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Coolant in the transmission fluid?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by nate358, Mar 30, 2022.

  1. nate358

    nate358 Junior Member

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    I am changing the transmission fluid on my 2012 and the fluid that came out was dark red and creamy. I had a Toyota dealership change the fluid 40k-50k miles ago and I vaguely remember they didn't put ATF WS in it but some other kind of ATF... I could be remembering the incorrect because I had them change the engine coolant any maybe it wasn't super long life they put in. I'll have to look at the paperwork. But, is it possible for inverter coolant to somehow find its way into the transmission? I know if a head gasket goes, engine coolant can find its way into the engine oil... But just trying to figure out what would make the ATF cloudy.

    Posted via the PriusChat mobile app.
     
    #1 nate358, Mar 30, 2022
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Toyota ATF WS is red. Considering the emphatic warning in Owners Manual (not to use anything else) it’s doubtful a dealership would use a substitute. Is it oily feeling, same as your new fluid (assuming you purchased ATF WS)?
     
    #2 Mendel Leisk, Mar 30, 2022
  3. Mdv55

    Mdv55 Active Member

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    Aeration and moisture could cause that depending on how you would describe creamy.

    If it's been super humid out, the car sits a lot, is short tripped all the time and/or the fluid was changed cold I wouldn't be surprised if it looked funky when changed.

    Getting up to temp for a long time removes moisture from ATF just as it does from engine oil.
     
    #3 Mdv55, Mar 31, 2022
  4. nate358

    nate358 Junior Member

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    I revisited the paperwork done at the dealership in 2019 and all fluids used were correct.

    Posted via the PriusChat mobile app.
     
    #4 nate358, Apr 2, 2022
    Mendel Leisk likes this.
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