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Replacement ICE water pump (Aisin) going bad after only 50K miles

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by jadziasman, Feb 14, 2015.

  1. jadziasman

    jadziasman Prius owner emeritus

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    It seems that replacement parts made by the OEM manufacturer might not be built to the same quality level as those installed in new vehicles.

    Two and a half years ago, I replaced the ICE water pump in my 05. It was getting really noisy and I feared that the shaft bearings could seize at any moment. The original pump lasted 180K miles (not too bad).

    The replacement Aisin water pump I installed is making noise now after only 50K miles. The noise started about 5000 miles or so ago. I'm pretty sure I didn't starve the water pump of coolant when I installed it. I had no issues with trapped air during or after replacement. The pump ran flawlessly the first two years.

    The noise has not been as bad as the original was making but ideally the pump shouldn't make noise that you can hear when you're inside the vehicle. I've noticed that both of these water pumps have been very noisy in cold weather - after they began to make noise that is (cold to us northerners means well below 32°F - I'm soooooo jealous of those of you who live in more temperate climates). When temperatures are above 70°F, the replacement pump has been silent.

    I see no evidence that the pump has been leaking - that's good - one less thing to worry about.

    Looks like I might have to replace the pump again next spring or summer if the noise continues when milder temps eventually return to the Great White North. It's going to be really fricking cold here tonight -14°F is predicted!

    I might not use Aisin next time. Has anyone used a different brand? If so, how satisfied have you been with it?
     
  2. JC91006

    JC91006 Senior Member

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    Is the belt too tight?
     
  3. SageBrush

    SageBrush Senior Member

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    I put in Aisin, no problems
     
  4. jadziasman

    jadziasman Prius owner emeritus

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  5. JC91006

    JC91006 Senior Member

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    many oem pumps fail around 50k mark, leaks reported. I wouldn't be too shocked
     
  6. SageBrush

    SageBrush Senior Member

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    100k miles.
    Back in the day when the pump cost $50 - 75 USD I was happy to replace it as preventive maintenance every 50 - 100k miles at the same time I drained coolant. Now that they are much more expensive and I do partial coolant exchanges, I'll hope the pump lives a long life.
     
  7. wa-chiss

    wa-chiss Member

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    I see water pump leaks daily on our customer's Toyotas. Thankfully Aisin makes a fantastic transmission, because their water pumps are junk. I would say about 90% of the Aisin pumps we see leaking are from the weep holes. Very few have bearing failure. I would almost bet the belt tension was a bit tight. It's very easy to over tighten them on the Prius. Mainly because people like to loosen the pulley too far to allow it to slide up/down. They'll tighten the belt and then tighten the pulley nut. The belt will actually get tighter when that happens. A very small amount, but adding to an already tight belt doesn't help.
     
  8. bisco

    bisco cookie crumbler

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    thats why i don't like toyotas strain gauge requirement. it should be a deflection measurement.
     
  9. wa-chiss

    wa-chiss Member

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    Yeah, I've used the gauge so infrequently, I have no idea where it is in our cabinet at the shop.
     
  10. Den49

    Den49 Member

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    The water pumps failed prematurely on our previous 2007 Camry and 2005 Corolla. The Camry water pump failed first at about 36,000 miles, and was replace under warranty by Toyota, then again at 60,000 miles. The second time, I replaced it myself with a NAPA water pump with a lifetime warranty. The Corolla water pump failed at 47,000 miles and was replaced by Toyota, then failed again at 78,000 miles whereupon I installed a NAPA water pump with a lifetime warranty. I no longer have the Camry, but my daughter still has the Corolla which now has about 135,000 miles and the water pump is still good. Toyota's conventional water pumps are known for their high failure rate and seem to fail more in cold weather conditions. The NAPA water pumps have served me well.
     
  11. jadziasman

    jadziasman Prius owner emeritus

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    NAPA sells several brands. Were the pumps you bought manufactured by the Gates corporation? Part Number: 42253
    Product Line: NAPA Tru-Flow Water Pumps.
     
  12. brucebee

    brucebee Junior Member

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    havent worked on cars much lately but i have always ran my belts loose and havent had many probs. Been years but parts i bought from napa did seem more $, betgter quality ymmv
     
  13. SageBrush

    SageBrush Senior Member

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    IIRC the middle of the belt should depress about 0.5 inches with 20 pounds of pressure.

    I took the time some years ago to learn what 20 pounds of force is by pressing down on a weight scale with my thumb.
     
    #13 SageBrush, Feb 15, 2015
    Last edited: Feb 15, 2015
  14. jadziasman

    jadziasman Prius owner emeritus

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    A one square inch thumbprint is "king sized" to say the least.
     
  15. SageBrush

    SageBrush Senior Member

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    Correction: I learned what 20 pounds is, while pressing down with my thumb.
     
  16. Den49

    Den49 Member

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    The Corolla water pump was NAPA #TFW 41101, $48.59 + tax, purchased and installed in March 2011. Description is: "These O.E. Equivalent Water Pumps have a unitized seal to protect the bearings & provide leak-free, long-life performance. The 1-piece bearing assembly has factory sealed bearings that are computer matched for low friction. N0-sealant-required gaskets." The "limited lifetime warranty" refers to Gates Corporation, Denver, CO as the manufacturer and warrantor.