Problem using Airlift to pull vacuum

Discussion in 'Gen 3 Prius Main Forum' started by Bob the occasional mech, Aug 21, 2025.

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  1. Bob the occasional mech

    Bob the occasional mech New Member

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    I replaced the water pump on my wife's 2010 Prius, and now I'm all set to refill the cooling system. I purchased an Airlift vacuum system to speed up the refill and help eliminate air bubbles. The coolant tank refill neck narrows to a very small opening just past the mouth of the neck, which prevents me pushing the funnel shaped Airlift adapter far enough into the neck to get a good seal without the adapter moving around. But I found if I combined the funnel adapter with one of the other smaller adapters, I could get what looks like a decent seal, and is reasonably stable.

    So, with the Venturi valve secured to the Airlift body, and air hose attached, and overflow tube and bottle ready, it looks ready to go. I turn on the air and I hear a high pitched whine of air movement through the Venturi valve (which I think is normal when the Airlift valve is still closed), I open the valve, but no vacuum develops. The only noise is air flowing into the overflow bottle (but now without the whine). :-(

    I have a feeling I'm forgetting something, but I can't figure out what. I double-checked the radiator drain cock to be sure it's closed tight. I suppose the Airlift may not have a good enough seal to the tank, but it looks good enough to least draw a slight vacuum. It's almost like the Venturi valve is broke, but I doubt that since it probably has no moving parts. I double-checked the Airlift body valve to ensure it appears to be opening and closing properly. It looks like the water pump is well mated to the engine all the way around.

    Any ideas about what I might be doing wrong? Does anyone have a good tip on how to get a good, stable seal between the Airlift body and the tank?
     
    #1 Bob the occasional mech, Aug 21, 2025
  2. Mendel Leisk

    Mendel Leisk MMX GEN III

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    I’ve used the method proscribed in repair manual, no special equipment needed, and went pretty smooth.

    I wouldn’t bother with the engine block drain btw, I’d heard it was a waste of time, had to find out for myself, think I got 1/2 cup, at most.
     

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    #2 Mendel Leisk, Aug 21, 2025
  3. Georgina Rudkus

    Georgina Rudkus Senior Member

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    I had no problem with the UView airlift and have used it twice with my Gen 3 Prius v.

    I used only the little rubber tip and no other rubber adapter.

    It worked just fine and made a good seal.
     
    #3 Georgina Rudkus, Aug 21, 2025
  4. Tombukt2

    Tombukt2 Senior Member

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    Heck I never had a problem filling 3 it's the 2 that's at issue. Water slam rt onto a 3 pretty quick
     
    #4 Tombukt2, Aug 21, 2025
  5. ASRDogman

    ASRDogman Senior Member

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    If you fill it very slowly, a small amount at a time, you won't have air bubbles.
    The slowly filling coolant will force out the air....
     
    #5 ASRDogman, Aug 21, 2025
  6. Georgina Rudkus

    Georgina Rudkus Senior Member

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    Only problem was the hard set in the coiled vinyl hoses.

    The intake would spring off the bottom of the container and start suckling air ruining the procedure.

    I finally replaced them with super flexible silicone hoses.
     
    #6 Georgina Rudkus, Aug 21, 2025
  7. ChapmanF

    ChapmanF Senior Member

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    There aren't many typos that can change a meaning more completely than prescribed / proscribed. Using the proscribed method, you rebel, you!

    My experience also. Using the prescribed method Just Works. The gen 3 degas-bottle system ships any trapped air back to the bottle where it trades places with the extra coolant between the FULL and B line, leaving the level at FULL.
     
    #7 ChapmanF, Aug 22, 2025
    Last edited: Aug 22, 2025
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  8. Mendel Leisk

    Mendel Leisk MMX GEN III

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    Huh, I have been blissfully unaware of the difference, thanks.

    IMG_1479.jpeg
     
    #8 Mendel Leisk, Aug 22, 2025
  9. Tombukt2

    Tombukt2 Senior Member

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    I try not to use in big words like mayonnaise.
     
    #9 Tombukt2, Aug 22, 2025
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  10. Bob the occasional mech

    Bob the occasional mech New Member

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    Thanks, Georgina, that solved the problem! I wasn't sure what that small piece was for since it didn't look or fit the same way as the other adapters, but after seeing your reply, I finally realized it does indeed attach to the Airlift body and creates a good seal. It's amazing to see how fast and easy it makes refilling the coolant!

    Thank you, everyone, for your responses!
     
    #10 Bob the occasional mech, Aug 22, 2025
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