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  1. #1
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    Power loss from cold to hot temp.

    I bled my new XT brakes with great success. Brakes were working fine.
    I'm in central Ontario and I took my bike from the garage (-3 c) to inside the house overnight. Next morning, a couple drips of oil on the floor and no braking power whatsoever.

    Any thoughts?

  2. #2
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    Sure sounds like a leak. Were you able to determine where the oil leaked out?

    Short of anything else, I would try bleeding again in the warm environment. Although the brake system should be able to handle the temperature change with ease, there may have been some air trapped in the cold environment that expanded with the temp increase (the system should easily handle this relatively minor pressure change, though, and certainly not cause it to leak).

    Good luck,
    Pete
    I can barely get my mouth around it.

  3. #3
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    Mineral oil doesn't like cold temperatures
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  4. #4
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    I'll make sure everything's tightened and I re-bleed.

  5. #5
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    Quote Originally Posted by Thatshowiroll View Post
    I bled my new XT brakes with great success. Brakes were working fine.
    I'm in central Ontario and I took my bike from the garage (-3 c) to inside the house overnight. Next morning, a couple drips of oil on the floor and no braking power whatsoever.

    Any thoughts?
    The temp change is not an issue nor is the cool temp....

    I ride my bike all winter long it goes from -10C to +20C every work day over the winter.

    Nope you have a fluid leak....

    find it and fix it...looks like the bleed didn't work quite as well as you first thought.

    You may also have overfilled the reservior.

  6. #6
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    Quote Originally Posted by jeffscott View Post
    The temp change is not an issue nor is the cool temp....

    I ride my bike all winter long it goes from -10C to +20C every work day over the winter.

    Nope you have a fluid leak....

    find it and fix it...looks like the bleed didn't work quite as well as you first thought.

    You may also have overfilled the reservior.
    From what I've read, you're supposed to fill the reservoir so that it spills out when you put the top back on.

  7. #7
    CSC
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    Quote Originally Posted by Thatshowiroll View Post
    From what I've read, you're supposed to fill the reservoir so that it spills out when you put the top back on.
    This makes sense, as you don't want air in the system (hence the bleeding process).

    This smells like a faulty caliper (I assume the oil on the floor was located below a caliper). It happens, and Shimano should be more than happy to send you a new one.

    Though I'd look at the lines and make sure they are not cracked. Should be just fine with temperature swings...-3C is not that cold, all things considered.

  8. #8
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    had to do the conversion, 26 isn't that bad. i was racking my brain and i agree with the above. make sure you re- bleed the system at room temperature, get allllllll/as much air out as you can and the slight over fill.
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  9. #9
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    Quote Originally Posted by shwinn8 View Post
    Mineral oil doesn't like cold temperatures
    -3 C isn't that cold...
    Banjo bolt problem, as discribed elsewhere ?
    Belgian beer and Scotch whisky.

  10. #10
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    Quote Originally Posted by thasingletrackmastah View Post
    -3 C isn't that cold...
    Banjo bolt problem, as discribed elsewhere ?
    Quote Originally Posted by shwinn8 View Post
    had to do the conversion, 26 isn't that bad.
    I know, I typed it myself. [enter sarcastic remark here about not reading the entire thread prior to making an empty comment] .
    Last edited by shwinn8; 01-09-2013 at 06:09 AM.
    '11 Jedi
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  11. #11
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    Quote Originally Posted by Thatshowiroll View Post
    From what I've read, you're supposed to fill the reservoir so that it spills out when you put the top back on.
    Well the fix is simply re bleed the brakes at room temp and fill fully or re bleed the brakes and -3C and leave a bit of space.

  12. #12
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    Quote Originally Posted by shwinn8 View Post
    Mineral oil doesn't like cold temperatures
    Why? Had been driving this winter in -22c with no problem. Of course the colder it is, the thicker the oil gets. That causes the brake to feel different, but performance-wise it works as well as in +30c.

  13. #13
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    The hoses and banjos are all brand new from Jagwire.
    I re-bled and that seems to have worked. I tightened all the fittings and so far no sign of an oil leak

  14. #14
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    Looks like the leak is coming from the reservoir at the lever. The rubber gasket is in properly and the screws can't get any tighter. ???

  15. #15
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    Quote Originally Posted by Thatshowiroll View Post
    Looks like the leak is coming from the reservoir at the lever. The rubber gasket is in properly and the screws can't get any tighter. ???
    You need to loosen the screws...they should be snug, but not cranked down. Just like the gaskets in your house plumbing (toilet, sink, etc...), if you crank down the fittings on the gaskets, you can force them out from under the fitting interface, and even damage them.

    I'd say you probably need a new gasket, as the current one has been squished, and maybe torn at a level that you can't see, but allows fluid to escape.

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