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Loud squeal while braking to a stop -- video attached

Discussion in 'Model S: Driving Dynamics' started by Ed Chan, Nov 24, 2014.

  1. Ed Chan

    Ed Chan Member

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    #1 Ed Chan, Nov 24, 2014
    Last edited by a moderator: Mar 13, 2016
    I recently had my brake booster replaced in my autopilot-able S85, as requested by Tesla. Since then, every once in a while (so far 3 times in 2 weeks) I've had this strange noise when braking close to a stop, and a very high frequency vibration coming from my steering column as well. Any ideas? I'll probably bring it in after the holiday for them to look at...

     
  2. AnOutsider

    AnOutsider S532 # XS27

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    Any lights or warnings? Could the car have thought you were coming close to colliding? Or perhaps it's detecting the red light as part of some future SW enhancement and it's mistakenly activated in yours haha. Either way, sounds like something is up with one of the AP sensors (or software)
     
  3. Ed Chan

    Ed Chan Member

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    Just for clarification, it's definitely a mechanical sound, not a computer generated one...
     
  4. AnOutsider

    AnOutsider S532 # XS27

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    Ah, OK. Sounded like it came from the system in the video.
     
  5. PlanB

    PlanB Banned

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    Next time you might want to turn the radio down. Also, that is not abnormal my car does it as well, it's the new bigger brakes and the dry pads. Mine does it when it's hot and dry out.....sometimes when it's rains but not as bad.
     
  6. Todd Burch

    Todd Burch Electron Pilot

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    What new bigger brakes? I have a recent build (P85) with over 2,000 miles on it and I've never heard that sound. 35,000 miles on an early Tesla and never heard it either. That is absolutely not normal.

    Sounds like the rotor is vibrating (also explaining the slight vibration in the steering wheel)...should be fixable.
     
  7. scottm

    scottm Active Member

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    I get brake squeal that sorta sounds like that at slow stops.

    remember, brakes are for inefficient drivers, regen rules!

    That sound is my penalty reminder that I should not be using brakes.
     
  8. Ed Chan

    Ed Chan Member

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    I don't think it's normal.. It was VERY VERY loud, and like I said before, it made the steering column vibrate... My service advisor noticed my post and contacted me and they'll take a look at it after thanksgiving, since i'm skipping town on wednesday.

    @scottm - Regen can't bring your car to a stop, so unfortunately, brakes are still required :)
     
  9. Kbsilver

    Kbsilver Member

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    That sounds like typical brake squeal, essentially the brake pad vibrating at a high frequency during braking. It is often necessary to apply an anti-squeal compound to the back of the brake pads to stop this. Whenever I replace pads I either use the compound supplied with the pads or apply high temperature anti-seize grease/compound to all the metal to metal contact points of the brake pad. I've never had a squealer using this method.
     
  10. rdrcrmatt

    rdrcrmatt Member

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    Bike brakes squeal as well, but usually a higher pitch than that. the resonance frequency of your wheel, brake rotor / pad combo must be different than my car (P11xxx - P85, 19").

    Most of the squeal we get is due to the lack of use of our brakes.
     
  11. linkster

    linkster Member

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    #12 linkster, Nov 25, 2014
    Last edited: Nov 25, 2014
    You may consider performing a quick visual check just to insure that the plastic anti-squeak shims (two/caliper) did not get missed during the Brembo assembly procedure that can be verified without wheel removal. They are located by the brake pad cross pins along with several clips (two of which can be easily seen at the top of the caliper). The top clips/tabs are inside the pins on the front calipers and outside the pins on rear calipers and fit snugly between caliper pistons and brake pad metal backing plate.
     

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  12. ArtInCT

    ArtInCT Always Learning

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    #13 ArtInCT, Nov 26, 2014
    Last edited: Nov 26, 2014
    If the noise pops up just before your vehicle comes to a complete stop (as it did in your video), as opposed tosquealing throughout the entire range of braking, the cause could be a brake pad that is vibrating against the rotor. A set of brake pad vibration damper pads /shims / lubrication could cure the squeal, but there's no guarantee. Also some brake assemblies have a wire spring on each pad that tries to pull the pad away from the rotor when the brakes are not used. These springs can be missing or not attached correctly due to recent work done on the car or some other mishap. If the springs / shims are wrong, your pads could have been rubbing slightly on the rotor and perhaps have become glazed. Glazing on the pads can cause the squeal and vibration when applied. Glad you got an appointment and will be getting them looked into by your SC.

    Another cause of squeal is a wear indicator that is inbeded in the break pad itself. As the pad wears out it reveals a metal tab which emits a very loud squeal as it rubs against the rotating rotor. I do not think this is the case in your instance as the squeal was more towards the end of the stop.

    Also, if you get new break pads as a part of the fix, do some research on breaking in new pads. There is a procedure to mate the pads to the rotors which is easy and somewhat fun.
     

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