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Slight leak after transaxle fluid change

Discussion in 'Generation 1 Prius Discussion' started by tada, Apr 7, 2018.

  1. tada

    tada Member

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    Today I changed the transaxle fluid out, dropped and cleaned the pan and magnet, and installed a new OEM gasket. I torqued all the pan bolts down to 67 in lbs and the fill and drain plugs to 36 ft lbs.

    As soon as I added the ATF, I saw leaks in the rear gasket area. I snugged up all the bolts a little more - probably another 10 in lbs or so - and the visible leak is gone.

    But I just checked on it again and I can slide my finger along the rear portion of the gasket and get liquid on my hand. The front is dry. Should I try to tighten the pan up a little more?
     
    #1 tada, Apr 7, 2018
  2. sandy11246

    sandy11246 Member

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    Did you confirm all the bolt holes in the pan were not previously over torqued. If they had been over torqued, the hole would be bent in slightly. Also make use all bolts have washers installed. At this point, I would suggest make sure all bolts are evenly torqued and drive the vehicle until the trans reaches operating temperature, giving the gasket a chance to seal, then recheck torque and check for leaks. Good Luck. Peace.
     
    #2 sandy11246, Apr 7, 2018
  3. Brian in Tucson

    Brian in Tucson Active Member

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    I would drain the nice clean atf into a clean container--a large cook pan would do or a new bucket from Dollar Tree. Heck, they're only a dollar. Then I would undo all the little screws and drop the pan for inspection--again. Check the mating surfaces in question. Fix whatever's wrong and re-install the pan and gasket and torque it to spec. I wouldn't keep tightening the fasteners, too easy to strip the aluminum threads which would be bad, very bad.

    Not a bad thing to keep a supply of 5 or so clean buckets on hand. You can clean up with Dawn. btw.
     
    #3 Brian in Tucson, Apr 8, 2018
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  4. tada

    tada Member

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    I’ve been monitoring the pan closely. There is no actual dripping or seepage coming down the pan. It may just be residual fluid from when it leaked before tightening.

    I plan on changing it again in 30000 miles. For now I’ll monitor it. If it looks like it worsens, I’ll just do the whole change again with a new filter and a new pan that I know hasn’t been overtorqued.
     
    #4 tada, Apr 8, 2018
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  5. Pttaylor9

    Pttaylor9 Junior Member

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    #5 Pttaylor9, Jun 6, 2018
  6. Pttaylor9

    Pttaylor9 Junior Member

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    Just curios, I've watched a lot of videos of people draining and refilling the trans fluid but none dropping the pan like you did. Was there any sludge in your pan? Is there a filter in there?
     
    #6 Pttaylor9, Jun 6, 2018
  7. LEVE

    LEVE Member

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    That pan is pretty thin metal and it grows and shrinks with the heat - cool cycle.

    What would I do? I'd sure drop the pan again and examine it for warpage and examine the mating surface. In the past here are some of the things I've done to repair transmission ATF pan leakage:
    • Add a 2nd CORK gasket
    • Use sealer like "Form a Gasket" on both sides of the gasket
    • Made my own cork gasket
    • Made metal spacers to spread the load of the pan bolt along the pan mating surface.
    • Actually peened the pan, and tweaked it's mating surface when it was warped
    Would I let this continue? No, I would not for the following reasons:
    • I don't like my Prius "Marking its Territory", so to speak. I hate leaks.
    • There is always a chance of it getting worse while at highway speeds and draining your fluid in no time at all. That leaves you high and dry replacing some pretty expensive parts for the sake of fixing a drip. It's the story of "For the sake of a nail the shoe was lost." Fix it now, neither forget it or ignore it. It's not going to get better.
    • I hate having a problem with my car and not knowing the fix, or what's wrong.
     
    #7 LEVE, Jun 6, 2018
  8. tada

    tada Member

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    There was a slight amount of sludge in the bottom that I had to wipe out with paper towels. There is also a small square magnet to collect up small metal bits. There was some fine metal bits, but not much. There is no filter.

    As for leaking, after I tightened two of the bolts, I have had no leaks. I hate a leaking vehicle as well. I rebuilt a 1966 Triumph Spitfire that leaked no matter what. When I do the next transaxle fluid change, I’m replacing the pan. I like to know the history of what I have. And I prefer a new pan over additional gaskets or sealer.
     
    #8 tada, Jun 6, 2018
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