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[DIY] ICE & Inverter Coolant Replacement

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by mindfk, Oct 12, 2015.

  1. mindfk

    mindfk Junior Member

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    Hello,

    I'm coming from Audi/BMW background where there is a DIY for most of the maintenance jobs and you can find a scanned repair service manual for any year/model...

    I want to contribute to the forums because I found some useful information here and I haven't seen a good DIY for coolant replacement for 3gen. I have 2010 Prius V (five).

    Things you will need:
    - coolant - I used "OEM Concentrate extended life Pink radiator antifreeze coolant" Part # 86-174POEM, SKU: 879899 from my local Pepboys. My local dealer did not have a pink coolant concentrate (and I did not fancy to pay $24/gallon of 50/50) and the specs for the alternative meet Toyota's coolant. I paid $21 for concentrate and $0.88 for distilled water...use whatever you like, this ain't an oil thread. Mixed coolant yielded 2 gallons of 50/50.
    -a pan to drain old fluid
    -tools to remove plastic rivets
    -10mm socket
    -10mm hex for inverter coolant drain
    -my custom tool to loosen coolant bleeder valve at the top of the engine

    Engine bay: right side - inverter coolant, left side - ICE coolant
    YDXJ1124.jpg

    Remove the belly pan with all its bolts and plastic rivets
    YDXJ1127.jpg YDXJ1129.jpg

    This is how the inverter coolant drain will look like, we will do that first:

    YDXJ1130.jpg YDXJ1131.jpg

    Inverter coolant capacity is approximately 2.1 Liters = 2.2 Quarts

    Remove the 10mm hex coolant drain:

    YDXJ1134.jpg YDXJ1135.jpg YDXJ1132.jpg

    Give it few minutes and then reinstall the bolt with 29ft/lb of torque. I reused my aluminum washer.

    Fill the inverter coolant reservoir tank until it is at the FULL mark, I used Techstream to start the inverter pump and circulated the fluid, it seems like the system bleeds automatically. Screw the inverter reservoir coolant cap back on the reservoir and you're done.

    Now let's move to the ICE coolant.

    YDXJ1125.jpg
    YDXJ1136.jpg

    Go under the car and look for the radiator drain:

    YDXJ1137.jpg
    YDXJ1139.jpg
    YDXJ1140.jpg YDXJ1143.jpg

    I also blew into the coolant reservoir to remove as much coolant as I could.

    Now we will look at the back of the engine to drain the engine block:

    YDXJ1145.jpg

    Proceed with draining the block. In my case, blowing into the coolant reservoir resulted in no fluid in the block...funny thing....Torque for this little guy should be 9ft/lb so take it easy.

    Close all the drains you used and begin filling the ICE reservoir (capacity 7.3 Liters (7.7 Quarts) with exhaust recirculation, 6.5 Liters (6.8 Quarts) without exhaust recirculation), when done, check for leaks. Fill to the FULL mark on the reservoir.

    When filling you should loosen the coolant bleeder valve, close the valve when you're done filling the system.

    YDXJ1122.jpg
    YDXJ1147.jpg

    You can steal my patent and use a bent piece of metal as a big stubby screwdriver :)

    YDXJ1149.jpg YDXJ1150.jpg

    Take it easy, all these bits are plastic and it is easy to break something, this L shaped piece of metal should be easy to fit under the windshield panel, if you want, feel free to remove the engine cover for more space.

    You are now ready to bleed the system. Put the car into maintenance mode to allow for proper ICE warm up, the coolant thermostat opens at around 190*F.

    Wait for the car to fully warm up, set high heat and fan to low - 1 bar. Full warm up will take few minutes.

    This is when I started checking the bleeder valve from time to time to make sure I have no air in the system. If you want to find out when the thermostat opens, feel the radiator hoses underneath the car. It should take approximately 10 minutes to get the car to 190*F. When you will feel that the hoses are warm, bleed the system one more time and fill up the reservoir to the FULL mark. This completes the bleeding procedure. Exit the maintenance mode now.

    Put back the belly pan and take your baby for a spin. You just saved yourself 200 dollars...

    Have fun!

    PS: I'm not responsible for whatever you guys do, this is just for your information. I'm not a mechanic and don't take my advice seriously. Also, in my attachments you can see few scans from the shop manual describing the coolant replacement process.
     

    Attached Files:

    #1 mindfk, Oct 12, 2015
    Last edited: Oct 12, 2015
  2. Mendel Leisk

    Mendel Leisk Senior Member

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    Thanks for this. A very thorough how to. The one thing I find daunting is techstream. If you don't mind, a couple of comments:

    1 For the first startup to get into maintenance mode: should that be WITHOUT foot on brake pedal?

    2 Considering the infrequency of this maintenance, I'd say use the the Toyota fluids, and unless they're not readily available, replace the washers.
     
