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  1. #1
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    Too much lever travel on new XTs

    I just bought a pair of XT disc brakes and noticed that there is way too much lever travel before there is any meaningful engagement (the free stroke screw is turned in all the way). A friend of mine who has the same brakes has much less travel before the pads engage the rotor. Also, the brakes feel pretty solid when they engage, so I don't think it's a bleeding issue, and I've done the "gravity bleed" thing a few times.

    A guy at a bike shop said I could resolve this dead travel issue by pumping the pistons out and pushing them back in a few times (with the pads removed). He said it would do something to the seals, but I haven't had any luck with this.

    What I've done to resolve the issue is to pump out the pistons a bit, so that the pads engage quicker, and filled the reservoir to make up for the extra room. This seems to work, but now the rotors rub against the pad. Plus, this doesn't seem like the right way to resolve this issue.

    Is there a better way to fix this problem?

    Thanks!

  2. #2
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    Reputation: XSL_WiLL's Avatar
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    I don't like doing the gravity bleed. It's quicker and more thorough to use a syringe and push fluid from the bottom to the top.

    You can just pump out the pistons a little bit less. And there's no need to overfill the reservoir.

  3. #3
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    Quote Originally Posted by XSL_WiLL
    I don't like doing the gravity bleed. It's quicker and more thorough to use a syringe and push fluid from the bottom to the top.

    You can just pump out the pistons a little bit less. And there's no need to overfill the reservoir.

    Thanks. So you think it's a bleeding issue even though the brake feels pretty solid once it engages? Also, I don't have the "professional" bleed kit, which includes the syringe and the clamp/bottle thing that goes on the reservoir, and I haven't been able to find the clamp thing any where, so I'm not sure how to bleed from the bottom like you're suggesting. Any suggestion on a DIY way? I'm pretty sure I can find a syringe any where but don't know about the clamp thing.

  4. #4
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    Quote Originally Posted by LowLow
    Thanks. So you think it's a bleeding issue even though the brake feels pretty solid once it engages? Also, I don't have the "professional" bleed kit, which includes the syringe and the clamp/bottle thing that goes on the reservoir, and I haven't been able to find the clamp thing any where, so I'm not sure how to bleed from the bottom like you're suggesting. Any suggestion on a DIY way? I'm pretty sure I can find a syringe any where but don't know about the clamp thing.
    You don't really need the clamp. You can just let it overflow and clean up later, or you can have a helper suction up excess at the resi.

    It may not be a bleed issue, but it probably isn't if the lever feels solid.

    Level the lever and take off the resi cap so that excess fluid can flow out. Reset the pistons completely. Replace resi cap. Pump out the pistons a bit.

    You can also play with the reach. Sometimes if you dial in the reach real far, the lever pulls very close to the bar.

  5. #5
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    I read here in MTBR that someone has luck using rubberband to engage the brakes overnight. It did shorten the travel. Maybe you could give it a try?

  6. #6
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    Quote Originally Posted by Kaizer
    I read here in MTBR that someone has luck using rubberband to engage the brakes overnight. It did shorten the travel. Maybe you could give it a try?
    It's a temporary fix at best, not a permanent solution.
    Axle Standards Explained

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  7. #7
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    Quote Originally Posted by Kaizer
    I read here in MTBR that someone has luck using rubberband to engage the brakes overnight. It did shorten the travel. Maybe you could give it a try?
    It usually firms up the brake lever. It helps if there's air in the system.

  8. #8
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    Quote Originally Posted by LowLow
    What I've done to resolve the issue is to pump out the pistons a bit, so that the pads engage quicker, and filled the reservoir to make up for the extra room. This seems to work, but now the rotors rub against the pad. Plus, this doesn't seem like the right way to resolve this issue.

    Is there a better way to fix this problem?
    I only have experience with Avid, not Shimano brakes, but it sounds to me as though your bleed procedure is successfully getting all of the air out of the system, although perhaps not leaving the right volume of fluid in the system. Too little fluid should give you a lever with too much travel before the pads engage the rotor, and too much should prevent the pistons from retreating enough to eliminate rub.

    Given this, I believe XSL_WiLL's suggestion to remove a small amount of fluid from the system will work for you.

    If you find this puts you back to the original situation where the lever travel is excessive but firm once engaging, you can try removing the caliper and putting a flat piece of metal that is slightly narrower than the rotor between the pads, then giving the lever a few good squeezes. This may allow the pistons to adjust outward enough to give the proper lever feel (although it sounds like you may have essentially tried this already with some of the things you've been doing).

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  9. #9
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    Is this a new pair of new XT brakes or a used pair of new XT brakes? That sounds like what you get with well worn pads, or rotors that are too thin. They might also be underfilled. Are you pushing the pistons all the way in and using the spacer to do the bleed?
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