Wondering if anyone has experienced this issue...basically there is a slight hissing noise coming from the brake pedal area but when I depress the pedal it stops. I discovered it last year some time (when radio & air-con were switched off) and initially it worried the hell out of me, but I don't believe there is anything amiss with braking performance. I had it checked out at APS in Brackley when it was last serviced but they weren't able to identify any fault (they did mention something about a valve that may be the cause?).
Have trawled the net searching for the same issue and it seems other VWs & Audis have had the same symptoms but there's no definitive solution. Is it worth going back to the stealers to get it looked at while still under warranty or will they just rip me off? :-O
(2009 Audi S3 Sportback)