-- [ Picked text/plain from multipart/alternative ] Your Master Cylinder is going bad. The return circuit is not working and keeping fluid pressure on your calipers. I replaced my Master Cylinder on my 5000 TQ with a new one for an S4. The old P/N for the 5000/200 supersedes to the newer type Master Cylinder for the S4. JIM ///Audi5TurboTech