pulsation while braking | FerrariChat

pulsation while braking

Discussion in '308/328' started by 11506apollo, Oct 13, 2015.

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  1. 11506apollo

    11506apollo F1 Rookie Silver Subscribed

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    Hi. I am getting a pulsation on the brake pedal when applying the brakes. The higher the speed, the higher the pulsation frequency, therefore I suspect a warped rotor.(s). they are both original with approx. 18,5 k miles on a 82 GTSi. It is mostly on the pedal, with little to none at the steering wheel. Should I get the car to a local break shop to have them measure the thickness and warp of the front rotors? or, should I assume they are warped and no sense in "turning" the rotors, so go straight to purchasing replacement rotors and pads? Lots of threads on here about replacement rotors and pads, so I will wait for comments before taking any further steps. Thanks!!
     
    11506apollo, Oct 13, 2015
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  2. Meister

    Meister F1 Veteran Silver Subscribed

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    yes most likely just replace rotors and pads.
     
    Meister, Oct 13, 2015
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  3. 2NA

    2NA F1 World Champ Consultant Owner Professional Ferrari Technician

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    "Warped" rotors usually aren't really warped. It is often just an uneven micro-layer of brake pad material on the rotor surface that results in the jerky pedal. If the rotors are still within thickness limits, a very light cut on a brake lathe and a new set of pads followed by proper bedding should do it.
     
    2NA, Oct 13, 2015
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  4. 11506apollo

    11506apollo F1 Rookie Silver Subscribed

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    I can measure the thickness of the rotors using a caliper. What is the min. thickness for these rotors? thanks.
     
    11506apollo, Oct 13, 2015
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  5. stradman

    stradman Formula 3

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    Either the rotors as mentioned above or you have a very early prototype ABS system on your car! : )
     
    stradman, Oct 13, 2015
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  6. 2NA

    2NA F1 World Champ Consultant Owner Professional Ferrari Technician

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    20mm, I believe.
     
    2NA, Oct 13, 2015
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  7. 11506apollo

    11506apollo F1 Rookie Silver Subscribed

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    Last edited by a moderator: Sep 7, 2017
    11506apollo, Oct 13, 2015
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  8. mike996

    mike996 F1 Veteran

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    Did this just start happening "on its own" or were any wheels recently removed/reinstalled?

    If wheels were removed...

    My Porsche 911 did that any time the wheels removed/reinstalled if the lug nuts were not tightened in the proper pattern and to equal torque. Loosening the wheel/retightning in a "cross pattern" and to the same torque corrected it.

    I don't know if 3x8s exhibit the same issue re lug nut tightness but it's worth checking in any case - takes two minutes and there is no need to raise the car, just break the bolts loose and retighten in a cross pattern with a torque wrench.

    Otherwise, I concur with the suggestions re the rotors.
     
    mike996, Oct 14, 2015
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