Only one piston moving

fourier transform
edited April 2017 in MTB workshop & tech
Hi all, I took my bike out the other day after about 2 years in a shed, and have been working on it to get it back to good condition. My rear brake is a Magura Louise, and on inspection only one piston moves when I squeeze the brake. I've applied pressure to the working piston to force the non-moving one out, but it still doesn't move when I don't put pressure on the working one (I.e. Use it normally) . So my question is, does the brake need bleeding/calliper need rebuilding?

Any help at all is appreciated hugely, cheers

Comments

  • cooldad
    cooldad Posts: 32,599
    Try lubing the stuck seal with some brake fluid - mineral oil not DOT. Obviously take the pads out first.
    I don't do smileys.

    There is no secret ingredient - Kung Fu Panda

    London Calling on Facebook

    Parktools
  • The Rookie
    The Rookie Posts: 27,812
    Use a wide cable tie to hold the moving one still, clean the other and then try and get it moving while the other one is held in place.

    Even an only slightly stuck piston requires a lot of force holding the moving one to get it going.
    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.