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Whirring electrical sound (at startup) getting frequent

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by alokeprasad, Apr 4, 2016.

  1. alokeprasad

    alokeprasad Member

    Joined:
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    Location:
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    Vehicle:
    2010 Prius
    Model:
    III
    On my 2010 Prius (~75,000 miles): The whirring electric motor sound that one hears when just entering the vehicle (even before starting the vehicle) seems to be getting more frequent (and maybe louder).

    I used to notice it only when getting in the car and before or just after pushing in the start button. But now I notice it driving around the neighborhood, even at moderate speeds.

    Is this a sign of some impending failure?

    Thanks.
    Aloke
     
    #1 alokeprasad, Apr 4, 2016
  2. bisco

    bisco cookie crumbler

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    that's your brake accumulator tank. it would be unusual to fail this early, but certainly possible. maybe your hearing has improved?:)
     
    #2 bisco, Apr 4, 2016
  3. David Beale

    David Beale Senior Member

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    It's the brake pressure pump bringing the brake system up to pressure (getting the car ready for you to drive). It's possible over time it will run longer to begin with. The brake system always leaks some fluid past the seals (usually in the master cylinder) and that should increase with age and use. I don't think it has anything to do with "impending failure". Pearl S has always run much more than Pearl ever did. The Prius doesn't use vacuum for brake boost because the engine can shut off at any time, so instead it uses an electric brake fluid pump and an accumulator reservoir.
     
    #3 David Beale, Apr 4, 2016
  4. Former Member 68813

    Former Member 68813 Senior Member

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    Well, maybe it's nothing, but I would start looking for cheap used part on eBay. These things are known to fail and are expensive at a dealer.
     
    #4 Former Member 68813, Apr 4, 2016
  5. RRxing

    RRxing Senior Member

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    Did you have the brake accumulator recall done?
     
    #5 RRxing, Apr 5, 2016
    Mendel Leisk likes this.
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