I have an Audi 80 Sport 2.0 1995. In February I noticed a hissing sound tranlating itself through the dash and the steering column. The hiss would not appear at first but would gradually get louder as the car warmed up. The hiss only occurs when the steering is not being turned (either left or right) and when returning the steering from lock back to a central position. I contacted audi who took a look and said the steering rack was at fault. Audi's price for a replacement was ridiculous so I purchased a rack elsewhere and had it fitted. The problem was still present. Next I was told it was the pump so after saving some money I purchased a new pump. Before I could fit the pump the steering failed and so I got to work presuming the pump had failed and promptly fitted the new one. The steering failed again and dumped all of the hydraulic fluid into the footwell behind the pedals. The rack and pump were sent off to be tested (4 Weeks!!!!) and it was found that the pump was fine and after the repair on the seal of the rack was carried out that this was also ok. However I still have the same problem that occurred 7 months ago. Can anyone give me a clue as to the origins of this hissing noise? Everytime I ask for advice and help from mechanics they scratch their heads like Stan Laurel and the whole thing is turning into a farce as well as costing me more money.