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Radiator & invertor flushing

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sdhanapal, Dec 7, 2008.

  1. sdhanapal

    sdhanapal New Member

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    Can the radiator & invertor be flushed & refilled without purging the air ? I read several threads where some of them have refilled without using vaccum to purge the air out. I think the proper way is to using a vaccum device to suck all the air out of the system before filling with new fliud. this insures proper heating & cooling.

    Any thoughts?
     
  2. galaxee

    galaxee mostly benevolent

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    you can't flush in the traditional sense, just drain and fill.

    ABSOLUTELY NO VACUUM on the inverter, unless you want to replace it. that's what makes it so tricky. DH never used a vacuum tool on the engine coolant either out of precaution.
     
  3. hobbit

    hobbit Senior Member

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    In some of the tech-training seminars I was helping out with they
    were using an AirLift on the inverter circuit, at least on a
    Classic. Why not on the inverter loop, does it pull on the hoses
    too hard and let the barbs cut into them from inside?
    .
    _H*
     
  4. galaxee

    galaxee mostly benevolent

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    the inverter runs at something like 5psi, putting vaccum on that would crush it like a coke can. the vacuum tool DH has (and i'd presume most standard vacuum tools but he's not here to tell me that) are made for ~15psi systems.
     
  5. butchbs1985

    butchbs1985 Taking things apart is fun!

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    In another forum somewhere around PC, it was suggested that you just short the relay that runs the coolant pump to get the air out.

    I will state as that person did that I don't warranty this solution though. I don't remember the name of that thread but I'm sure you can find it.

    I did however short the relay with a paper clip when I drained my inverter coolant. No ill effects when I did it and it did get a lot of air out.
     
  6. direstraits71

    direstraits71 Member

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    This is a previously discussed issue, and one with conflicting opinions. These guys seem to have no problems using a vacuum tool:

    Art's Automotive - 30K Service, 2nd Generation Prius

    Maybe they have researched the max vacuum to apply and have some way of limiting their application of same. Guess you just have to make the call for your own vehicle.
     
  7. philmcneal

    philmcneal Taxi!

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    lol interesting device on the 2nd gen prius... airtool eh...
     
  8. Patrick Wong

    Patrick Wong DIY Enthusiast

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    Regarding the inverter coolant change, there's no need to short any relay terminals, as the coolant pump will run whenever the car is READY. The 2G inverter coolant loop is relatively easy to purge air out of (compared to Classic), and I see no need to use a vacuum tool.

    Regarding the engine coolant change, I previously had suggested shorting the CHS relay terminals at brief intervals to force the CHS pump to run and fill the CHS canister. Galaxee expressed concern about whether this would cause a problem with the valve that controls fluid flow to the canister. Therefore if you decide to use this approach, caution is required.
     
  9. jayman

    jayman Senior Member

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    The OP claims to have an '07 Prius. There is absolutely no need whatsoever to touch the cooling system that soon on a vehicle run on organic acid coolant technology.
     
  10. butchbs1985

    butchbs1985 Taking things apart is fun!

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    You're correct and that's what I used it for. Sorry for the misquote.
     
  11. richard schumacher

    richard schumacher shortbus driver

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    Yeah: why do you think it needs to be done?
     
  12. andyprius

    andyprius Senior Member

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    If you own a Prius, are not a techie, don't have a repair manual, this site is excellent!
     
  13. philmcneal

    philmcneal Taxi!

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    i asked a tech about changing coolant on a prius he tells me due to the cast aluminum design of the engine that somehow keeps the coolant very clean, also using toyota SUPER LONG LASTING COOLANT only makes that combo a better one. And to even add the icing on the cake the engine barely has a hard life! having the electric motors doing most of the grunt work for us!

    I'd be more worried about the battery than the engine at this point, engine is living the good life when it comes to the prius.
     
  14. Patrick Wong

    Patrick Wong DIY Enthusiast

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    I helped a local owner with 80K miles change coolant. The drained coolant was nice & clean, if poured into a punchbowl you would have no hesitation to drink it.
     
  15. paprius4030

    paprius4030 My first Prius

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    Even though the coolant is clean I'd be interested to know how the differnt additives in it hold up. Like the water pump lubricant ect. I was alwyas under the impression that that's a big reason to change the coolant. I regular car, when the coolant gets flushed and goes thru that machine, I was always under the impression that the machine readded the proper additives. I guess we can't do that with the Prius though, correct?
     
  16. sdhanapal

    sdhanapal New Member

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    Thanks for the feedback. I talked to the local dealer, they use it for convenience but it is not mandatory.