a clean surface and cover them.
- Carefully cover or seal open components 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 parts in their original packaging.
- Do not work with compressed air and do not move vehicle while the system is open.
- Make sure that brake fluid does not enter harness connectors.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.