Couple questions about Prime coolant change.

Discussion in 'Prime Care, Maintenance and Troubleshooting' started by The Big Sleaze, Sep 25, 2023.

  1. The Big Sleaze

    The Big Sleaze Member

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    I heard about some lengthy process, but this seems fairly straight forward.
    1)Open engine and inverter coolant filler caps.
    2)Drop the under panels to get to 2 yellow drains on driver's side.
    3)Drain both coolants.
    4)Close drain valves.

    (now this guy IIRC replaces the under panels THEN fills and runs to 'burp'. I'm gonna fill, run to burp, check for leaks, let it cool back down, THEN do the under panels)
    5)Replace panels.
    6)Run to burp system and refill as level of Inverter drops.
    7)Replace filler caps.

    This guy does some fancy thing to put it in "maintenance mode" but vid is older and not of a Prime. I think I'll just start with fairly low traction battery so it can be in CRG mode for a while.


    Questions are: What is coolant capacity for both engine and inverter? How much do I need to buy?
    In second video the guy says its important to eyeball that the coolant in inverter is showing motion, so its not cut off by some big air bubble. He also lets it start engine cooling fans twice as per specs.
    Does the coolant ever want to boil up and out like with old cars? Video was shot out of sequence so do you replace caps with engine still running?
     
    #1 The Big Sleaze, Sep 25, 2023
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  2. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Attached are Toyota Repair Manual instructions. Doesn’t matter Prime or not. Two gallons of Toyota Super Long Life Coolant should do.
     

    Attached Files:

    #2 Mendel Leisk, Sep 25, 2023
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  3. The Big Sleaze

    The Big Sleaze Member

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    Thx! Where does one get that full manual?
    Got the sheets for Spark Plug replacement and Brake Pad replacement?
     
    #3 The Big Sleaze, Sep 25, 2023
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  4. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Will take a look. :)
     
    #4 Mendel Leisk, Sep 25, 2023
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  5. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Attached:
     

    Attached Files:

    #5 Mendel Leisk, Sep 25, 2023
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  6. The Big Sleaze

    The Big Sleaze Member

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    THANKS!
     
    #6 The Big Sleaze, Sep 27, 2023
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  7. Naimc

    Naimc Junior Member

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    @The Big Sleaze , This is on my list to do, did you you go ahead and do it ? how did it turn out .

    Also regarding your question about where the service manual data come from, You can purchase a 2 day Toyota Techstream subscription and have access to all the service data online. https://techinfo.toyota.com/techInfoPortal/appmanager/t3/ti?_pageLabel=ti_whats_tis&_nfpb=true

    But I have to say that is very nice of @Mendel Leisk to provide this info. It takes a lot of time to download these files into local PDF files.
     
    #7 Naimc, Oct 16, 2023
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  8. ChapmanF

    ChapmanF Senior Member

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    #8 ChapmanF, Oct 16, 2023
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  9. Naimc

    Naimc Junior Member

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    Did the coolant change on our 2017 at 103000KM, I wanted to use pH strips 1st to determine if the coolant was acidic but i did not find them. While I was under the car looking at all the hose I was able to remove 3 going into a a lower manifold and more coolant came out.

    upload_2024-11-1_0-35-57.png

    upload_2024-11-1_0-36-47.png

    Oily substance when I drained these bottom hoses, that might have come from the Woolwax rust proofing I did recently on the metal hose clamps.

    upload_2024-11-1_0-38-7.png

    I did the fill using an OEM coolant device that creates a vacuum in the coolant system. When I the system was de-pressurized I left it for 10 min and no air leaked in.

    upload_2024-11-1_0-39-46.png

    Used 1 gallon and 1/3 of the other :

    upload_2024-11-1_0-40-23.png

    I did the inverter cooler the same way :

    upload_2024-11-1_0-41-4.png
     
    #9 Naimc, Nov 1, 2024
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  10. ETP

    ETP 2021 Prime(Limit),24 Venza Limit,B52-D,G,F,H

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    Great thread! Having a certified independent shop do it on 3 March 2026. I wanted to make sure they were up to speed on my 2021 Prime.

    I assume this is good for the 2021 Prime??????
     
    #10 ETP, Feb 21, 2026 at 12:51 PM
    Last edited: Feb 21, 2026 at 12:57 PM
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