Leak Test

WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.

Special tools and workshop equipment required

Brake Pressure Gauge :VAG1310A
Brake Pedal Actuator :VAG1869/2 .

High Pressure Test

Brake system (brake master cylinder, brake hoses, brake lines and brake calipers) tested for function and leaks.

-- Remove the bleeder screw at one of the front brake calipers. Connect the :VAG1310A and bleed.

-- Insert the :VAG1869/2 between the brake pedal and driver seat. Apply pressure to the brake pedal until the pressure gauge indicates a pressure of 50 bar (725 psi). The pressure must not drop more than 4 bar (58 psi) during the test period of 45 seconds.

Fig 1: Brake Pedal Depressor VAG 1869/2 Inserted Between Brake Pedal And Driver's Seat

Courtesy of AUDI OF AMERICA, LLC

-- Replace the brake master cylinder if the pressure decrease is too high.

Low Pressure Testing

-- 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 1.0 bar (14.5 psi) during a test period of 3 minutes.

-- Replace the brake master cylinder if the pressure decrease is too high.