Inverter Coolant Overdue

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Aubstacle, Oct 7, 2024.

  1. Aubstacle

    Aubstacle Junior Member

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    Howdy Y'all!

    I am just today learning about the inverter and its coolant. It's my fault for not keeping detailed notes while googling when I initially bought my 2015 Gen 3 at 74k miles, and my mechanic never mentioned it when I asked about the maintenance schedule or at any appointment since, but here we are 13k overdue.

    I've made an appointment with the dealership, as my mechanic says they do not offer this service.

    But my question is: is 13k overdue going to screw me over?

    Also, can anyone recommend a good hybrid mechanic in the far Western Chicago Burbs, like Naperville/Schaumburg/St. Charles etc. I'm mildly annoyed with my non-hybrid shop.

    Edit to add: car is at 113k miles
     
    #1 Aubstacle, Oct 7, 2024
    Last edited: Oct 7, 2024
  2. Danno5060

    Danno5060 Active Member

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    Just my own opinion. The inverter coolant doesn't seem to be subject to the same conditions as the engine coolant. This makes it less susceptible to the chemical changes that require a coolant change. My engine coolant changed to a bit orange-ish as compared to the inverter coolant still looking just like the factory new coolant. I really don't think the extra 13K is going to cause any real problems.

    Any good mechanic would be able to replace both coolants, but there are a lot of them (who aren't good mechanics) who seem to think that working on a Prius is beneath them. The important thing (again in my opinion) is that they use the factory coolant (available at the dealer's parts department) and don't try to mix it with some aftermarket crap.

    It's really not that hard to do by yourself, but it can be a bit messy. Here's a video on it.



    I don't know much about Chicago, but the guy's shop is in Homer Glen. (TCCN Automotive - Address in the About section of his YouTube channel). Probably a ways away, but hopefully not too far. I don't know about his rates though.
     
  3. Mendel Leisk

    Mendel Leisk Witness Leader

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    What’s the miles on it now?

    FYI: Toyota USA says 15 years or 150k miles for inverter coolant change.

    if you’re missing the Warranty and Maintenance Booklet, a pdf can be downloaded from Toyota Tech Info website (just Google that).

    I’ll post a spreadsheet/pdf table-format translation of the booklet’s schedule in a sec, much easier to read.
     
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  4. Aubstacle

    Aubstacle Junior Member

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    Howdy again,

    My car is at 113k miles. When I downloaded the manual this morning, it indicates this should be done at 100k. But what I’m also confused by is that I don’t see any recommended intervals for the other fluids in the manual. For that I’ve been relying on Prius Chat and my mechanic.

    I had a lot of things preventatively done when I bought the car because we were unsure of its maintenance history at the time.

    I’d LOVE a list of all the fluids/important items and their intervals!
    Thank you!

    Also, my mechanic insists that people shouldn’t be changing their inverter coolant on their own because the hybrid system is involved and special grounding cables are necessary. Is that true? Seems to be s out of people doing it themselves.


     
  5. BiomedO1

    BiomedO1 Senior Member

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    Good Catch!! You'll be OK. If your curious about how bad the issue is, you can do a litmus test of the old coolant. Most people think that they don't need to change it, if they don't live in an area that gets "hard freezes". The reason your suppose to change it is because over time the coolant becomes acidic. I've seen many old iron block engine coolant turn brown from neglect (engine rusting from the inside out; also breaking down internal seals and gaskets). Modern aluminum block engine coolant doesn't change color; but the internal seals, gaskets, electronic components are slowly being eaten away when the coolant goes acidic.

    Hope this helps....
     
  6. BiomedO1

    BiomedO1 Senior Member

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    [QUOTE="Aubstacle, post: 3485186, member:Also, my mechanic insists that people shouldn’t be changing their inverter coolant on their own because the hybrid system is involved and special grounding cables are necessary. Is that true? Seems to be s out of people doing it themselves.[/QUOTE]

    Find another mechanic!! This clown doesn't know what he's talking about!!!

    Have you replaced the ATF?
     
  7. Aubstacle

    Aubstacle Junior Member

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    I’m definitely catching that vibe!

    Yes, I had the transmission fluid changed when I bought the car at 74k miles. I used to drive a 2003 VUE so I’m transmission-traumatized. I’ll do it again at 130k.



    Find another mechanic!! This clown doesn't know what he's talking about!!!

    Have you replaced the ATF?[/QUOTE]
     
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  8. Danno5060

    Danno5060 Active Member

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    Run - don't walk. Get away from that guy as fast as you can. There are special cables for the hybrid system. They're bright orange. You won't need to touch any of them to do an inverter coolant change.
     
  9. Aubstacle

    Aubstacle Junior Member

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    Thank you all for your very helpful responses!

    It looks like I'll probably be doing this myself, but I am waiting for a quote from a hybrid shop referenced earlier in this thread, as he is not that far away from me.

    And yeah I'll run, not walk. :)
     
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  10. Mendel Leisk

    Mendel Leisk Witness Leader

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    At first read yes, and this confuses the hell out of nearly everyone. At the 100k mile service they say:

    upload_2024-10-7_11-5-47.png

    But note the diminutive "3" at the end. If you go two pages forward, you find this:

    upload_2024-10-7_11-5-3.png

    Also, if you look on the side of the inverter coolant, you may see this:

    IMG_5688.jpeg

    This is on the reservoir of my 2010, Canadian spec. FWIW, Toyota Canada says to ignore it and change both at 10 years or (roughly) 100k miles.

    And as mentioned earlier, I've attached Excel and PDF format summary of the American schedule, in easier to read table format (both the as printed schedule, and another where I've extrapolated out to 240k miles..
     
  11. Mendel Leisk

    Mendel Leisk Witness Leader

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    This video is pretty good explanation of the inverter coolant change:



    This video is for the engine coolant change:



    The second one is "mostly" spot-on, but the Repair Manual instruction varies from it, towards the end, instead recommending to refill to the "B" line on reservoir, replace the cap on the reservoir, and run the car till fans come on. I'd say and/or till 30 minutes have past.

    Both of the above videos are linked here as well, plus a lot of others:

    Nutz About Bolts Prius Maintenance Videos | PriusChat

    And I've attached a Repair Manual excerpt, for both engine and inverter coolant change
     

    Attached Files:

  12. Mendel Leisk

    Mendel Leisk Witness Leader

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    The other fluids worth replacing, but NOT mentioned by Toyota USA, are brake fluid and transaxle fluid. See my signature for info on those. If you're viewing on a phone turn it landscape to see signatures.

    I've done all of the above; they're all readily doable, without special equipment. If you can manage an oil change you can do these.