ATF in the power steering fluid

I was picking up some power steering fluid at the dealer, and the service guy mentioned putting in "some" Dexron VI if the pump is noisy to quiet it down.

Both PSF and ATF are hydraulic fluids, so I can see this as plausible, I was just wondering if any of you guys had heard of this or done it in our cars.

I know this was common practice way way back, when power steering was in it's infancy. Now with all the additives etc., it's probably not a good idea; but then again it maybe OK.

Tom

NO. If the system is designed for PSF, use that. ATF will foam up and possibly damage seals.

Does this "service guy" actually work on cars there, or was he the service writer? I'd avoid that place altogether for that kind of suggestion.

Not to say I've not done dumb things. I didn't do my research and just filled up the PS system with ATF when I finished the LS swap on my C10. Had no PS when I first started it up. Now, I couldn't tell you if it was my fault for not putting the pump back together right after the swap, or the ATF, but that pump blew apart in the casing. Had to hammer the reservoir back into shape and just swapped in the original pump from my truck. Likely my fault for crappy re-assembly. But I did have to flush the system and put in PSF. So yea if you do that, and get foaming, you'll have to flush the whole system. Additives are just a bandaid for leaky hoses and oil seals and never really fix the real problem.

I have run straight 30 weight in the PS pump. Did it for months until I fixed the leak (it leaked a little slower as the 30 weight was thicker). Was told to do so by Larry Lype (RIP) wagon master extraordinaire and former NASCAR driver/mechanic.

It firmed up the steering a bit too.

Interesting. I don't think I'd do it, I was more curious if anyone could confirm that some ATF in the system would quiet down the pump. The PS pumps in these cars are pretty noisy in general.

I know some cars use ATF for their PS systems too. I think that's what prompted the service guy and parts guy to talk about it.

30W in the PS is interesting, I never heard of that before

Most Mack trucks use 10w40 for their power steering. Most everything else uses ATF.

As for my cars, I've always put ATF in the reservoir. Did a partial "Turkey Baster" flush on my old 94 using ATF.

I have added a little atf to noisy ps pumps for years. Sometimes it helps. Have never seen it cause a problem

Atf always for me,. Or i borrow some aw32 from the neighbour,.

phantom 309 wrote:

Atf always for me,. Or i borrow some aw32 from the neighbour,.

That makes sense, ATF is closer to orange than PSF

AW32 is straight hydraulic fluid if my searching is accurate. I don't see why that wouldn't work either.

Ive run aw32, dexIII, used dexIII, MVatf, merconV, and the correct fluid in the OCC over the years. Ive finally gotten around to getting new hoses for the pump. Pump is none the worse for it all, I don't think the old Saginaw cares as long as it has something in it.

But not motor oil. Old rubber gets really soft in a big hurry with motor oil, and I wouldn't use that unless I had a long term plan to swap out everything in the near future.