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Engine + Inverter Coolant DIY

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by BlueOfLA, Oct 3, 2018.

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  1. BlueOfLA

    BlueOfLA Junior Member

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    Hi PC,

    I just did an Engine+Transmission swap in my 2008 Prius and the last step in my home repair is Engine and Inverter coolant. I found 2 wonderful guides online about refilling the coolant here:
    Coolant System Flush | Exclusively Hybrid

    Not wanting to start the car just yet since I want to bleed both systems, and I don't want to overheat the inverter or engine while bleeding - is it possible/acceptable to remove the CHS W/P relay and INV W/P relay and short them so that I can run the pumps individually without turning the car on or plugging in my laptop?


    -Blue
     
    #1 BlueOfLA, Oct 3, 2018
  2. exstudent

    exstudent Senior Member

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    You are making life more difficult that it needs to be.

    1) Just follow the procedure Patrick Wong outlined when he replaced his engine water pump and inverter water pump.
    OR
    2) Get an AirLift to refill the coolant. There is a reason shops use this tool: saves them time! This tool in theory refills the cooling loop w/o any air left behind. However, my experience has been there is some residual air left behind, albeit VERY little, as I have to add a few ounces into the radiator for the engine loop. The Inverter loop has always been perfect; no residual air, no need to top off.

    Remember the inverter loop is EASY and near idiot proof.

    Bleeding the engine loop the traditional way will need all three pumps to move the fluid and help push air out to the radiator neck:
    *belt driven water pump (engine needs to be on)
    *CHRS pump
    *heater core pump (you completely forgot about this one)

    You have Techstream too?
     
    #2 exstudent, Oct 4, 2018
  3. BlueOfLA

    BlueOfLA Junior Member

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    Thanks for the response exstudent

    I think because I keep seeing comments about how difficult the cooling loops are it worries me that I'll have a bunch of air trapped in my system while it may be easier than made out to be?

    Inverter:
    -Fill reservoir until the coolant starts coming through the bleed valve
    -Bleed valve open and fed into the fill reservoir, turn to IG-ON : until the air escapes the system, disturbance in the reservoir, hum from pump.

    I do have Techstream, for the Engine shall I:
    -Fill radiator until fluid comes through the bleed valve
    -Run Techstream bleed procedure


    Is that all there is to it?
     
    #3 BlueOfLA, Oct 4, 2018
  4. exstudent

    exstudent Senior Member

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    Having done older cars myself and reading other peoples experience with the Prius, the big difference is probably PATIENCE. It is a little more involved b/c of CHRS for the engine loop. The Inverter loop itself is straightforward and simple.

    However, I wanted to bypass all that and purchased an AirLift tool; once you experience this, you can NEVER go back the traditional way. The correct tool makes a world of difference. Kinda like a 1/4in imact driver drill; makes life easy driving screws/bolts.

    You still want to check directly in the radiator, over a few days, to make sure the coolant is at the top, after a few hot/cold cycles. Best to open the radiator in the morning, after the car has cooled OVERNIGHT; I made the mistake of thinking cool to the touch (engine & radiator), after 6 hours was enough. Nope, the system was still pressurized.

    READ Patrick's procedure and decide for yourself.
     
    #4 exstudent, Oct 4, 2018
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  5. BlueOfLA

    BlueOfLA Junior Member

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    I'm struggling even with the Inverter loop, I suppose that makes me an idiot or impatient. In the thread you link Patrick says,
    I've filled the coolant reservoir and it stays at FULL, however when I turn the car IG-ON the fluid level does not drop after 20+ seconds. IG OFF, open bleed valve, no air, just fluid. But there is no turbulence in the coolant reservoir and when I squeeze the tube that feeds the inverter I hear a sloshing sound as if there is air inside. I guess I should drain the transaxle again and start over?
     
    #5 BlueOfLA, Oct 4, 2018
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Do not drain the transaxle coolant again.

