Water pump/pulley rattle and wobble

Discussion in 'Gen 2 Prius Care, Maintenance and Troubleshooting' started by sciencekit, Sep 26, 2011.

  1. sciencekit

    sciencekit Junior Member

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    Well, I heard a rattle coming from the idler pulley area last week, so I just finished replacing that along with a new belt in my 2004 Prius. Just for grins while the belt was removed, I reached down to give the water pump pulley a spin. The pulley wobbles and slightly rattles under hand spinning... feels "loose". This must be the real culprit since when I tightened the new idler pulley/belt, started the Prius, and "drum roll please"... yup, the rattle is still there.

    Question is, do I replace the water pump or just try to find a pulley for it? My spider senses say "replace the pump", as the pulley just seems to bolt to the pump with no real bearing visible. Is it difficult to replace the pump?
     
    #1 sciencekit, Sep 26, 2011
  2. Patrick Wong

    Patrick Wong DIY Enthusiast

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    You need to replace the engine coolant pump as the bearing is worn and cannot be economically replaced. It is no more difficult to replace that pump than on a conventional engine.

    However the difficulty will come when you are trying to get air out of the system, especially when trying to refill the coolant heat recovery system canister. I have posted on how to do that without needing special tools, which involves shorting two contacts in the CHRS relay socket with a paper clip to force the CHRS pump to run.
     
    #2 Patrick Wong, Sep 26, 2011
  3. sciencekit

    sciencekit Junior Member

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    Thank you, Patrick. Do you know of a site where I can obtain the engine coolant pump replacement instructions? If one exits. Even just a diagram that might show the steps would be fantastic. I have yet to replace a coolant pump on any vehicle. This is the first toyota I have owned where it failed. After 485,000 miles on my 1990 4Runner, even it still has the original coolant pump. Also, do I need any special tools?

    What do I need to search for to find your system bleeding instructions?

    Thank you for your help.
     
    #3 sciencekit, Sep 27, 2011
  4. Patrick Wong

    Patrick Wong DIY Enthusiast

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    See my posts #22 and 42 here:
    http://priuschat.com/forums/gen-ii-...shooting/30813-changing-engine-coolant-5.html

    Regarding engine coolant pump replacement instructions, you can download repair manual info at techinfo.toyota.com

    Regarding special tools, if you have a decent set of metric sockets and open/box wrenches that may be sufficient. Try loosening the pulley bolts before removing the serpentine drive belt, that may avoid the need for a special tool used to hold the pulley in place.
     
    #4 Patrick Wong, Sep 27, 2011
  5. sciencekit

    sciencekit Junior Member

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    Again Patrick, your knowledge is fully appreciated. Wish me luck, as I will tackle this tomorrow. *fingers crossed*
     
    #5 sciencekit, Sep 27, 2011
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