Swap power steering fluid to CHF 11s

[ChipperM3]

I'm going to do a power steering flush with a new reservoir and hoses. If I'm flushing the system anyway, I was thinking about swapping from ATF to CHF 11s. The info on this is little tougher to find with the old forum down, but I think Obioban did this. I'm pretty sure there is no compatibility issues with the system in our cars from my research, but if anyone with any info that might be relevant would chime in (Obioban?), that would be great.

[Obioban]

I did do this. I don't recommend it. The CHF-11S seem to boil much more easily as my first track event it boiled over, out of the power steering reservoir. In retrospect, I probably should have known-- boiling power steering fluid is a normal issue on the e9X M3 (which uses CHF-11S stock).

Swapping over was a mistake. A nice synthetic ATF (e.g. M1) works great and is problem free.

If you do do it, know that it isn't compatible with the stock fluid-- so you need to drain all components of the system and then do a couple flushes with CHF-11S to get all ATF out of the system.

[ChipperM3]

Perfect! Thanks for the quick response. That settles that; I’ll stick with ATF.

[Feffman]

Perfect! Thanks for the quick response. That settles that; I’ll stick with ATF.

I run Mobil-1 ATF in the race car power steering, and (knock on wood) I've no issues.

Feff

[mrgizmo04]

That said, if you are not setting lap records at the track, you will be fine with CHF - 11S. I swapped over when I did a full refresh of rack/hoses/reservoir and have had no issues.