Brake Proportioning/Combination Valve: Description and Operation

Brake Pressure Regulator:

Brake pressure regulator -(A)- is mounted beneath brake booster and supplies reduced braking pressure to rear axle.

Only in conjunction with full-time all wheel drive system, 4000 Quattro braking circuits are divided between front and rear axle instead of diagonal circuits as on other Audi front wheel drive only vehicles.

In the event of pressure loss to front axle brakes, full rear circuit braking pressure os supplied.

Brake pressure regulator is not adjustable.