High-Pressure and Low-Pressure Leak Test

Requirement
- The conventional brake system (brake master cylinder, brake hoses, brake lines and brake calipers) are in proper order and free of leaks.

High-pressure test





- Remove breeder screw affront brake caliper. Connect pressure gauge VAG131 0 or VAG131 OA and bleed.
- Insert brake pedal depressor between brake pedal and driver's seat. Apply pressure to brake pedal until gauge indicates pressure of 50 bar (725 psi).
- Pressure must not drop by more than 4 bar (58 psi) during the test period of 45 seconds.
- If pressure drop is greater, replace ABS hydraulic unit.

Low-pressure test
- Turn back brake pedal depressor until pressure gauge indicates system pressure of 6 bar (87 psi).
- Pressure must not drop by more than 1 bar (14 psi) during test period of 3 minutes.
- If pressure drop is greater, replace ABS hydraulic unit 1