Aid Juicy 5 pad binding on disk

rain-chaser
rain-chaser Posts: 27
edited March 2009 in MTB workshop & tech
Hi there,

The pad on the caliper side of the brake unit permanently rubs against the disk of my Trek 6700. When I push the pad and piston back using a scredriver it's fine, but when I apply the brake for the first time the pad doesn't seem to retract fully. This problem is occuring on both front and rear brake sets...

Bike is only 8 months old and pads and disks still in good condition...

Any thoughts?

Thanks

Paul

Comments

  • ratty2k
    ratty2k Posts: 3,872
    Wheel still spin freely? Or is it binding up?
    My Pics !


    Whadda ya mean I dont believe in god?
    I talk to him everyday....
  • hiya and thanks for your reply... compared with the piston retacted with a screwdriver versus after the brakes have been applied - the wheels definately spin less freely afterwards if that makes sense?!

    Cheers

    Paul
  • ratty2k
    ratty2k Posts: 3,872
    I'd remove the wheel, remove the pads and put a drop of brake fluid on the offending piston. But, provided its just rubbing gently I wouldn't get too worried. You could also try re- centring the caliper as well....
    My Pics !


    Whadda ya mean I dont believe in god?
    I talk to him everyday....
  • Thanks Ratty I'll give that a go. How do you re-centre the caliper I'm new to disk brakes!

    Thanks again

    Paul
  • ratty2k
    ratty2k Posts: 3,872
    You should see 4 bolts on the brake. 2 will fasten a braket onto the fork. the other 2 are the ones to slacken a bit. Slacken the 2 bolts off. Pull the brake lever and re-tighten the 2 bolts. Should be ok then. But like I say a little rubbing is fine...
    My Pics !


    Whadda ya mean I dont believe in god?
    I talk to him everyday....
  • dav1
    dav1 Posts: 1,298
    I had this problem for months. In the end i tried the following:

    1. remove wheel and pads, use an 8 mm spanner to hold the good piston and squeeze the leaver to move the stuck piston out a bit (be very careful not to go too far otherwise you will eject it from the calliper!). Clean with meths and apply dot fluid, push it back and wipe away the excess.

    2. Recentering the calliper (weekly) - this got very very annoying after a while

    3. Bleeding it

    None of these really worked, though depending on why your piston is stuck one may be the solution.

    For me the answer was:

    4. Too much fluid in the system. adjust the leaver so the bleed pot faces stright up. Reset the pads in the calliper and open the bleed port slightly. If fluid comes out wipe away the excess and close the port.

    hope these suggestions help
    Giant TCR advanced 2 (Summer/race)
    Merlin single malt fixie (Commuter/winter/training)
    Trek superfly 7 (Summer XC)
    Giant Yukon singlespeed conversion (winter MTB/Ice/snow)

    Carrera virtuoso - RIP
  • HI there,

    Yeah I think number 4 may well be the answer but I'll need to get myself a set of star sockets to undo the bleed valve first...will try to get that done at the weekend and will let you know what happens!

    Cheers

    Paul