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Is the final "grunt" on stopping normal?

Discussion in 'Gen 5 Prius Main Forum' started by tovli, Nov 11, 2024 at 2:51 PM.

  1. tovli

    tovli 2023 Prius Prime replaced 09 Prius

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    Vehicle:
    2023 Prius Prime
    Model:
    XSE
    I have been coming to a stop in my 2023 Prius Prime XSE for 16 months the same as I did with my 2008 Prius: anticipate the stop by applying light braking, then a little more braking till rolling quite slowly (till regen braking is no longer the main force), then ease off the brake progressively while slowing further until the vehicle stops.

    In my 2023 Prius Prime XSE, all stops end with a quiet "grunt", that I did not often hear with my 2008 Prius.

    Is this final "grunt" normal in the 2023 Prius Prime?
     
    #1 tovli, Nov 11, 2024 at 2:51 PM
  2. kiwiscoot

    kiwiscoot Junior Member

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    My 2019 Prime does the same under the same scenario as you describe. That's normal. It is the cold brake pads on the rotors as the vehicle comes of regen braking and applies the cold brakes onto cold rotors. The kinetic energy is dissipated as sound instead of heat.
     
    #2 kiwiscoot, Nov 11, 2024 at 7:14 PM
    tovli and Trollbait like this.
  3. Gokhan

    Gokhan Senior Member

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    It is not. My 2021 Prius Prime Limited brakes are always whisper-quiet, and I didn’t hear brake noises when I test-drove a Gen 5 Prius XLE/XLE AWD. Gen 5’s stops are a lot smoother because of better brake modulation in the Toyota Hybrid System III (THS-III).
     
    #3 Gokhan, Nov 11, 2024 at 9:14 PM
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  4. kiwiscoot

    kiwiscoot Junior Member

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    does your Prius make "grunt" noises when you let the break go lightly so that the car starts crawling forward against the brakes and the lightly apply brakes again. My 2019 does and that is normal. Speaks of polished brake pads due to mostly regen braking and light braking. A few hard brakes from speed takes the polishing off the brake pads. Nothing that give me reason for concern.
     
    #4 kiwiscoot, Nov 11, 2024 at 10:37 PM
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  5. Gokhan

    Gokhan Senior Member

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    If you can hear any brake noise over the Prius pedestrian-warning sound, it is not good.

    And don’t try to fix your brakes by braking hard—it only makes it worse.
     
    #5 Gokhan, Nov 13, 2024 at 3:38 AM
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  6. kiwiscoot

    kiwiscoot Junior Member

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    No pedestrian-warning sound on our New Zealand models so we hear any little squeak on stopping in EV mode, even the regen braking cogging of the electric motors before the mechanical brakes take over on a slow stop.:)
     
    #6 kiwiscoot, Nov 13, 2024 at 3:02 PM
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