Ok to use iso 46 hydro oil as power steering fluid?

Discussion in '80-Series Tech' started by miked, Mar 18, 2011.

  1. miked

    miked

    Messages:
    633
    Location:
    Imperial Valley, CA
    The pump on my '96 has been whining and though I have a used pump, I thought I would just flush out the fluid first. I've read some good stuff here about ATF vs. hydraulic oil and decided to go with hydraulic oil. I couldn't find the much praised Mobil DTE 24 iso 32 but did pick up a gallon of regular iso 46. I wonder if this oil is too thick. It gets mighty hot down here in the summer so maybe it will thin out.. what do you guys think?
  2. js93cruiser

    js93cruiser

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    2,160
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    roseville, ca
    just use atf i have running it with thousands of miles with no issues
  3. jvazquez53

    jvazquez53

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    San Juan Puerto Rico
    I use Toyota ATF, I would not deviate... The only one other than Toyota, Amsoil.:cheers:
  4. js93cruiser

    js93cruiser

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    2,160
    Location:
    roseville, ca
    same stuff i use, even works great with my hydro assist!
  5. ybhc

    ybhc

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    352
    Location:
    Top of Idaho
    Boring generic chevron Dex III ATF from costco seems to work just fine. I'm not in love with any of toyota's fluids and don't see the need to pay extra to dump their pricey ATF fluid into a hydraulic system as simple as PS. Though I think I'll switch to Toyota coolant when I replace my radiator.

    If I recall, ATF is simply a light hydraulic oil with a few extra additives and detergents, and some red dye. Those additives are meant for the transmission's operation. So whether or not this would be detrimental would depend on if those additives were in any way used by the power steering system. I highly doubt they are since PS is simply a basic hydraulic pump, but--

    In the end, these things have no PS issues with ATF, in any way, so there's no reason I can think of to even so much as bother trying hydraulic oil.
  6. -Spike-

    -Spike-

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    6,163
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    I just recently saw the effects of ATF on a power steering pump when a local club member rebuilt his. Black gunk throughout, and very hard seals. I don't remember if the rebuilder attributed the hard seals to the ATF, but definitely the black gunk, through cavitation and burning of the extra additives that regular hydraulic oil doesn't have, and which don't have any positive effects in a power steering system. I'll be sticking with the plain old hydraulic fluid myself.
  7. -Spike-

    -Spike-

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    Location:
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    I did a search and found some good reading on ATF vs. hydraulic oil vs. power steering fluid. For an information overload, follow the links-
    http://forum.ih8mud.com/80-series-tech/419857-power-steering.html
    http://forum.ih8mud.com/80-series-tech/302241-power-steering-getting-noisy.html
    http://forum.ih8mud.com/80-series-tech/225749-power-steering-fluid-ok-instead-atf.html
    http://forum.ih8mud.com/80-series-tech/162876-power-steering-fluid-type.html
    http://forum.ih8mud.com/80-series-tech/77585-power-steering-flush-after-noise.html

    Tools R Us seems to have quite a bit of knowledge and background on the subject, he explains the differences in detail several times. Cue into his posts if you want the Cliff notes.
  8. Tacoma4life

    Tacoma4life

    Messages:
    330
    After 16 years any fluid will turn black under those harsh conditions, the key is routine service. And the pump calls for ATF, so why use anything else? I love it when people claim they know of a 'better' fluid than what the factory put in. No disrespect to anyone, but it's all speculation.
    Last edited: Mar 19, 2011
  9. miked

    miked

    Messages:
    633
    Location:
    Imperial Valley, CA
    Well, thanks for the replies. With the iso 46 it runs smooth and quiet. What came out was pretty dark. I was just wondering what would be more likely to cavitate.. lighter or heavier.
  10. -Spike-

    -Spike-

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    6,163
    Location:
    Phoenix
    The factory didn't put in ATF, they just suggest it for fill.
  11. What did the factory put in it then, since it says ATF on the cap and in the manual?

  12. -Spike-

    -Spike-

    Messages:
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    Location:
    Phoenix
    I gave 5 (FIVE) links for previous discussions on atf vs. hydraulic fluid. Did you read ANY of them? IIRC every one of them has your explanation. Here's one:
    If you don't like that one, call up any hydraulic pump manufacturer and ask them if they recommend ATF. Power steering is a hydraulic system, with a hydraulic pump. Toyota made it easy for the average Joe to top up their system with a product that is handy. Those of us that push the steering system above and beyond normal and are having issues will benefit from replacing the old mixed fluid with hydraulic fluid. It is documented many times in those links I gave you- that I spent time looking up, but you didn't bother to even peruse lightly- that actual forum users who were having issues and flushed out the old fluid and replaced it with hydraulic fluid have seen improved results. If you want to run ATF, go ahead. It won't void Toyota's warranty- oops, they don't offer one anymore for an 80, never mind. For those of us who tax the system and would like to run something better, hydraulic fluid is the answer.
  13. landtank

    landtank SILVER Star

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    17,235
    Location:
    Groveland MA
    I've been using Mobil DTE24 exclusively for a few years now on every vehicles in the family and my wheeling 80 has a hydraulic winch. It seems to do better than the ATF stuff I was using and it's quite a bit cheaper.
  14. Tacoma4life

    Tacoma4life

    Messages:
    330
    I did read the link and since there's no cited source it's still all speculation. The only thing concrete is what's molded into the cap and written in the manual.

    I've been around enough forums to know that a lot of posts and some general info on a topic doesnt make someone an expert. Again, no offense to anyone.
  15. Jeez, I wasn't looking for "information overload" as you put it, just a simple answer to a simple question as there are many types of hydraulic fluid out there


    Thanks for the response Rick
    Last edited: Mar 20, 2011
  16. stonemasoncruiser

    stonemasoncruiser

    Messages:
    272
    Location:
    minnesota
    I've been around a few forums as well and one thing I've found is mud is no ordinary forum.
    When certain people take the time to respond I know it's not just speculation, it's trail tested
    educated experience.
    Now I've been wrenching on junk for over 30 years and learned from some highly seasoned
    crotchety old timers with more natural skill than 99.999% of any websurf mechanic. I say this only
    because I honestly feel qualified in recognizing advice that is good, educated, and excellent food
    for thought.
    I personally would only use hydraulic fluid in a hydraulic pump.
  17. 86tuning

    86tuning

    Messages:
    2,560
    Location:
    Vancouver BC
    ATF is red, the original fill power steering fluid is clear/yellow on all Toyotas.

    My guess is that it is a hydraulic oil that is compatible with ATF.
  18. Thanks. Never had a "new" toyota and thus had no reference as to what was in there when new.

    By the time I bought mine, in already had ATF in it.
  19. Kernal

    Kernal

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    4,846
    Last edited: May 6, 2011

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