Brake troubles

MC1
MC1 Posts: 9
edited December 2012 in MTB workshop & tech
Have been trying to give my brakes a service and got stuck :(

Front whent ok and i have good presure. With the rears however theres a problem with the bolt that tightens the line to the caliper. The front brake has plastic line and is secured with an allen key type bolt.
The rear is metal braded line and is secured with a hex spanner type bolt probably 9 or 10mm) and it just wont tighten. it starts to get tight but then slips to loose then gets tight again etc. (never tightens propperly)
If i bleed the system with the bolt as tight as it will go it will work for a few pulls but then pop fluid comes out.

Is this a problem with the bolt or the thred in the caliper? the back caliper has never had good presure (realy hard to skid) and it has leaked from there before.

Comments

  • dusk
    dusk Posts: 583
    Sounds like you've stripped the thread
    YT Wicked 160 ltd
    Cotic BFe
    DMR Trailstar
    Canyon Roadlite
  • MC1
    MC1 Posts: 9
    I thought that but if i remove the hose completly and screw the bolt directly into the caliper it tightens all the way down :? im thinking maby its the wrong type of bolt for the braded lines, or i need new/larger O rings. or both
  • The Rookie
    The Rookie Posts: 27,812
    The bolt screws into the caliper, the O on the banjo fitting is irrelevant.

    Mayve you can find a thinner banjo so the bolt screws in further but it sounds like new caliper time.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • MC1
    MC1 Posts: 9
    but why would the bolt screw all the way tightly into the caliper but with the brake hose inbetween start slipping? the banjo is too thick like you sugested. or maby the bolt is too short.
  • nicklouse
    nicklouse Posts: 50,675
    Sounds like stripped threads.

    Why. You are not tightening on the striped bits when the hose is not there.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • The Rookie
    The Rookie Posts: 27,812
    Agreed, you don't put any load on the threads when not clamping anything up and then you screw in further to undamaged thread...
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • MC1
    MC1 Posts: 9
    ok cheers i can see where your coming from now.

    looks like ill have to try and find a cheap 2nd hand brake and lever off ebay :(
  • nicklouse
    nicklouse Posts: 50,675
    what are the brakes?
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • MC1
    MC1 Posts: 9
    http://www.bikeradar.com/forums/viewtopic.php?t=12890220&p=17989539

    see my pictures on this thred. i believe them to be shimano br-m755 deore xt brakes

    there very old 10 years at least
  • The Rookie
    The Rookie Posts: 27,812
    Quite old, plenty still pop up on fleabay quite often though and like all things Shimano they are pretty reliable.
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.
  • MC1
    MC1 Posts: 9
    The Beginner wrote:
    Quite old, plenty still pop up on fleabay quite often though and like all things Shimano they are pretty reliable.

    TBH doesn't have to be a matching pair, any rear brake will do. Watching a few on ebay. Hope, avid and shimano.

    I actuly wanted to go from my trails bike to a decent mountain bike at. Some point for the extra gears, higher riding position etc..
  • The Rookie
    The Rookie Posts: 27,812
    If you can find just a caliper you'll save a wedge....

    there is a 755 rear caliper on ebay right now although it sounds like the banjo bolt thread is stripped though......... coincidence?
    Currently riding a Whyte T130C, X0 drivetrain, Magura Trail brakes converted to mixed wheel size (homebuilt wheels) with 140mm Fox 34 Rhythm and RP23 suspension. 12.2Kg.

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