  3. mindfk

    mindfk Junior Member

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    - I wasn't sure about the steps as this is the first time I did it, I edited my post to exclude the maintenance mode procedure. I'm sure people can just search youtube or the forums for detailed instructions.[/QUOTE]
     
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  4. Suprius

    Suprius Junior Member

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    Did Toyota change remove the air release valve from the 2012 Prius? It does not have any screw to loosen. Since I don't have ICE coolant bleeder on mine, is their another method for the 2012s? I've attached the picture of what it looks like on the 2012.
     

    Attached Files:

  5. Mendel Leisk

    Mendel Leisk Senior Member

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    On my 2010 it looks like that, except there's a white plastic cap, knurled, with a slot across the top.

    You have the wipers and cowl off for that pic?
     
  6. NutzAboutBolts

    NutzAboutBolts Senior Member

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    I believe the 2012 Prius doesn't have a bleeder valve. But it shouldn't affect how you would do the service, which would be the same without using the bleeder valve.
     
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  7. CR94

    CR94 Senior Member

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    Would one instead have to disconnect a nearby hose temporarily to let trapped air escape?
     
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  8. Suprius

    Suprius Junior Member

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    Yes, I removed it to make sure I wasn't missing anything lol
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Nutzaboutbolts has started a thread for 3rd gen coolant changes. As usual, with start to finish videos!
     
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  10. NutzAboutBolts

    NutzAboutBolts Senior Member

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    No, I think the bleeder valve has a valve to bleed air out from there, if you disconnected the hose and bleed air out from there, it would defeat the purpose and will probably cause more mess than needed. The engine warms up quicker than my Honda Accord when I do my coolant drain and refill. So just run the engine and wait till the radiator fan kicks on, the air should be bleed by then.

    As for the bleeder valve, my 2012 Prius doesn't have that white cap either, they must have updated the vehicle on certain parts. There is no twisting motion either so it's basically a plastic sealed tube.
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    I continue to be puzzled by the bleed bolt deletion. I've yet to do Prius coolant change, but with Hondas the drill was to leave the bleed bolt open as you fill, until coolant start coming out, then shut it. While it's open, and if you're pouring coolant in fast, you can feel a strong gust of air coming out of the bleed bolt, that's got to be helpful. Our 2010 at least has the bleed bolt.

    Also, seems strange that there's not radiator cap.

    Anyway, your videos show how to do it, and it gets done. (y)
     
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  12. CR94

    CR94 Senior Member

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    The cap must be the highest point in the system.
     
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  13. Hjeff

    Hjeff Junior Member

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    The bleeder is missing on my 2011. I just popped the wire off of the temperature sensor, unscrewed it, and BURRRP!
     
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  14. Mendel Leisk

    Mendel Leisk Senior Member

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    I thought the bleeder valve delete was in 2012, strange. Yeah I think if you were to pull off a topmost hose at the EGR, it would accomplish the same thing: fill till coolant starts coming out, then quickly push the hose back on. Be easier with an assistant doing the pouring.
     
  15. Peter123

    Peter123 Active Member

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    If you start and stop the engine several times going from cold to hot and back to cold again, then the trapped air will be carried out by the coolant. Your overflow tank level will go down as a result. The air is entrained by and dissolves into the coolant.
     
  16. mjoo

    mjoo Senior Member

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    Homebrewing 101: One way to remove "entrained" air in water is to boil it.
     
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  17. abubin

    abubin Member

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    Very good guide on bleeding coolant! I have done changing coolant for my inverter quite some time ago. However, I am not very happy with the temperature. The inverter seems to be running a tad bit warm. I am looking to see of I missed something during the inverter coolant replacement. So seems like I missed on doing the bleeder valve part. The tutorial I followed in youtube does not mention about this bleeder valve. And I cannot find much information on it. Lots of mention on Gen2 but not on Gen3. So can I know more information on how this bleeder valve works? Without tinkering with the bleeder valve, what are the consequences?
     
  18. Raytheeagle

    Raytheeagle Senior Member

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    How do you know your inverter is running hot:whistle:?

    If you have run the car for a period of time after the drain and refill and the level is stable, job done;).

    If there is a dash light, there is a code present or if you've had issues with your Prius cutting out at speed, that could be the inverter water pump:).

    But it doesn't sound that way, so let us know how you got the too hot data(y).
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

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    Bleeder valve was on the engine coolant circuit.
     
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  20. abubin

    abubin Member

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    I uses Hybrid Assistant app. It will show a lot of sensor readings and one of them are the temps. The below screenshot I taken from google but the example is shown in the red rectangle. Yellow usually means warning temp, not severe yet. In my case, my inverter temp is always around 55c (130f). Inverter temp should be less than 50c (122f) to be in "green".

    upload_2020-8-12_10-28-28.png