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  1. #1
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    How Do I Fix a Sticky Piston

    SRAM just replaced my brand new 2012 XX brakes for their 2013 XX brakes and I am still getting some noise. I have seated them with a few brake slowdowns, but only ridden off road once. My first question is does it take more than one ride to get them broken in and reduce any noise.

    2nd, the 2012s were making noise because one of the pistons was sticking. This could be the same problem with the new ones, so what is the best way to get a piston un-stuck and moving correctly?

  2. #2
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    Noise as in noise all the time? Or just when braking? Squealing or dragging noise?

    If noise all the time (meaning you probably have drag too):
    1) I find centering the normal way (loosen bolts, grip handle, tighten bolts) doesn't always do the trick because one piston or the other always seems travel further. So, you can micro-adjust the center by putting a piece paper, or a business card, on one side during centering, to nudge it one way or the other while tightening down the bolts. This is more a soln for drag however, and won't necessarily fix squealing under braking. If its dragging in one spot only (slightly bent rotor) do all the above with rotor rotated so that the dragging part is in the piston.

    2) To actually fix a slow or stuck piston: remove wheel, remove pads, and very, very carefully grip the brake lever to move the pistons out a little. You can also use the plastic spacers that come with the new brake here too, to make sure you don't extend the pistons too far (EDIT: on some brakes, with pads removed, included plastic shipping spacer is not enough. So be VERY careful here). With the pistons fully extended, using a GUM tuft brush like this one brush all around the base of each piston with alcohol. Use a plastic tire level to push the pistons back into the caliper. You may need to repeat several times.

    Hope that helps.

  3. #3
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    Great, thanks.

  4. #4
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    I dunno on the Avids, but I know the Shimano guys say to "lube" the piston with a few drops of their mineral oil. You might need to do that to the Avids too after you get them clean.

  5. #5
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    Mineral oil is for mineral oil based systems. The o rings on Avids can be damaged by doing this I believe. A drop of DOT applied to the pushed out piston with a toothpick is what I do. Work piston in and out, and spray down with alcohol.
    Quote Originally Posted by scottap2003 View Post
    I dunno on the Avids, but I know the Shimano guys say to "lube" the piston with a few drops of their mineral oil. You might need to do that to the Avids too after you get them clean.
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  6. #6
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    Noise on Avid brakes, something people have been writing about for a very long time. You'll read thread after thread after thread. My only answer to that one was to swap the rotors. Seemed no matter what I did with the Avid rotors, they'd find ways to get growly and squeaky. I've put Ashima rotors on and they've been great ever since.

    Good luck with that.

  7. #7
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    This is more a soln for drag however, and won't necessarily fix squealing under braking. If its dragging in one spot only

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