Hydraulic System: Testing and Inspection

Test Requirement
Function of conventional braking system (master cylinder, brake hoses and lines, and brake calipers) OK

Checking High Pressure
1. Remove bleeder screw from one front brake caliper.





2. Connect and bleed pressure gauge VAG1310, or equivalent
3. Install brake pedal depressor between brake pedal and driver's seat, and load brake pedal until pressure gauge indicates 50 bar (725 psi).
4. Monitor pressure for 45 seconds.
- Pressure must not drop more than 4 bar (58 psi)
5. If the pressure drop is greater, replace the ABS hydraulic unit.

Checking Low Pressure
1. Adjust brake pedal depressor until pressure gauge indicates 6 bar (87 psi).
2. Monitor pressure for 3 minutes.
- Pressure must not drop more than 1 bar (14.5 psi).
3. If the pressure drop is greater, replace the ABS hydraulic unit.