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Inverter coolant leak

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by clealan, Apr 25, 2010.

  1. clealan

    clealan New Member

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    I seem to have a slow inverter coolant leak where the two cases bolt together under the car, between the inverter coolant drain plug and the transaxle drain plug. This is the only place I can find the fluid. You can watch it slowly build up on the bolt head until it drips every few minutes. I am losing about an inch in the resevior every 2 days/100 miles. Does this make sense? I have searched the forums and can't find this problem. I don't even know if there should be coolant in there, but I expect so since the drain plug is right there. 2004 with 63,000 miles, just bought it last week! Help please!
     
  2. edthefox5

    edthefox5 Senior Member

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    Your talking between the 2 cvt halves? Thats not good at all. And yes there's inverter coolant in the CVT to cool the cvt trans. They are piped in and out by the 2 smallish black hoses that are right there. There's not a big area of circulation in the cvt but the coolant is there nontheless.

    Please take some good photo's and post back.

    Did your car get a new transmission before you bought it?

    Maybe you can tighten the bolts up right there. I do not have the exact torgue values for those bolts.
    Other's will post the the torque needed right there on those bolts. But in the meantime try tightening up those bolts a little. One or more may have come loose given the year of your car.

    Don't go crazy on the wrench just tighten it up a little.

    Those bolts have a specific torque range needed to tighten them down properly.
    Most auto stores will rent you a 250 lb torque wrench for free with a $100 refundable deposit.

    Hopefully thats all it is.

    Good Luck!
     
  3. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Tightening torque on the 21 bolts that secure the two transaxle case pieces is only 18 ft.-lb. (13 bolts on one side, 8 on the other)

    Was the car in a front-end accident? Do you see any cracking in the case, or is the leak coming from the seam?

    The case is sealed with Toyota orange FIPG 1281 and a proper repair would require removal of the transaxle, disassembly, and reinstallation. An expensive repair.

    If the car was in a front-end accident that caused the leak, it might make sense to replace the transaxle with a salvage part (from a donor vehicle hit from behind... :cool: )
     
  4. clealan

    clealan New Member

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    Thanks for the replies. It rained today and will rain tomorrow so I can't do much hands on work on the car. I was able to do some research though. I knew the car had slight rear bumper and left rear door damage and negotiated the price accordingly. I bought the car for commuting to work and was more concerned with the mechanical condition. The previous owner had reciepts for all service (even tires) from a local dealer. How thin is the CVT case, anyone know? I am thinking it is likely a small crack. There is a bead of sealer where the cases come together and the coolant isn't dripping from there. It is comming from the bolt head wich is above that ( I checked to make sure the bolts were tight while I was under there). I will try removing that bolt and see if the coolant is coming out of the bolt hole or seepnig out of the case itself. Will post what I find. Any other ideas or suggestions? Thanks again
     
  5. edthefox5

    edthefox5 Senior Member

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    My Chilton's talk about possible cracks in that area due to road damage or accident. The worst part is the coolant could be leaking into the trans itself. rare but possible.

    Its well worth it to put the front up on jackstands and dump the CVT fluid. Its easy. (open the fill hole first) You will need 4 quarts of Toyota WS fluid at I think $9 a quart for replacement. Not sure how many miles on the fluid but dump it a clean container and check it carefully for contamination.
    Should look pretty nice and red with no brown contamination.
    If you suspect contamination you can send it out to and oil lab and have it analyzed real quick for $20. Lots of posters here due this all the time. Google Blackstone Oil Analysis Lab.

    Here's why I think its worth it. Because if worst case coolant is leaking into the trans it will require a trans replacement.
    And you'll know screwed and not waste anymore time on it. But if CVT fluid pretty good and you just have a drip drip try torqueing it up and if it still drips I could live with that for quite a while while maintaining coolant level as opposed to shelling out maybe $3000.

    In the meantime get some spray brake cleaner and hose that leaking area off real good. Clean it up and with a strong flashlight and mirror check for cracks and pay attention to where its leaking. Hopefully its not a cracked case. Post some photo's too.

    Good Luck!
     
  6. clealan

    clealan New Member

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    Got home just in time to jack the car and crawl around under it before it got dark. The coolant seems to be coming from a 14mm bolt above the pass. side axle, running down around the axle housing, down an aluminum fin under the axle and collecting on the rear CVT bolt that comes in from the pass. side. I can get my fingers above the bolt and it seems to be dry. I hope the pictures load. Any one know why there would be inverter coolant at this bolt? That overflow hose would be up there somewhere, but it leaks even when the car isn't running. I will have to investigate further tomorrow. It will be hard to get a wrench in there! Any and all opinions welcome.
     

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  7. edthefox5

    edthefox5 Senior Member

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    Very perplexing. Good photo's thanks. In PHOTO #1 which bolt head are you concerned about? The one on the right with the bright colored green or the one closest to the cvt boot? That one looks like its wet with nasty old cvt fluid.The green one is not bad at all. But,....I don't think thats where the coolant area is though on either of those bolt heads. I'm not sure. The coolant circulation area is very small on the cvt. I need to stick my head under mine to get oriented. Its right hwere the both black hoses enter and leave.

    Photo 2 on the right is perplexing. What's the green on every bolt head? Is that your concern? That cannot be coolant leaking as coolant does not go there.
    Is that factory tightening sequence marking maybe. Phot 2 is not an issue I think.

