I have read a lot of others have the same problem I am having with the power steering fluid leak. My leak is slow, like most others I've read about. The only time I see any evidence is a sligt oil slick in my driveway after a hard rain. Have any of you tried any kind of Stop-Leak product? I know it does not sound like the perfect answer but I used a coolant stop leak in an old VW 16V GTi and it worked great, never leaked again in the last 3 years I owned the car. My concern is that it might not be compatible with the Pentosin fluid. I just e-mailed Lucas Oils to find out if their product was compatible. I will report their answer as soon as I hear but wanted to see if any of you have tried this or heard any positives or negatives about using it, or any other brands product in our cars.
2004 S4 6spd
Recently began experiencing some noise. From recent posts, I checked mine this weekend. It was low
topped it off and will see what the happens. I have 90k miles. Only problem with my b6 so far is I had to replace my starter. Will repost if the fluid is low anytime soon.
Also, I had a 98 stage 3+ B5 A4. My PS fluid leak required I added 1/4 pint every 5k miles. I didn't use any stop leak, and had no problems for about 30k miles. Later sold the vehicle. If your leak is as slow as mine was, I'd just add more fluid, and watch the level. Wouldn't gamble adding any stop leak as it may mess up functionality of the PS system. Total $5 per oil change vs aroud $1000k for a new system.
If it really is leaking out you need to find out where the leak is.
If it's say a rack seal, putting stop leak in could just mess up the pump also and cost more in the long run.
Some minor fluid loss seems to be normal on this system.
Update: Power Steering Stop-Leak -Lucas Oil's Response
Thanks for looking to Lucas for your lubrication solutions. Lucas Power
Steering Stop Leak is indeed compatible with the power steering fluid in
your Audi. It's also compatible in other lines that call for specific power
steering products such as BMW, Jaguar, Mercedes and Honda. This additive
package is very versatile.
Also, checked out Bar's Leaks and their site said it would also be compatible. The radiator stop-leak I used in my GTI was Bar's and as previously notoed it never leaked again and never had any ill affects.