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  1. #1
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    Brake lockup with heat?

    A puzzling thing is happening to a friends bike and wanted to toss it out here for opinions.
    He has juicy 7's which he put on last year(new) and has several rides on (Bike is a Blur XC).
    He rode once this year when the outside temp was about 50.
    This weekend it got around 70 and his brakes (both front and rear) locked up. Brings the bike to the basement where it is cooler and it is back to fine.
    I only half believed him but we just had the bike here in work and it was fine, he rode it outside and in about 2 minutes both wheels were locked!!

    My first thought was air in the lines expanding in the heat, but even air wouldn't heat up that quickly I wouldn't think. We are going to bleed the lines and then do a full flush if that doesn't help. But I have never heard of this, and couldn't find much with a search.

    His bike travels in the back of his pickup so it wasn't even inside a closed up car to get that extreme heat...

    Any ideas let me know.
    Mike
    - mike -

  2. #2
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    Reputation: vk45de's Avatar
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    I would venture to guess fluid expansion in a closed system. If that's the case, just removing a little fluid from the reservoir should solve the problem. Hold the breed and full flush for now.

  3. #3
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    It's possible the pistons were not all the way back when the system was bled last.
    Lead by my Lefty............... right down the trail, no brakes.

  4. #4
    Meh.
    Reputation: XSL_WiLL's Avatar
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    It's not a closed system.

    But... it sounds like the system does not have enough volume to compensate for the heating fluid. The system sounds overfilled.

  5. #5
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    Only a guess...
    May be they are overfilled and the bladder is already expanded, so it cannot expand further to compensate for the heat.
    Bleed them and see what happens.

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