    That one bolt head with the ugly looking fluid makes me want to dump the trans fluid asap.
    Spend the $40 asap and do that. If the fluid is contaminated your done.

    But....if fluid cool and its just that one weepy bolt head I could live with that for quite a while. A real long time! Drippy inverter coolant is not that bad as long as you diligently keep the reservoir up and don't beat the shit out of the car. Watch that reservoir and you should always have lots of circulation/movement in that reservoir.

    Compare a daily topping off against at least a $2000+ repair (unless you can eBay a CVT replacement yourself and replace it yourself)
    But the worst part about that is you will be installing a used CVT anyway no matter where you buy it that may be in worst shape then your leaking one.

    Check the fluid and let us know. I don't think you have a bad issue here.
     
  8. clealan

    clealan New Member

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    Of the three bolts in photo 1, it is the center top. if you look close you can see a coolant stain coming down from there. judging by where the coolant hoses are on the CVT, this is too high to be coming from the CVT. I have to try to orient top to bottom when I have light, but I'm thinking that it may be dripping straight down from the bottom of the resivoir, or somewhere up there. That would be great. The second picture is just because I felt bad for saying it was coming from the CVT seam. You can see a drip forming below the far left bolt of the three. It doesn't look like coolant now because I have been adding filtered water from my refridge door until I can find the leak. I will do the trans. drain and fill today and the inverter coolant when I find the leak (or give up).
     
  9. edthefox5

    edthefox5 Senior Member

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    None of them are real concerning to me unlss I'm not seeing it correctly. Just a little weepy.

    When you go to drain make sure you open the trans FILL hole first.
    And before dumping check the trans fluid level with your finger. See how low it is. After the dump and refill use spray cans of brake clean (I like choke cleaner too) and clean that trans off really good with cleaner and rags. Scrub all the corrosion off real good. SCrub the trans clean as best you can.

    Then Tighten all the bolts you can get to to there exact torque spec. Note which were loose and which tighten up properly. You may have a stripped bolt.

    Don't use clear water in the inverter as dilution of the coolant will cause corrosion in the inverter and also you will not be able to see leaking without the colored die. Use the correct style coolant for the inverter from Toyota.

    And then watch it closely. You may just have a weepy bolt or two.

    Just don't let Inverter Coolant level go low.

    Good Luck.
     
  10. Patrick Wong

    Patrick Wong DIY Enthusiast

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    For those bolts that are weepy, I am wondering whether it would help to remove them, one at a time, and put blue Loctite on the bolt threads before reinstalling.
     
  11. BAllanJ

    BAllanJ Active Member

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    Ummm.... in that second pic.... Is there a bolt missing?
     
  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    If you are referring to the left side of the second photo, the bolt is coming from the other side of the transaxle. You can see the tip of the bolt if you look through the threaded hole.
     
  13. clealan

    clealan New Member

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    So... the leak is definitly coming from above the transaxle(fluid looked pretty god BTW, hasn't been in there 60k). Since all the plumbing is on the front side of the engine/transaxle, the only place I can see to get a drip down the back side is from the reservoir itself or where it bolts to the inverter(see diagram). It is impossible to see under the res. and impossible to get to the bolts to remove it as far as I can see. Local dealer says $75 labor plus parts to replace the res. Since the hood,air box ect. was damaged in a front end collision, and the res. is plastic and right there, I think this might fix it. What do you guys think?
     

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  14. 2009Prius

    2009Prius A Wimpy DIYer

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    Is it possible to reach under and feel for signs of leaks with a finger?
     
  15. clealan

    clealan New Member

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    Not with my fingers. Maybe a piano player could get in there! I just went to the dealer and ordered the tank, $41, should be here monday. $75 labor plus shop supplies ect. I spent hours yesterday looking for a way to get it off without removing a bunch of electrical stuff i'm scared of, TIS shows removing the inverter! I really think it's coming from the tank, but it will be worth it to me just to eliminate that possibility. At least the CVT is OK, thats a relief. I will keep you posted.
     
  16. clealan

    clealan New Member

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    That gave me an idea. I wrapped a paper towel around a peice of wire and pushed it around under and behind the reservoir. I got mostly dust but one small spot of pink back where the res. flange bolts up to the inverter. I also found a crack (evidence of impact!) near the rear bolt on the reservoir. See pics.
     

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  17. 2009Prius

    2009Prius A Wimpy DIYer

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    Good find! Let's hope that's the source of the leak and after the replacement you will be all set. Good luck! :)
     
  18. SageBrush

    SageBrush Senior Member

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    May we call you Sherlock ?
    Good job, and good luck !
     
  19. Patrick Wong

    Patrick Wong DIY Enthusiast

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    $75 is a fair labor price.

    If you remove the cowl that contains the windshield wiper motor and the wiring harness that runs across the engine valve cover, you might gain access to the three bolts that hold the inverter reservoir to the inverter.
     
  20. BAllanJ

    BAllanJ Active Member

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    Thanks Patrick. I thought it might be a stupid question. I did notice the end of the bolt, but thought that may have been what was left of a snapped off bolt. But since you can see that the hole is threaded, the bolt comes from the other side. It does seem an odd design that would make it a bit awkward to tighten all the bolts in a nice orderly fashion.

    To the OP... congrats on finding your leak.:thumb: