XT Brake Issue

Discussion in 'The Workshop' started by policedutchdog, Jun 1, 2009.

  1. policedutchdog

    policedutchdog New Member

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    I'm having a problem with my XT brake caliper. When the brakes are applied only one of the pistons are engaging. The other piston seems stuck and have had little success getting the piston to work. Are the calipers repairable or is the problem in the brake lever itself.

    Scott
     
    policedutchdog, Jun 1, 2009
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  2. 07coiler

    07coiler Banned

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    The Calipers are repairable. I had same problem with my 9's. Not to familure with xt though. I just to the hayes webiste and downloaded the manuel and it showed me how to take the caliper apart. Took me about 45 mins to figure it out. Shouldnt be to hard. How old are the breaks? Pistons tend tend to do that if they sit for a while or if there just an older break.
     
    07coiler, Jun 1, 2009
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  3. Rob

    Rob Active Member

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    Rob, Jun 1, 2009
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  4. Terry

    Terry New Member

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    I have found this to be a very common symptom with the latest generations of Shimano Disc Brake systems as the brake pads (and subsequently the pistons) tend to be exposed more. Therefore dirt, dust what have you will cause the pistons to get sticky.

    Quick fix: Remove pads, clean the inside of the caliper with clean streak or rubbing alcohol and a rag. Then drop a drop of lube (Triflow black label works great) on the exposed piston. Clean off excess lube and then push that piston back into the caliper body. Now, hold that one down in place with a box wrench while squeezing the brake lever to dislodge the stuck piston. Once she comes out you'll want to clean her up as well and then drop a drop of lube as you had done with the other piston. Wipe off excess and press back into caliper body with box wrench. At this point I will squeeze the brake and see if the pistons will extend equally. If I find one is favoring to one side I will expose that stubborn piston a more so then before and lube again. Eventually you'll get equal movement. What I then do after reinstalling pads and inserting disc/wheel is loosen caliper bolts, spin wheel/disc and then squeeze the brake (this will re-center the caliper). Tighten bolts from there.

    I only do this when I encounter sticky pistons with Shimano setups.

    -Terry
     
    Terry, Jun 2, 2009
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