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Inverter coolant pump.. pump running but not flowing.

Discussion in 'Gen 2 Prius Technical Discussion' started by Tynyyn, Aug 11, 2022.

  1. Tynyyn

    Tynyyn Member

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    Just replaced my inverter coolant pump and filled up the coolant tank with red coolant and then ran the engine. The pump was running but the coolant was not circulating. I drove the Prius for an hour and turned it off. Popped the hood, turned the ignition on and unscrewed the coolant tank lid and found the color of the coolant had changed to a rust color and the coolant was not circulating.. This makes me wonder if I have a restriction within the lines of the coolant system. One that prohibits the flow. I've looked through a few pages within the search feature and haven't read anything about a restriction in the inverter coolant system.

    Any suggestions?
     
  2. ChapmanF

    ChapmanF Senior Member

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    The most recent such story here ended with finding a bolt inside one of the hoses, but I'm guessing usually the blockage will be something else, like the goop that forms from corroded aluminum.
     
  3. Tynyyn

    Tynyyn Member

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    Now it makes me wonder how to clean out the system. Put a garden hose into one of the coolant lines an turn on the garden hose valve? Or is there a more technical way of doing the flush?
     
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  4. Tombukt2

    Tombukt2 Senior Member

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    That's the way we always did it prestone used to make a t that put a garden hose fitting right in your cooling line the proper cooling line and when you hook the garden hose to that and just cracked it open you didn't have to blast it like crazy but you could once or twice and you could see the stuff come flying out the hose you leave open so you put the tea high up where it runs through the whole system and then like you undo the output on the on the heater core and let it rip
     
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  5. PriusCamper

    PriusCamper Senior Member

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    There's nothing in the system that's going to turn your coolant to rust colored, therefore more than likely nothing in the system that needs to be "flushed" out. Are you sure you used to correct antifreeze and didn't have something go wrong with the labels of what what was stored in your garage?

    As for the lack of turbulence, I'm voting on bad inverter cooling pump. The cheapest pumps that cost like $27 sometimes fail in the first few days or weeks after installation so you gotta be prepared for putting more than one in sometimes if you want to save money on parts. Try plugging it and unplugging it with car on, sometimes that shocks the motor back to life again.
     
  6. Tombukt2

    Tombukt2 Senior Member

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    Yes I can tell you the cheap pumps don't run long at all I've been through several in 2 years on the 2009 that's daily driven everyday I gave up on them I didn't want to spend the hundred plus on a Toyota one to have it possibly go bad because I can't imagine there's very many factories in China or wherever making these types of pumps the lower volume coolant type pumps for the automotive industry so these cheapo ones are second or thirds or ones at Asian and won't take whatever. So I used a different pump all together the one that goes in between the brake accumulator it's a 14.4 volt looks like a little mini spa pump I put that down where my inverter coolant pump used to be and haven't had a problem since I'm waiting.
     
  7. PriusCamper

    PriusCamper Senior Member

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    Wow, that's what I was hoping someone would try doing... These pumps are such a small amount of gallons per minute that you could probably find higher quality in parts in a different product line.

    Do you have a link to pump you bought?
     
  8. PriusCamper

    PriusCamper Senior Member

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    Something like this might be an interesting alternative to experiment with, especially if lowering the voltage to it would allow you to adjust rate of flow. The main challenge of course is lo-flow electric water pumps are rarely designed to work up at 180' F. for very long.

    Solar DC 12V Hot Water Circulation Pump Brushless Motor Water Pump

     
    #8 PriusCamper, Aug 11, 2022
    Last edited: Aug 11, 2022
  9. pasadena_commut

    pasadena_commut Senior Member

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    Perhaps the pump is working fine, it has not overheated, right? If you can drive the car on the highway for more than 10 minutes on a hot day without the dash lighting up then the inverter cooling circuit is working.

    The last OEM pump I put in barely roils the tank, the light and angle have to be just right to see it, yet it clearly works since the inverter never overheats. (The warning lights have not come on, and I checked the temperature once with techstream after driving on the highway for a while, and the inverter was not very hot. ) I'm not sure how to explain this. It could be the pump rate is lower than some other pumps, or maybe some of the turbulence people see is due to variation in the flow rate at the pump manifesting in the tank, but a new, smooth pump doesn't do that as much.

    For whatever its worth, the Dorman pump that was in before this one really stirred up the tank. Unfortunately sometimes it wouldn't start when the car did and the inverter would overheat. So a roiling tank is not the be all and end all of pump functionality.
     
