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How to Replace the Inverter Coolant Pump

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by Patrick Wong, Jul 12, 2009.

  1. 2004priusgal

    2004priusgal Junior Member

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    great reveiw. May 2021, 2004 pri 182k.
    we are changing pump again after just 3 years. in NJ its hot but not that hot...
    could there be another reason why pump failed... ?
    Are there other temp sensors etc we should check?

    A week before the only thing i did was clean the headlamp near the pump which involved electric sanding and spray acrylic....

    All fluids were changed by dealer last year... thx for enthusiasm
     
  2. 3dmacs

    3dmacs MAC aboard!

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  3. 3dmacs

    3dmacs MAC aboard!

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    Patrick
    Thanks my guru of Prius. This spring have replaced the traction battery @ 115K on my wife's 2006 Prius. Also the Die Hard is new in June. Traction battery replacement Work was performed by Green Man Battery out of Raleigh NC. Unfortunately the Inverter Pump was not replaced under Toyota recall and I'm suspecting the car may have also been in a front ender and may have had the fans removed and replaced in reverse. Thus your comment about this disrupting the cooling flow to the engine and inverter.
    Question 1 : How do I determine the fans are installed properly.? do they suck or blow into the underhood area
    Question 2.: My OBD2 handheld is old and doesn't give me Prius Hybrid info or codes. It does seem however to clear codes and resets the triangle of death/brake/check engine/vsc dash lights and does reset the dash ready light. I need to provide hybrid codes to green man so they will know whether or not to come out replace my Refurbished Traction battery.
    Question 3: Please recommend a cheap but functional Prius Hybrid OBD handheld so I can move on and any other ideas which you might discern.
    Many thanks in advance.
    Dave Mclintock
     
  4. ChapmanF

    ChapmanF Senior Member

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    Question 1: they definitely pull air from in front of the car, in through the grille, through the condenser, through the radiator, past the fans, and into the engine bay. Or they darned well should, anyway.

    It does seem to be easy to mess them up on reassembly, by not noticing which way they rotate and which blade goes where. It's funny, a thread on the same topic but for Gen 3 has been active just today. That gives the Gen 3 details.

    I am not positive of the details for Gen 2, but from the diagram they appear to be the same, right down to the two fans having different blade counts.

    [​IMG]
     
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  5. Mendel Leisk

    Mendel Leisk Senior Member

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    You’d think the engineers would have the presence of mind to ensure they can’t be mixed up? Say the fans swapped or flipped. Maybe not so much?
     
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  6. ChapmanF

    ChapmanF Senior Member

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    I'm not completely sure that isn't the reason they have different blade counts: so you can tell they're different, and see which goes where right in the diagram.
     
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  7. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Question 3: I use Toyota Techstream cloned software (Mini VCI) running on a Windows 7 laptop dedicated to that purpose, and do not have recommendations for a handheld device.
     
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  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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  9. AlohaSpirit

    AlohaSpirit Junior Member

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    Replaced my last pump at a private shop. Dont remember what they charged but I dont believe it was too bad.

    After 40k miles, it went out so I decided to do it myself.

    I bought a used OEM and it took about 1.5 hours for install by going through the headlight. (Could probably do in an hour)

    Hardest thing was working in the mid-day sun.

    Barely lost coolant (blocked bottom hose first) and also used a 1/4" inner diameter hose to bleed the system too.

    I highly recommend everyone DIY this when its your time to replace.
     
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  10. Ultimate_Combination

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    Thanks for this DIY post @Patrick Wong
    I experienced my first dashboard light-up this warm afternoon @ 70mph on the way to get some Costco gas w/ my son in the back in my Mom's 2008 w 147k

    The code reader I have in the glovebox couldn't read the code, but the Amazon RPM OBDII Gauge I had from my old Turd Gen could read the code, the P0A93..with this being one of the most relevant posts.

    I just ordered my G9020-47031 from Fred Anderson Online for $90 and will aim to pick it up locally, and get this done sometime later this week :p
     
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  11. Joey40202

    Joey40202 Junior Member

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    Thank you Patrick for the detailed instructions. Here are a few photos of the inverter water pump that I removed after a my pump failed a few weekends back. I wanted to know what made it tick so I tore it apart and it appears to be a electronic control board and a magnetic turbine pump wheel which that creates the coolant motion. In my cause I lost movement in the reservoir tank, got the triangle of death etc so I purchase a new OEM part from Toyota. Also, the photos show a genuine Toyota part that was replaced under recall which failed at a guesstimate of 8 years later. The inverter pump seems to be thermally sealed plastic with no serviceable parts so I cut it open. In my cause the pump turbine still spun freely but my guess is that something on the electronic control boar which is built and sealed into the base of the pump failed. Just my guess and I could be wrong.
     

