I have 02 A6, yesterday when I stepped on the brakes I heard what sounded like a gurgling sound behind the dash and the brakes stopped working they way they should. I still have brakes, no loss of fluid, but I have to just about stand on the pedal to stop. Haven't had a chance to call the service tech and it is about 50 miles one way to get there, am I still safe to drive short distances and what could be the problem?