Is there a difference between P/S fluid and ATF?

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Just wondering if there's any harm in using P/S fluid in place of a system that calls for ATF and vice versa? I went to have my Tacoma P/S system flushed at a Mobil Lube Express but stopped them because they were going to use P/S fluid over the Dex III ATF it calls for, was I wrong to do this?
 
That's what I would've done. I always go by the book. I'm not saying what they were going to do wouldn't have worked, but you were paying them to do the job right which is by the book.
 
Originally Posted by TheLawnRanger
That's what I would've done. I always go by the book. I'm not saying what they were going to do wouldn't have worked, but you were paying them to do the job right which is by the book.



+1
 
I have been using Redline synthetic power steering fluid in my 02 Camry for 5 years now without issue
 
Some applications are pickier than others. The G37 calls for Nissan/Infiniti PSF, Matic J (and then Matic S subsequent), or Dexron (on the cap), or Dexron-VI (yes, by name) as the strong preference in the manual. Pentosin claims their CHF works, too. So, clearly some systems aren't terribly picky. I'm sure most of the other PSF options on the market would do fine. Now, if it were a Honda or a German vehicle, I'd probably be looking for the Honda fluid and its clones, or Pentosin CHF and the equivalents, respectively.
 
Most applications I use ATF not PS fluid. It is just easier to by one fluid. Check your applicable owners forum. You will likely get answers you are seeking.
 
It depends.

Application specific Power Steering fluids do not have the proper base oil mix or additive package and should not be used in an AT.


There are vehicle manufactures that allow ATF to be used in power steering systems but in no way would I allow any fluid marked "PSF" to be used in an AT.
 
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Toyota specs Dexron II or III (which is no longer a licensed spec) for PSF, but from what I've read, most dealerships just use regular PSF for services. I'm currently using Valvoline Maxlife ATF in my 07 Tacoma. Before I started using Maxlife, I used Mobil 1 Synthetic ATF. These trucks aren't picky about PSF.
 
Originally Posted by MolaKule
There are vehicle manufactures that allow ATF to be used in power steering systems but in no way would I allow any fluid marked "PSF" to be used in an AT.

I think that's very important. We always talk about using ATF in a power steering system, and most of us know the reverse isn't a good idea, but it should be pointed out here to not try it to those who aren't up on that.
 
Both my Jeeps call for ATF+4 in the PS pump, that's what they get. My E-150 calls for Type F fluid in the PS pump, that's what I use. I'm sure PS fluid would work, but it is just as easy for me to use the ATF they call for. I always have it on hand too.
 
My Jeep requires PSF and I have heard that going to ATF can cause a whine. Not sure, but not willing to find out either.

My truck can take either or, but currently has PSF since that's what I had on hand in the gallon form when I was reassembling the system last summer after some front end work. The same fluid in the transmission and power steering would be the way to go IMO, but oh well.

ATF will be a tad thinner if that matters. (Maxlife vs. Valvoline PSF)
 
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Originally Posted by demarpaint
Both my Jeeps call for ATF+4 in the PS pump, that's what they get. My E-150 calls for Type F fluid in the PS pump, that's what I use. I'm sure PS fluid would work, but it is just as easy for me to use the ATF they call for. I always have it on hand too.


Your E-150 must be older to use Type F in the PS. My 1996 Contour also specs Type F, which I use, for the PS. The ATF fluid spec'd was Mercon.

Whimsey
 
Originally Posted by TheLawnRanger
That's what I would've done. I always go by the book. I'm not saying what they were going to do wouldn't have worked, but you were paying them to do the job right which is by the book.

Well put
 
I use PSF in my GM vehicles because that is what it calls for, I use Dex 3 equivalent in my Toyota for the same reason. No desire to change either one
 
Yep like others say get the job done right, it's your money afterall. My understanding was most PSF branded fluid is similar but generally inferior in terms of high temperature stability and shear resistance to quality DEXIII LV and DEXVI ATF fluids. My 12 g37 calls for Nissan PSF or DexVI and I've running Redline D6 ATF in my G37's PSF for the past 5k miles and it seems to work very well. You can change your own PSF fluid very easily with a battery bulb (or turkey baster) and two quarts of the best ATF of your choice for less then $40.
 
Originally Posted by Whimsey
Originally Posted by demarpaint
Both my Jeeps call for ATF+4 in the PS pump, that's what they get. My E-150 calls for Type F fluid in the PS pump, that's what I use. I'm sure PS fluid would work, but it is just as easy for me to use the ATF they call for. I always have it on hand too.


Your E-150 must be older to use Type F in the PS. My 1996 Contour also specs Type F, which I use, for the PS. The ATF fluid spec'd was Mercon.

Whimsey


The E-150 is a 1988. I will only use type F in it. The transmission is the M5OD-R1 transmission, I have some variant of Mobil 1 ATF in it, the exact one is slipping my mind.
 
In response to the original question, it would be preferable to running low fluid, but I would never put power steering fluid into a transmission, especially one that originally spec'd something other than Dexron II/III or Mercon/Mercon V.

Now, I personally would have no issue running a high-quality synthetic power steering fluid in any power steering system. Draw your own conclusions from this VOA on Red Line power steering fluid:

https://www.bobistheoilguy.com/foru...468003/red-line-power-steering-fluid-voa
 
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