Stupid Is As…..or HV Coolant Leak

Discussion in 'Prius c Technical Discussion' started by CMJAnew, Aug 17, 2025 at 1:51 PM.

  1. CMJAnew

    CMJAnew Junior Member

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    Vehicle:
    2012 Prius c
    Model:
    Two
    I spent weeks determining the best replacement HV battery option for a ‘12 with 130,000 miles. Settled on purchasing a local rebuild from a different model ($600) I was to use 20 modules in mine. However, I was outvoted by the lady upstairs. So we purchased a “geak” version with 3 year warranty for a total of $1800 (new 12v included).
    He came and went…..I test drove, only to have the “system warning” come back on. Barely made it home from a 19 mile round trip.
    I screwed around with my cheap code reader….clearing and re-clearing and….
    For some reason I opened the hood and noticed the hybrid coolant reservoir was dry….topped it off….cleared the codes again. The next test drive was FLAWLESS!!!…….Until I got back and noticed the coolant puddle.

    I’ll see if I can find the leak (hopefully an easy to get to hose) later.

    Oh, the tech did ask me if I had it diagnosed prior to disassembly (remember I was going to do it myself).

    Conclusion — Read The Title of this post.
     
    #1 CMJAnew, Aug 17, 2025 at 1:51 PM
    Last edited: Aug 17, 2025 at 4:00 PM
  2. CMJAnew

    CMJAnew Junior Member

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    Update…..Can’t find the leak. Doesn’t appear to be an easy to get to hose. Will be making an appointment…..probably at the local Toyota dealer.
     
  3. BiomedO1

    BiomedO1 Senior Member

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    Have you checked the reservoir tank? I've seen people replace the OEM spring hose clamps with something else and crush the plastic barbs or connection tees - creating a leak after a few warm-up cycles or hot/cold seasons.
     
  4. CMJAnew

    CMJAnew Junior Member

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    I haven’t, but I well. That said….I’m pretty sure it’s coming from the radiator area. I took the plastic ‘under guards’ off, just couldn’t find the start point of the leak. I may have to drive it (get it warm) and observe then. If it’s not a simple hose or tube, it’ll have to go to a garage.