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  10. ChapmanF

    ChapmanF Senior Member

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    Right, the metal parts in this system are aluminum, not steel, so if the coolant goes too long between changes, the anticorrosives in it get depleted, and the aluminum oxidizes, it isn't the color of rust.

    Soggy aluminum oxide is more of a kind of blobby whitish-gray jelly.

    [​IMG]

    [​IMG]
     
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  11. pasadena_commut

    pasadena_commut Senior Member

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    Do we really know the chemical composition of that stuff? Could it be something more complex involving both metal from the case and chemicals in the coolant? Or aluminum hydroxide or some other related compound - those are at least very slightly soluble in water, so they might form a gel with it. Water should just run off of pure aluminum oxide (like corundum).

    In any case, aluminum oxide is pretty much insoluble in everything one might want to pour through the inverter. It would have to be removed mechanically, perhaps with a lot of water pressure and flow to break up those clumps and push it out, or more likely, open the device up and scrub it out.
     
  12. PriusCamper

    PriusCamper Senior Member

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    That'd be a great name for our new PriusChat houseband!

    We're debuting our first CD and traveling the world in Priuses with that name now thanks to you!

    And free nexcell packs to first 200 people to show up at all our shows!
     
  13. rjparker

    rjparker Tu Humilde Sirviente

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    If it is actually a white slime gunk, a very similar bacteria grows in many southern hvac condensate pans and lines. Especially now as most manufacturers have gone to aluminum coils.

    Perhaps the use of the wrong coolant or straight tap water for top offs is doing something similar in the inverter. The inverter loop is low pressure and normally the inverter does not get as hot as the engine coolant.

    EEB5EFFC-D94F-4476-93A1-176DE685D2E4.jpeg
     
  14. Tynyyn

    Tynyyn Member

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    How do you clear the warning lights (brake light and (!) light) on the dash? Unplug the 12v battery? This car has been great for the past ten years, but now I'm thinking the gremlins are hard at work trying to tear it apart from the inside out.
     
  15. ChapmanF

    ChapmanF Senior Member

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    Yeah, the exact chemical process I should probably leave to be described by someone like a chemist. :)

    What I can say is when I changed out the old aluminum anode rod in my house's water heater, the same some really similar blobby gel stuff was on it. After leaning against the wall for a long time to dry, it was whitish and powdery. A bunch of stuff also ends up at the bottom of the tank and has to be flushed out. After long enough to dry, it looks like some sort of breakfast flakes.

    There are more chemical possibilities there because of course the city water has minerals and some iron content that you don't expect in the car's distilled water and coolant.

    When I changed the anode rod, I replaced the aluminum one with a resistored magnesium one. That was around a decade ago and I should probably be checking on it soon. I'm already pretty sure it sheds less goop, because by this long with the aluminum one, I could already hear steam pockets popping through the goop at the bottom when the burner was on, and it's not making those kinds of noises now.
     
  16. mr_guy_mann

    mr_guy_mann Senior Member

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    Did you bleed the cooling system using the bleeder in front of the inverter? If I drain the system (to flush the white stuff out with water), l have to bleed for awhile.

    I put a small hose (1/4" by a few feet long) on the bleeder and hold the end in the tank opening. Turn the ignition on and open the bleeder. It can take 5 minutes or more to stop pushing air bubbles out- topping up coolant as needed.

    The pump should push a decent stream out of your bleed hose. You don't NEED to use a hose, but it's less messy if you do.


    Posted via the PriusChat mobile app.
     
  17. edthefox5

    edthefox5 Senior Member

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    Many posts on clogged inverter channels. Probably high mileage car and inverter coolant never changed. Aluminum in solution is very corrosive.

    If it was me I would remove the hoses on the pump and measure there inside diameter. Go to lowes or Home d and buy a pex barrel with that od.
    The you can connect the 2 hoses together using that barrel bypassing the pump.

    open bottom dump bolt and with garden hose in the reservoir try giving it a good flush.

    Senn a few here that the buyer found last owner used yellow dex cool and that really clogged it up.

    If hopelessly clogged the entire inverter must be replaced as the aluminum coolant Chanel radiator is part of the inverter.

    Good luck.
     
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  18. PriusCamper

    PriusCamper Senior Member

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    The images aren't related to the problem OP posted about in the thread... They are just posted to help explain that this cooling system consists of aluminum, plastic and hoses and there's nothing in the system that can turn the coolant rust colored so I'm thinking there was a mix up with what was put into the vehicle when the inverter pump was replaced.
     
  19. PriusCamper

    PriusCamper Senior Member

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    Wow... You're like the only person I know that knows what water heater maintenance is...
     
  20. ChapmanF

    ChapmanF Senior Member

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    Who likes replacing water heaters?