    Attached Files:

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  12. Patrick Wong

    Patrick Wong DIY Enthusiast

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    My daughter's 2007 has logged 158K miles. In 2011 when the car had 30K miles, the inverter coolant pump was changed under recall (and the engine coolant heat storage pump also was changed under warranty because it was noisy.)

    Now that 11 years and 128K miles have passed, the inverter coolant pump is still working (amazingly) but the circulation visible in the coolant reservoir was minimal, so I replaced the pump today. The price of the pump, 04000-32528, was $92.72 plus shipping from Lakeland Toyota (toyotapartsoverstock.com).

    Since I started this thread 13 years ago, many posters have contributed their methods and experience, which I appreciate.

    Some posters like to remove the headlamp assembly for access to the pump. My method is to remove the nearby inverter mounting bracket, remove the inverter coolant pump from its sheet metal base, then remove the base from the body. The pump can be removed through the gap between the front of the inverter and the radiator bulkhead.

    After doing that job, I decided I needed to buy more Toyota Super Long Life Coolant, so I went to a local dealer. The price today was $34.99/gallon, an amazingly high price considering it is 50% water. The last time I bought SLLC was in 2017, at that time the price was $21.65/gallon. I noticed the current amazon.com price is $33.52/gallon, next time I'll just buy online.
     
  13. alftoy

    alftoy Senior Member

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    Aisin SLLC from Rockauto $14/gal. Shipping is $8.99 if you buy 2.

    Aisin Aftermarket

    AISIN Seiki Co. Ltd., was founded in 1965 as an OE manufacturer. Approximately 24% of its ownership is retained by Toyota today
     

    Attached Files:

    #232 alftoy, Jul 29, 2022
    Last edited: Jul 29, 2022
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  14. mr_guy_mann

    mr_guy_mann Senior Member

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    Yep. Flip a coin. Heads - something on the circuit board fails open so the pump stops and you get a P0A93 overheat code. Tails - something on the board shorts and blows the AM2 fuse which kills the car.

    Just happen to have a 08 come in late Friday- dead pump and P0A93. Pump's on order for Monday.

    Posted via the PriusChat mobile app.
     
  15. aleyoop

    aleyoop Junior Member

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    When bleeding the inverter....is the car on or off? Instructions seem to say the car should be off?
     
  16. ForAMorePerfectCommute

    ForAMorePerfectCommute Junior Member

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    Does it matter, so long as the pump is running?

    I did this job a few months ago and I didn't lose much coolant so I didn't do any formal bleeding procedure.
     
  17. ChapmanF

    ChapmanF Senior Member

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    It does help to know the names of the different modes the car can be in, so posts in a public forum won't be confusing.

    The car can be in OFF, ACC, ON, or READY. The pump will not run in OFF or ACC. So that leaves ON or READY. The manual suggests ON, not READY, so you can get all the air out of the inverter cooling loop before you start asking the inverter to do stuff.
     
  18. aleyoop

    aleyoop Junior Member

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    on is activated by pressing the button twice without pressing the gas pedal?
     
  19. Mendel Leisk

    Mendel Leisk Senior Member

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  20. aleyoop

    aleyoop Junior Member

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    So i got it done...took around 1.5 hours. One thing which concerned me was that even after tightening the 3 bolts on the pump body...there is still a bit of wiggle room. Is this normal? Basically the pump body can move around a bit and there was no way to snug it down (actually broke one of the bolts trying to do this lol)....

    Any ideas?
     
  21. ChapmanF

    ChapmanF Senior Member

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    The pump vibrates. The mountings are rubber and loose enough on the bracket to avoid transmitting the vibration into the body of the car. When you tighten the bolts down, they tighten only on the bushings inside the rubber mounts. That's all by design.

    You'd be surprised how much difference that makes to the sound. I picked up a rebuilt Prius once where the pump had been attached so tightly the rubber mounts couldn't do their job, and sitting in the cabin sounded like being trapped in some industrial machine. All because of that little pump, but with its sound carried straight into the body steel.