One problem related to power assist brake hoses, lines/piping, and fittings has been reported for the 1999 Audi A4. The most recently reported issues are listed below.
The contact owns a 1999 Audi A4. When applying the brakes at any speeds, the vehicle slows down but does not stop as it should. The contact has had to depress the brake pedal with both feet in order to stop the vehicle. The failure occurs intermittently. The dealer stated that the VIN was not included in NHTSA campaign id number 99v131001 (service brakes, hydraulic:power assist:vacuum:hoses, lines/piping, and fittings). The current mileage was 110,000 and failure mileage was 95,000. Updated 6/16/08.