Toyota's Insistence on using ATF in power steering

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I have a 1989 Toyota Soarer, which is a JDM only car, but in a nutshell, many of the parts are the same as the mk3 supra, or cressida of the time.
I recently got the car fixed, including the power steering, but I dont really know what fuild did the mech put in for the power steering. It
feels a tad heavy after some time driving. I will try to find out , but It seems its written on the fill reservoir to use DEX II or III ATF for the power steering
So a question for you older toyota owners, is it common for hydraulic power steering toyotas to work better with ATF than PS fluid ?
 
Americans would probably know the Soarer as a Lexus. DexII, DexIII, PS fluid, they will all work just fine.
 
It is possible that since your power steering has been fixed that, it feels heavy or firm compared to needing the repair???

From my understanding, power steering fluid and ATF are the essentially the same fluid type maybe with different additives. But as stated, Dexron ATF is what Toyota required at that time.
 
ATF isn't the same as "power steering fluid" (whatever that is) but many manufacturers have specified ATF for Power Steering over the years. It has the good properties that work well in a PS pump like low foaming and good pressure stability.

But ... there are differences in hydraulic oils in the composition and it affects things like seal compatibility. So if the manual says Dextron III then use that; if it says something else then use the something else.
 
Originally Posted By: Char Baby
It is possible that since your power steering has been fixed that, it feels heavy or firm compared to needing the repair???

From my understanding, power steering fluid and ATF are the essentially the same fluid type maybe with different additives. But as stated, Dexron ATF is what Toyota required at that time.

Car was sitting on the lot for 2 1/2 years, I am unsure how its supposed to feel. The pump was whining and leaking thats why I had it rebuilt. After rebuild, when the car is started, steering feels light, after engine warms up, 20 min+, the steering feels noticeably heavier. yes there is speed sensitive valve, but even when the car isnt moving, after warm up the steering feels heavier than at cold start.
 
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Originally Posted By: Johnny2Bad
ATF isn't the same as "power steering fluid" (whatever that is) but many manufacturers have specified ATF for Power Steering over the years. It has the good properties that work well in a PS pump like low foaming and good pressure stability.

But ... there are differences in hydraulic oils in the composition and it affects things like seal compatibility. So if the manual says Dextron III then use that; if it says something else then use the something else.

I have a nagging feeling you are right.
 
Originally Posted By: alcyon
Originally Posted By: Johnny2Bad
ATF isn't the same as "power steering fluid" (whatever that is) but many manufacturers have specified ATF for Power Steering over the years. It has the good properties that work well in a PS pump like low foaming and good pressure stability.

But ... there are differences in hydraulic oils in the composition and it affects things like seal compatibility. So if the manual says Dextron III then use that; if it says something else then use the something else.

I have a nagging feeling you are right.


^^^And I agree with this comment/statement about using the correct P/S fluid for each app. I had read somewhere(IIRC, here @ BITOG) that the fluids(P/S & ATF) start out the same and that P/S fluid is nothing more than ATF of some kind. However, I don't really know for sure and I am not going to do a search only to find nothing or that I was mistaken.

Point taken,
CB
 
ATF and PS fluid must be close in properties. GM called for PS fluid in the PS systems of the Traverse, Acadia and Enclave, but changed it over to ATF around 2011. These vehicles came on line in 2007. I went to change out the power steering fluid in a friends 2011 Traverse and was surprised to see a new label on the cap to use dexron VI ATF. Previously it used PS fluid. I remember them having to take it in due to PS issues to the dealer.
 
Dex VI seems to be a really good PS fluid in a lot of vehicles-the Mercury Grand Marquis in my sig used Mercon (regular, not V) from the factory-fluid was almost black & the PS pump would make noises & act up when below 0C/32F. A return line fluid exchange with Super Tech Dex VI & it's a LOT better.
 
I like using ATF for power steering - one less fluid to have floating around. Dex VI in the Burb and Mercon V in the Vic. The Escape doesn't even have PS fluid since it's electric power steering.
 
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Originally Posted By: 901Memphis
In my limited experience the reman rack never feels as good as the oem


It depends on who did the rebuild, some are much better than others but you are right something like a Cardone, Nastra, BBB, Atsco or other junk is not much better than a piece of rope through two holes on a piece of wood up front.
 
Almost every car lets you use ATF in the power steering. The only ones that don't are Honda, and some European cars.
 
Is it me or do I see Honda using [censored] seal materials and that is why there are so many failures with their PS systems with ANY kind of GOOD oil. Like Honda ONLY uses group 2 loving seals for their group 2 PS oil. Any group 4 and 5 = failure.
 
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Originally Posted By: 901Memphis
In my limited experience the reman rack never feels as good as the oem


Concur and towards that a lesson learnt is never ever do steering locks under load. Find a way to completely avoid it.
 
On Power steering, ATF will produce heavier feeling compared to the lighter weight power steering fluid (Honda, or Redline PS). I have the same synptom when I replace my Toyota PS fluid with Lubegard complete. So far it never whines, but personally I prefer the Redline PS fluid compared to their D4 ATF for the toyota power steering. I believe the similar phenomenon happen when you change the standard DOT 3 brake fluid with DOT 5.1 that typically lighter as well.
 
Originally Posted By: kr_bitog
On Power steering, ATF will produce heavier feeling compared to the lighter weight power steering fluid (Honda, or Redline PS). I have the same synptom when I replace my Toyota PS fluid with Lubegard complete. So far it never whines, but personally I prefer the Redline PS fluid compared to their D4 ATF for the toyota power steering. I believe the similar phenomenon happen when you change the standard DOT 3 brake fluid with DOT 5.1 that typically lighter as well.


Honda's fluid is heavier than ATF

I think the Honda PS is around 11 Cst. Compare that to Dexron III (around 8 Cst) or Dexron VI (around 6 Cst)
 
Originally Posted By: slacktide_bitog
Originally Posted By: kr_bitog
On Power steering, ATF will produce heavier feeling compared to the lighter weight power steering fluid (Honda, or Redline PS). I have the same synptom when I replace my Toyota PS fluid with Lubegard complete. So far it never whines, but personally I prefer the Redline PS fluid compared to their D4 ATF for the toyota power steering. I believe the similar phenomenon happen when you change the standard DOT 3 brake fluid with DOT 5.1 that typically lighter as well.


Honda's fluid is heavier than ATF

I think the Honda PS is around 11 Cst. Compare that to Dexron III (around 8 Cst) or Dexron VI (around 6 Cst)


Hmm..perhaps my memory serves me wrong, I thought I remember when I research on Redline PS for my Toyota, there has been comments that the Redline PS is thinner than typical ATF and there is one manufacturer specifically recommend it for PS..but can't remember what it is if not Honda. My apology!
 
I'm not sure why Toyota says to use ATF, but if they call for it, use it.

I once worked with a guy who installed a rebuilt P/S rack on a VW cabrio. The car called for ATF, but 5 days later, another repair shop called us and said that the rack failed and someone used PSF instead of ATF.

If you want the best for your car, just buy a premium synthetic ATF.
 
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