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My brakes are vibrating, and it's not the good kind :(

Discussion in 'A3/S3/Sportback (8P Chassis)' started by boggysv, Aug 19, 2009.

  1. boggysv
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    boggysv Member

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    Think it's caused by my last trackday (10th aug). The vibration is not really noticeable when braking lightly.

    When at speed (typically > 50mph) and braking harder than normal, I can feel the brake pedal vibrate/pulse. My passenger can also feel the vibration coming from her side of the car.

    There's some minor vibration at the steering wheel as well, but nothing major.

    I read around the web on the myths of "warped" discs and the problem of actually altering the disc material due to excess heat and overcooking the pads, is it really the problem here?

    While on track, I did not encounter any brake fade problems, brakes felt as good towards the end of the session as the beginning.

    Someone suggested sending my discs to be skimmed and to install new pads, what's ASN's verdict?
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  2. Lima
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    Lima AUSmotive.com

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    Take a look at your brake discs. If they look anything like this (below), then you probably have some pad deposits on the disc.

    [​IMG]

    That's a photo of my MINI after a track day and I must not have allowed sufficient time for cooling my brakes.

    Afterwards, the effect when braking was similar to your description. If your problem is the same then the issue should slowly disappear with general road use. It might take a week or more, but after a few days you should feel the problem lessening.

    If the problem still exists after that time then go out to a quiet road and do a few repeated stops from 60mph to 5mph in quick succession, then drive for a few minutes, or more, without using the brakes at all (if possible).

    With any luck that will fix it.
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  3. boggysv
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    boggysv Member

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    YES!!! it looks like that, but much worse, I'll grab a pic when I get home.

    edit: here they are, they seem better now after the event, but vibration is still there. Think this will go away with some more braking?

    [​IMG]

    [​IMG]
    Last edited: Aug 19, 2009
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  4. GConn
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    GConn Member

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    I have the same problem with my S3. I feel this light shaking when braking at high speeds (over 100). But there is no brake pads deposit on my discs...I hope I don't have a warped disc or a bad wheel
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  5. s3mike
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    s3mike Member

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    I did my first track day a couple of weeks back and had exactly the same issue. Slight vibration when braking at higher speeds but nothing through the steering wheel.

    I've been driving normally since the track day and the vibration is almost gone now.

    I think it's just pad deposits on the discs which eventually wear off ( as the other poster said ).

    Brakes were pretty good on the track though, no fade. I thought I had let them cool down enough but maybe a bit more would have stopped the deposits?
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  6. S3-Paul
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    S3-Paul New Member

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    I never had this problem with original set of pads, but since having them changed by local audi dealer about a year ago my S3 has suffered badly with pad deposits on discs (as previous pictures) at every track day since. Whilst the brakes don't appear to fade I'm getting vibration and deposits after the first couple of 'proper' laps which remains for the rest of the track day and a few days afterwards, until they clean up again.

    Following a track day last week where the problem was greater then ever, I think I've probably overcooked the pads, so I've just ordered some yellowstuff pads which I'll bed in properly prior to track day beginning of next month and see if that cures it.
    cheers
    Paul
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  7. phil76
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    phil76 Active Member

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    There was a post on one forum might have been here that oem brake pads have been updated or upgraded because of bad squealing on some S3's but to me this sounds like something warped or bent ie disc,wheel or even an out of shape or egged tyre
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  8. S3-Paul
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    S3-Paul New Member

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    I've ruled out wheels and tyres by using a different set at last track day. Discs could be the cause, but pads seemed more likely due to heavy pad deposits on discs (and cheaper option to try first)
    cheers
    Paul
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  9. boggysv
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    boggysv Member

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    DAmmit....do we have vibrators or cars? :mad:

    Anyways, as Lima said, the problem is slowing going away now (less severe vibration, but it's still there). No visible discoloration or whitestuff on the disc now, just minor vibrations remaining while braking hard.

    I guess there is only one answer.
    [​IMG]
    So pretty...:wub:



    (then again, I'd be embarrassed to have such a huge kit and only run a 2.50 on sepang circuit)
    Last edited: Sep 2, 2009
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  10. S3-Paul
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    S3-Paul New Member

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    phil76 appears you were right

    I’d already ordered some Yellowstuff Pads, but Car went to dealer's on Friday for routine service, and I was advised front pads 80% worn and discs warped(pads only changed 12,000 ago!) They then volunteered to change discs under warranty, with the only cost to me being a set of OEM pads. Looks like a good result to me, with 47,500 on the clock and only 3 months left of warranty.

    So car returned to dealer on Monday for discs and pads, and I then fit yellowstuff pads sometime this weekend. Leaving me a set of OEM pads to use should yellowstuff pads prove too wooden for every day use.
    #10

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