Low Pressure Testing
WARNING: This page is about a different car, the 2016 Audi A3 and 2015 Audi A3. However, it is still accessible from the selected car via links, so may be relevant.
-- Set the brake pedal actuator back far enough that the pressure gauge indicates 6 bar (87 psi) positive pressure.
-- The pressure must not drop by more than 1 bar during a test period of 3 minutes.
Replace master cylinder if pressure drops greatly.