850 GLT, Automatic, 110K

Hi Folks,

I replaced the power steering pump (see recent post), and I have a question regarding fluid compatibility. The mechanic who did the job filled the reservoir of the new unit with power steering fluid. Beforehand, the car had ATF. The blend seems to work fine, though. No noises or whines.

1. Is this mixture of ATF and PSF okay for the time being?

2. I have also read a lot about folks using Mobil 1 Synthetic ATF. If I were to do the turkey baster flush over a few days, is there any problem with mixing synthetic with the ATF/power steering fluid blend that's in there right now? ATF, PSF, and Mob1: seems like a crazy coctail to me--although maybe not as crazy as a popular drink in Spain called calimocho, a mix of Coca-Cola and red wine.

Thanks!
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1982 240 DL (265K) , 1996 850 GLT (110K)

I do not believe any harm will be done, so long as the fill level is proper. It is a hydraulic pump and requires hydraulic fluid - ATF,PSF are essentially the same. It is like adding 20W-20 to your engine oil in an emergency, it is still oil and still protects your engine.
Using the baster method does NOT remove all of the old stuff, it just helps dilute it with the new stuff. Any particulate matter will not volunteer to be extracted by the baster, you would need an inline filter for that.
Again, no harm to the PS system.

Klaus
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(V♂LV♂s 1975 164, 1995 854T, 1998 V70R)

Gracias, Klaus. My bloodpressure just went down 10 mm.
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1982 240 DL (265K) , 1996 850 GLT (110K)

If you want to go a step further, do a turkey baster flush over several days with Mobil 1 ATF then install a Magnafine filter in the PS return line. This will get virtually all stray metalic fragments in the system. It goes in the soft return line to the pump and MUST be installed with the correct flow direction as marked on the filter. WIth M1 and this filter, your chances of ever having a PS/rack problem are nil.

bl

Smart to flush it all out and add only ATF, per manual specs. Cheap, easy, doesn't take long at all, and much better for your rack and PS pump. Mobil 1 Synthetic ATF vs. dino is personal preference, but you'll get plenty of opinions. Personally, I'd be more concerened about getting one type of fluid in there than I would about what type.

Thanks for the feedback. We live in a townhouse complex where auto work has to be discrete, so do you think persistence with the turkey baster method would suffice? i.e., suck out, drive donuts around the lot or around town, and refill 4-5 times with dexron/mercon? and is it okay to refill with mobil 1 using the baster method if the system has dexron in it? Thanks.
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1982 240 DL (265K) , 1996 850 GLT (110K)

I have used Dextron in PS unit for many years. No problem. Use the baster method and take out some from top, refill, turn wheel back and forth a few time and repeat a couple of times. Not perfect for full draining, but fluid is clean.

I would not mix Mobil 1 PS and standard fluid. Probably no harm with Mobil 1 Trans fluid but see no benefit.

Now I'm really confused....you (and others) are saying that it's OK to use transmission fluid instead of power steering fluid in a PS pump?
News to me........

The manual for 850s calls for atf for power steering.
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1982 240 DL (265K) , 1996 850 GLT (110K)

Amen to Stewart's comments, and you get the old wear particles from the bad pump out of the system too.

Power steering fluid is probably the same as ATF, but may contain seal swellers to deal with minor leaks in the steering system. Probably not good for the seals, long term.

The motor oils marketed for "high-mileage" cars (since when is 75,000 high mileage?!) contain this type of additive as well.

Volvo specifies ATF for the PS system, but doesn't say what kind. I guess anything that's clean will do.