XT Brakes Don't Work

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    • #240675

      I made a bad decision by buying a used hydraulic XT brakeset. I used the current rotors that were on my bike and the back has the problem of extreme squealing and no power. The front doesn’t have enough power to stand on the front wheel. I have tried sanding, cleaning with alcohol, disk break cleaning- everything I could find. Is it possible or common for these brakes to leak- causing continuous deterioration? Should I get new rotors or pads first? Metallic pads? Or should I just go back to the BB5s I had on before?

    • #240689

      I run XT (8000’s) brakes (calipers and triggers) with Ice-Tech disks and metallic pads (J04C).  I’ve never experienced the issues you’ve run into, and haven’t heard of anyone I ride with indicate that either.  Never have any noise, binding, etc.  For me, they’ve been rock solid.  Some riders aren’t a fan of their tight modulation, but I prefer that personally.  I don’t know what your experience with working on bikes is, so sorry if I state the obvious.  If I were to by a used set, I would replace pads and disks regardless of what condition they’re in using Shimano Ice-Tech disks and Shimano metallic pads.  I’d also flush (completely replace) and bleed the fluid using Shimano’s mineral oil.  If you can’t do this yourself, it’s worth the $20 or so to have it done.  This effort will give you a good baseline of the system.  Beyond all of this, there’s always a possibility the calipers are damaged.  Your LBS can check them out of you have them do the fluid flush work.  If there’s leaking (I assume at the hose ends), it’s possible the olive’s are compromised.  If so, they should be replaced during flushing/bleeding.  One note about squealing… if disks aren’t centered, they may ever so slightly rub and start to generate a squeal.  When mounting a wheel, after securing the axle, I’ve always been on the habit of slightly loosening the caliper mount bolts, pulling the brake lever, and re-tightening the bolts (while still holding the lever down).  Yeah, not really needed, but it ensures alignment in case I didn’t squarely mount the wheel. Again, if you’re bike mechanically inclined, sorry for stating the obvious.

    • #240691

      I have had this happen with several brakes not just xt. The cause for me was being dumb when i bleed them and got a bit of oil on the pads. It doeant take much to oil to contaminate the pads and once this is done they will squeal like crazy and have no power. Depending on how bad they are contaminated sometimes they will get cooked clean over time but in other cases they dont. I suspect a similar thing happened with the previous owner of thise brakes.

    • #240695

      I would say first replace the pads as that is a much cheaper replacement. You may want to have them bled at the LBS if your not 100% confident on doing it yourself.   If that does not fix the issues you should pull the wheel and pads and wrap a thin rag around a bleed block and pull the lever a bunch to see if there is leaking at the caliper. If there is then you have bad seals at the caliper and probably need to replace (or return).

    • #240858

      My old bike which I just replaced and use as a road bike now has XT brakes from 2005 and they have performed flawlessly for 13 years. Try the new pads and next a larger front rotor. Bigger guys need bigger parts, I’m light.

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