I have a 1993 Audi 100 CS Quattro 2.8L V6 automatic transmission with 168K miles. My steering wheels started to make some squealing noise and I noticed that I need to add some power steering fluid. The reservoir says to add Hydraulic Mineral fluid. I can't find it in any local autoparts store. Searching the web I find the following two.
Pentosin CHF 7.1 and CHF 11S synthetic hydraulic fluid. SOme websites say that it is OK to mix them when ading but others say not to mix them at all. Some sites also says that 1989 and earlier VW/Audi models can use either one but the 1990 and later uses only the 11S. Is that true? How do I know if my Audi needs the 7.1 or 11S?
Call the closest Audi dealership, and inquire within. My 5000 I owned needed a special mineral oil. Goes for about 10 bucks usually. Also, if you had to "top" it off, you should be looking for leaks. This fluid is expensive, and adds up fast.
Thanks for the response mattsaudi90. I had called the dealership and they only carry the non-synthetic model and they said its good for everything. Its not a good dealership and I don't trust them. So I was looking for a second opinion here. I can call up anotehr dealer. I know where it leaked. I had jerked the power steering reservoir to replace my windshield washer tank. I must have twisted the power steering hose a little too much. But since i finished my work, the fluid has been steady but below minimum.
I am not sure where you live, but I know a reputable dealer. Yahoo search harper audi in knoxville TN, call them. They will tell you anything you want to know, with great deal of courtesy.
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Hydraulic Mineral Power Steering Fluid - 
