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Replaced Inverter Coolant Pump, Coolant not flowing.

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Zaden, Dec 10, 2023.

  1. Zaden

    Zaden New Member

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    Replaced the Inverter Coolant Pump in my 2005 Prius and the coolant in the reservoir is not moving. Checked the hose that goes into the top of pump and it isn't clogged, put it back on and still no movement in reservoir. Haven't drove it since new pump.

    Have had issues with the Prius for a while, have had it stall while driving, and wouldn't turn back on. No fuses blown and brand new coolant pump. Check engine light has been on for a while but turned off recently, haven't found out why it was on. Car turns on and runs now but I'm not going to drive it anywhere. New coolant pump also making very loud whining noise whenever the car is on. I've read other threads on similar problems and they say to either take out and clean Inverter hoses or replace the Inverter. So I'm hoping there is some other way I can fix this issue.
     
  2. TMR-JWAP

    TMR-JWAP Senior Member

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    If the inverter pump is loud, it is still air bound. You need to get the air out of the system.
     
  3. Tombukt2

    Tombukt2 Senior Member

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    Wow it's being loud and your reservoir is overfilled a little bit You need to be reaching down your hand to where the inverter pump is and squeezing on the hose like you're milking a cow then you'll see the fluid in the reservoir drop the noise will go away and your hand will tell you that coolant is moving then you need to drive the car because the whining stopped and the coolant is flowing and make sure you don't get the red car lit up on the multifunction display and/or the red triangle and the check engine light for the inverter pump code Make sure that you're inverter pump fuse is okay in the fuse box under the hood It must be because your pump is running and making noise milk the hose make sure it's full take it for a drive Best thing I can tell you.
     
  4. Zaden

    Zaden New Member

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    I tried to bleed the line while the pump was on and just a tad bit of coolant and some white crust came out, and nothing more.
     
  5. TMR-JWAP

    TMR-JWAP Senior Member

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    Connect a small (hopefully clear) tubing to the bleed connection and loosen it. Put the end of hose in the reservoir so all the fluid that comes out will go directly into the reservoir. Run the pump and start squeezing the hoses that go to it. You should start seeing fluid pass through the clear tubing.
     
  6. Tombukt2

    Tombukt2 Senior Member

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    So far the three or four that I've installed didn't need to be bled milked or anything else as soon as I turn the car on I hear the pump is on and usually within a few seconds coolant is being pulled through that pump I hear the noise go down and then I look at the reservoir The only time this didn't go like this is a time when I left the cap on the inverter reservoir and I kept wondering why is it taking so long and I didn't realize that the cap was still on that was the only time that the thing took minutes and the only reason that was is because I didn't realize the cap was on I was doing something else or watching something listening to something I don't remember but that went on for like 90 seconds I was like what the heck and then I looked over and saw the cap was on the reservoir The minute I undid the cap and lifted it up the pump got quiet and started to move coolant I don't really think running dry will affect this mag drive type of pump not too badly anyway
     
  7. Zaden

    Zaden New Member

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    I tried bleeding it again and now there is a big leak somewhere around the reservoir or inverter that I cannot get to, could it be that causing the noise?