High-Pressure and Low-Pressure Tests

High-pressure and low-pressure tests
Before beginning
Check brake system (master cylinder, brake hoses, brake lines and brake calipers) for function and proper sealing (must be free of leaks).

High-pressure test





- Remove bleeder screw at one front brake caliper. Connect VAG131 0 or VAG131Oa brake pressure gauge and bleed.
- Insert brake pedal depressor between brake pedal and driver's seat. Apply pressure to brake pedal until gauge indicates positive pressure of 50 bar (725 psi). Pressure must not drop by more than 4 bar (58 psi) during test period of 45 seconds. If drop in pressure exceeds specification: replace hydraulic control unit.

Low-pressure test
- Move brake pedal depressor back until pressure gauge indicates pressure of 6 bar (87 psi).
^ Pressure must not drop by more than 1 bar (14.5 psi) during test period of 3 minutes.
If drop in pressure exceeds specification: replace hydraulic control unit.