I bought a 1997 Audi A4 with a 1.8L (no turbo) engine about a week ago and started having power steering problems soon after. I borrowed the car to a friend for a day and when I got it back the power steering was no more, I checked the fluid reservoir and the fluid was low, so I went and got the green Audi PS oil and topped it up according to instructions from the owner's manual, but at idle the power steering didn't work even then. When I gave it a little gas it started working, but then the oil came out of the pump. It was being thrown all over the engine room, so I figured it had to be the shaft seal leaking it onto the pulley.

Today however I finally got the pump out and out of curiosity, I started opening it up to see what's inside. I found nothing visibly wrong with it. I broke it up into pieces and everything looked fine, even the shaft seal looks intact to me. I can't feel any play in the shaft in any direction.

So, what's wrong? Initially, not really knowing what type of pump it is or anything (now I know it's rotary-vane pump ), I figured it could be sucking in air at idle through the shaft seal and keeping it from building pressure, then at higher RPM it would generate pressure and blow it out through the seal. But the seal looks fine. Could it still leak? According to the stampings the pump seems original.

Anyway, I don't think there's a rebuild kit for the pump so I'll end up buying a new pump in any case, but this is still bugging me and I'd like some thoughts on what could be wrong.

 

I went ahead and exchanged my old pump for a rebuilt one today, even though I wasn't really able to find anything visibly wrong with the old pump. When I was installing the new pump, I started thinking to myself if it could have been the banjo joint on the pressure line leaking? Although I think I would have noticed that, I don't think the joint was wet or anything... And I remember the bolt being rather tight when I was opening it up, it shouldn't start leaking if the bolt doesn't come loose right? Then again the shaft seal looked intact as well... Would be kind of embarrassing to miss a leaking banjo joint and replace the whole pump And anyway, too late to worry, new pump's already in.

Also another thing I noticed after I got the pulleys onto the new pump, was that the water pump pulleys were out of alignment with eachother a bit, not by much, maybe a millimeter or so. Is this something to worry about? The new pump was physically the same size as the old one anyway. The main belt pulley is aligned with the others (measured with a straight edge), so I guess the water pump pulleys have always been out of alignment?