Help - what are these noises?

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by Robinhaleyb, Jan 29, 2025 at 8:38 PM.

  1. Robinhaleyb

    Robinhaleyb New Member

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    I drive a 2013 Prius with 75,000 miles. Hearing some weird noises - please see video above for reference.

    1. Hissing while hitting the brakes, and
    2. Loud humming noise happening every 10-15 seconds when car is on, and for about 3 minutes after turning the car off.
    What could this be? Thank you!
     
    #1 Robinhaleyb, Jan 29, 2025 at 8:38 PM
  2. Grit

    Grit Senior Member

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    Could be a bad brake accumulator. What level is the brake fluid level at? When was the last time brake fluid was changed?
     
    #2 Grit, Jan 30, 2025 at 11:37 PM
  3. Brian1954

    Brian1954 Senior Member

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    The sound you recorded is the pump used to pressurize the brake fluid. If the pump turns on too frequently without stepping on the brake pedal, then you have a problem (usually an internal brake fluid leak in the brake actuator). Eventually, warning light will appear on the dash, and then you have a very expensive repair to fix the problem.

    Do you have any warning lights on the dash.
     
    #3 Brian1954, Jan 31, 2025 at 1:16 AM
  4. Grit

    Grit Senior Member

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    Because saving gas cost a lot of money.
     
    #4 Grit, Jan 31, 2025 at 11:56 PM
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