My car’s manual specifies Pentosin CHF 11S power steering fluid, which I’m having a hard time finding. The web suggests that there are many compatible (and many incompatible) fluids out there, but aside from the occasional proprietary part number, the web hasn’t been terribly useful. It also doesn’t help that it’s Sunday, as I can only get telephone guidance from Pepboys and the like.
So: What can I put in the car without worry? I don’t need cold weather performance or anything, just plain old P/S fluid that won’t cause any problems.
I don’t know whether or not there are any safe substitutes for CHF 11S. I do know that in some cars, using the wrong type of fluid will damage seals and result in significant leakage (along with significant repair bills to fix it). Using non-Honda type fluid in Honda and Acura cars will do this. Apparently using non-CHF 11S in cars that require it will do it as well (see here, 3rd post down). Unless you get an authoritative answer from someone who clearly knows what he’s talking about, as opposed to someone who doesn’t realize the difference and blithely assumes that because he’s never heard of the problem it doesn’t exist, I think you’d be wise to keep strictly to the CHF 11S.
Auto parts stores that cater to professionals (Carquest, NAPA, etc.) and various European car dealerships stock the CHF 11S.