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Weird grinding noise at hard braking

Discussion in 'Model S: Driving Dynamics' started by hanl1, Oct 18, 2015.

  1. hanl1

    hanl1 Member

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    So last night while driving I had to hit the brake really hard when the car in front had a sudden stop. At the end of the braking I was hitting the brake really hard and I felt what I would describe as a rock grinding noise coming from the bottom of my car. The noise went away after I lifted the brake and it didn't come back under normal braking.
    Anyone knows if this is normal? Could be a noob question but maybe that was the ABS?
     
  2. thegruf

    thegruf Member

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    stone caught in the brake caliper?
     
  3. Evbwcaer

    Evbwcaer Member

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    Did you just start driving? Was it, or had it been, raining? My thought is rusty rotors that the hard braking rubbed off.
     
  4. woof

    woof Model S #P683 Blue 85 kWh

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    Probably ABS. Try a practice "panic stop" situation in a safe location (empty parking lot for example). It's always good to get a feel for where ABS kicks in.
     
  5. Lyon

    Lyon 2016 S P100DL, 2016 X P90D

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    ABS makes a noticeable shuddering/pulsing/grinding noise as the calipers pulse to prevent lockup. That's probably it.
     
  6. tstafford

    tstafford Member

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    I second this.
     
  7. Xenius

    Xenius Member

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    Third, was weird as hell the first time I ever felt ABS kick in, but it's repeatable and you'll get used to it (but hopefully not too used to it).
     
  8. hanl1

    hanl1 Member

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    I guess I will go with the more re-assuring ABS theory :) Thanks folks
     
  9. brkaus

    brkaus Member

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    When ABS was a new thing, it was common advice to go to a safe area and stomp the pedal. It is a strange sensation and probably worth trying so one doesn't panic in a real emergency b

    I don't trigger it much on my bmw, but my diesel truck triggers more easily. I'm suspecting the greater weight of the truck makes stopping harder and hence ABS gets used more. The model s weighs nearly the same as my truck.
     
  10. patrick42h

    patrick42h Member

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    Most, if not all, cars have a metal tab that drags on the brake rotors when the pads get too thin. Maybe that is what you are hearing.
     
  11. thegruf

    thegruf Member

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    ^ that will usually get you a hideous squeal not a grinding noise.

    abs is typically more like a vibration than a grinding noise
     

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