After recently having my brake fluid change and a brake hose replaced on my S2, my brake pedal is now vibrating (pulsing) even when idle. This was not the case before the above work was completed. The work was carried out by my local main Audi dealer who are telling me this "NEW" fault is due to the pressure reservoir leaking & it needs replaced. The computer in car is showing the fault. Local independent Audi specialist says the pressure reservoir is linked to the ABS unit & that a new one should resolve the fault. I have had the car 3 months now and need advice. Main dealer is asking for in excess of £600 to resolve this!!!