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  1. #1
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    Why are my XT brakes (785's) not stellar?

    I upgraded from the stock Shimano M4-somethings to a set of 2011 Xt brakes a few months ago based on the stellar reviews. Admittedly, my local mechanic gave me a screaming deal, and I thought I was getting the newest version when he said "this year's model" but I ended up with the previous version (not the 2012's).

    When I first got them, they were incredible! They were silent, had great power and considerable modulation. Over the past 8 months of use, however, they have gotten "mushier" with less power and less modulation. I can essentially pull the level almost all the way to the bar and still don't get that "stop on a dime" feeling.

    I have had the mechanic that mounted them, and another, check the mineral oil levels and both felt they did not need to be bled. I got a new set of pads thinking that was the problem, but didn't install them because when I took the old ones out and checked them, they have PLENTY of life left.

    Any thoughts as to why they may not be performing up to expectations? Are my expectations too high for these? Are the 2012's really that much better? I've got a set of Elixer R's on my 2009 Stumpy and for all the issues I've read about them, they outperform the XT's in every way!

    Thoughts?

  2. #2
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    XT's are good brakes, however it sounds like they do have air in the system. Have your mechanic check them again. I trust the proper fluid is in the system!!! The Avids ar also good brakes, but try to get the XT's bled and set up properly. Good luck

  3. #3
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    Fluid level is not necessarily a good measure of air in the lines. It sounds like a bleed is in order.

  4. #4
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    Best thing you can do is hit up YouTube and learn how to bleed the brakes yourself.

  5. #5
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    Quote Originally Posted by skoda View Post
    The Avids ar also good brakes
    Not in my experince! My XT 785's are though!

  6. #6
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    Thanks,

    I trust both techs, but I agree - it seems as though it's at least worthwhile. Bleeding brakes is definitely a skill on my "need to learn" list. Looks like its time to cross it off the list!

    Thanks,
    Brian

  7. #7
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    The process for Shimano brakes is very easy. It's a good place to start that leaves little chance of error. When I first learned to bleed brakes it was a scary line to cross. It was, at the time, a very unknown area to me. I still have much to learn but practice makes perfect.

  8. #8
    Just a flesh wound
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    Quote Originally Posted by trumpus View Post
    Thanks,

    I trust both techs, but I agree - it seems as though it's at least worthwhile. Bleeding brakes is definitely a skill on my "need to learn" list. Looks like its time to cross it off the list!
    Mushy feeling with too much throw has bleed written all over it. The XT's are great brakes (at least really, really good) and they should perform like new every day. Take the pads out and remove the caliper from the frame before you even think about cracking the bleed port. Watch the videos on Youtube. Read the Shimano instructions and just go slow. If you have someone to help you, that makes life a lot easier. The helper can squeeze the lever and hold it while you open and then close the bleed port screw. If you don't have a helper, use a couple of thick rubber bands to squeeze and hold the lever for you. When you add fluid to the reservoir, push the lever forward to allow any air in the line to bubble up into the reservoir. Tap the caliper and lines and you should be good. Make sure you have a good spacer to keep the pistons fully retracted during the bleed.
    My name is Chris and I ride a Prophet 650b with a Lefty.

  9. #9
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    sounds like it needs a full bleed

  10. #10
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    Quote Originally Posted by R+P+K View Post
    Best thing you can do is hit up YouTube and learn how to bleed the brakes yourself.
    +One

  11. #11
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    Quote Originally Posted by patineto View Post
    +One
    It's what I did when my brakes needed a bleed. The only costs were some oil and time.

  12. #12
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    Also check the brakes for small leaks, XT brakes shouldn't go mushy within 8 months. The most likely place for a small leak is the banjo bolt area where the hose attaches to the caliper. Squeeze the lever as hard as you can and see if there's any fluid seeping out from this area.

  13. #13
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    Thanks. No leaks that I can see. Planning to bleed today or tomorrow, depending on whether I can track down supplies today.

    Does anyone recommend removing the caliper (as shown in this video, which I realize is a demo, but it seems like a pretty clean process: http://www.youtube.com/watch?v=dFuwoEYvt_w)?

    I was going to pick some syringes, tubing (4mm?), a few bottles to catch overflow and fill reservoir and some Shimano oil - anything else I need?

  14. #14
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    Quote Originally Posted by trumpus View Post
    Does anyone recommend removing the caliper (as shown in this video, which I realize is a demo, but it seems like a pretty clean process
    Removing the caliper takes 30 seconds. No reason not to do it if it makes any other part of the process easier for you.
    Voodoo Canzo 29er (sporting a Lefty) + Raleigh XXIX SS + Traitor Crusade SSCX + Lapierre Xelius XDJ

  15. #15
    fliernh
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    A stuck piston also gives that same feeling. Ive never had one on XTs but have on Magura and that is the way it presented. Even had a mechanic bleed them once and didn't still didn't fix the mushy feel but then unstuck the piston and all was good.

    Just a thought.
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