    Do you hear the inverter coolant pump running, when you make the Prius IG-ON? If you do not hear the pump running, then you need to figure out whether the pump failed or you have a problem with the wiring harness associated with your having previously removed the engine/transaxle.

    If you do hear the pump running, but the fluid level does not drop, then consider the possibility that the coolant hoses were not correctly installed.
     
    #6 Patrick Wong, Oct 4, 2018
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  7. BlueOfLA

    BlueOfLA Junior Member

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    And the award goes to me, for being an idiot :D

    Thank you so much Patrick, you are an expert! I double checked the coolant hoses and I had the reservoir to the radiator, top of pump to inverter
    While it should be switched - reservoir to top of pump, inverter to radiator

    Very easy to switch these two by mistake since they are a similar location and tube size

    Also, Thank you exstudent for those links to Engine Loop and Inverter Loop
     
    #7 BlueOfLA, Oct 4, 2018
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  8. BlueOfLA

    BlueOfLA Junior Member

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    The inverter coolant filled nicely now that I swapped the tubes around.

    Because of the engine coolant however, I nearly ragequit the car tonight.. I just re-drained the coolant and I’ll try again tomorrow.

    I ran the CHS pump by force by shorting the relay and the radiator level wasn’t going down and the bleeder valve wasn’t showing any bubbles. The CHS pump sounded very loud. I tried starting the car (it starts right up after the new engine and trans which is a good sign) the CHS motor still sounded very loud. I don’t think I’ve heard it run that loud before ever draining the coolant. After 10-15 seconds the CHS pump stops and the car is idling. Turn the car off and the radiator level still does not drop. Pressing on the radiator hose for the engine I hear audible sloshing. I’ll have to check my hoses once more before continuing tomorrow.

    One major reason I concidered ragequitting the car - after all that extensive repair of P0AA6: 613 (Transaxle HV fault), when I ran the car to bleed the coolant I got a new error P00AA6: 612 (Battery HV fault). Aren’t I lucky!
     
    #8 BlueOfLA, Oct 5, 2018
  9. exstudent

    exstudent Senior Member

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    #9 exstudent, Oct 5, 2018
  10. BlueOfLA

    BlueOfLA Junior Member

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    Haha, I'd think you'd have to get a commission for the sale.
    Originally I thought it had a hand pump or something, but I would need to gift myself an air compressor too and the AirLift tool seems almost gimmicky or one-off for me personally because it wouldn't see much use
     
    #10 BlueOfLA, Oct 5, 2018
  11. exstudent

    exstudent Senior Member

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    You're speaking out of ignorance. You can look-up how/why the tool works; this is the reason why mechanics use it.

    See the simplicity and speed of coolant refills. No ragequitting here due to: stress/frustration/excessive time.

    Engine and Inverter refill by Carolyn at Luscious Garage.


    Engine refill by Contra Costa College.


    If you know people who are in construction or are very handy, home wise, one of them will have an air compressor.

    I don't make a living working on cars, so arguably the tool is excessive/overkill. But for me, the tool was not too cost prohibitive, to justify its acquisition. Also, already had an air compressor due to air tools.
     
    #11 exstudent, Oct 5, 2018
    Last edited: Oct 6, 2018
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  12. BlueOfLA

    BlueOfLA Junior Member

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    My mistake - I used the wrong word, by "gimmicky" I just meant for my personal use since I don't intend to use it often.

    I'm sure it's a fantastic product. I don't mean to knock it, the science behind it is sound to create a vacuum in the system to not allow any air when it's sucked up, and I have looked at videos in use (that's when I discovered it uses an air compressor). I believe even the Toyota dealerships use this device or similar when filling.

    It is nice to learn all the alternative ways it can be done. I managed to fill my radiator using some guides online and the help of you guys :D One of the biggest tips was to jack up the passenger side of the car as this seems to help push the bubbles through the system.
     
    #12 BlueOfLA, Oct 6, 2018
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