ATF in PS Reservoir

Gee, that was dumb.

If you managed to realize your goof before you turned it over, and you were able to get a suction gun down to the bottom of the reservoir shell, you might have done OK. The best way to do this is to simply take the return hose off the reservoir, plugging the hose barb on same to prevent more fluid loss, start the engine while the exhaust fluid goes into a pan below while you add PS fluid to the pump through a funnel.

Is your PS fluid pink now? If so, do the above.

Contrary to DesertBob's claim, you haven't got a disaster situation on your hands. ATF is not all that different to the P/S fluid specified for that system. P/S fluid is preferable, but Mercon V is a high-test ATF, and a *quarter cup* of it will have no ill effect on the system even if you hadn't made the effort to remove it. Quit worrying, drive and enjoy.

Good, then you can pay for a new top seal for him when it starts to leak. PS fluid, while having similar properties to ATF in many regards, is exposed to much higher pressures than is ATF in a transmission application. Some high pressure/high heat episodes, and breakdown may start to happen. My understanding of Chrysler's PS spec is a specific addition of anti-oxidation and anti-corrosion additives not found in conventional ATFs.

What he did to rectify the error is probably as good as is necessary.

A quick look in the parts book will show that many of the internal seals have gone unchanged since the sixties when ATF was the factory recommended fluid. ATF also has anti-oxidants and corrosion inhibitors; the only noticeable difference in the two (besides color) is the anti-foaming properties and this only becomes an issue when the steering is deflected against the stop in either direction.

No big deal. No problem. No sweat. Quick lubes have done a lot more harmful things than that. But if it is leaking much you need to be looking for the leak. MT

The problem isn't the ATF, the problem is to mix this two different fluids, especially to deteriorate the foaming properties to prevent cavitation damage.

Regards,

Ralf

My 04 TJ came with ATF+4 in the PS unit Where my wifes 04 WJ with the same engine uses typical PS fluid go figure.

Coasty

Let's keep it real, here, folks. These predictions of catastrophic failure and blathering about inapplicable degradation of anti-foam properties is just way off base. We're talking about 2 fluidounces of a fluid extremely similar to the specified fluid, added to a system containing mostly the specified fluid, and subsequently mostly removed.

...is lacking, as it seems.

Millions of people use ATF in power steering units all the time. It's not at all unusual.

ROTFL! Higher pressures in a PS system than an AT. Gotta love the lunacy.

Some high pressure/high heat episodes, and

Care to bet your house on that?

P/S test pressure routinely tops 1500 psi while the AT seldom exceeds 300 psi. Irrelevant to this discussion since both fluids can handle either pressure range.

Thanks. Now, about that trust deed to your house, Steve....

Common ATFs in the past, like Types A and F, would carbonize easily under the pressures NORMALLY associated with power steering application. That's why, in the '60s, Ford routinely used coolers on their PS pump return lines to try to reduce carbonization, which back then, was a real problem. I've pulled apart and redone enough PS pumps in my time to have seen it...the shell full of carbonized chunks and goo, and the whining, jerking operation of the PS box and/or control valve. With more modern fluids, I'd think there may be less to worry about, but back then, it was a real problem, as was foaming. Anyone who ever worked on a Saginaw rack-and-gear system (1951-55) knows that all too well!

The offroad industry uses ATF in hydrostatic units which have relief valves set at 5500 psi...quite abit higher than an automotive PS