I've been mulling this over in my head for a while, and wondered what you guys would think about this subject.
I've read some comments that using modern ATF in the power steering system of our old Mercedes is not recommended, it doesn't play well with the seals. What about using a mineral oil? I'm stocked up on
Pentosin CHF 7.1 and am pondering using this in my SDL's power steering. CHF 7.1 is very similar to (if not the same as?) the old mineral oil SLS fluid. My Audi uses this for the power steering and brake assist, and both of my Jetta ECOdiesels had this from the factory in the steering.
I've also got
CHF 11S on hand. This is what virtually every modern German car used in their power steering systems. It's a very fancy synthetic fluid, and thus costs $10 more per liter then the old 7.1 fluid. I think I'll save my stockpile of 11S for my TDI
I've got generic clear "Power Steering" fluid in my SDL now, and am not 100% happy with its performance. It's possible to use up all of the pump's pressure doing quick wheel turns at low engine speeds. I don't recall the car doing this when I initially had it, but flushing out the old ATF in the system was one if the first things I did so I may not be remembering correctly.
-Jason