Problem after bleeding Avid Juicy Sevens

Larok
Larok Posts: 577
edited July 2008 in MTB workshop & tech
Hi, I bled my brake as I could not get my rear wheel to lock.

Able to get the wheel in and spinning quietly with no rubbing on the discs by the pads.

Problem is, when I pull the brake levers once the pads are left up against the disc so it rubs and cannot be resolved by re-alligning the caliper as the pads remain pressed up against the disc.

The only thing that works is using a screw driver to seperate the pads apart by moving the pistons out a bit to get the wheel in again.

Anynow know why the pads don't return to the right position and instead stick to the discs after the first pull on the levers?

Comments

  • nicklouse
    nicklouse Posts: 50,675
    too much fluid. Or just need to re bed in. (as you seem to imply that you have moved the caliper).
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Larok
    Larok Posts: 577
    Probarbly too much fluid as I think I bled them with the pistons pushed part way in, (no spacer !).

    How do I let fluid out without introducing air? and should I?
  • nicklouse
    nicklouse Posts: 50,675
    syringe into lever end with some fluid in and suck this will remove excess fluid and air.

    But from what you are saying i feel you did not use the avid bleed kit? which means that you can not bleed the system as avid say? so you may have got a lock somewhere.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Larok
    Larok Posts: 577
    I used the Aviid bleed kit. Followed the instructions from the manual and you tube. Didn't have any pad spacers though, so dont know if that caused the problem?
  • nicklouse
    nicklouse Posts: 50,675
    not really just attach syringe to lever (with fluid in) push pistons home and suck till no bubbles. Now before disconnecting try the brakes are the pistons retracting? if not then something is wrong with them. i would pop them out and lube the seals (well, possible to do with out removing if careful) push the pistons out a bit and clean sides with dot4 or... on a cotton bud. push home and check for ease of movement.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Larok
    Larok Posts: 577
    tried with the lever synringe. Pads still dont retract. Thanks for the advice, will take a look at the pistons next.
  • Larok
    Larok Posts: 577
    having had a look at the pistons the small round column in the middle is no longer square faced, looks as though I may have damaged them opening out the pistons. The pad no longer sits square on them and is more closed at the top than the bottom. Have a killed them?

    what's the replacement?
  • mr mangos
    mr mangos Posts: 174
    edited July 2008
    ...
  • Larok
    Larok Posts: 577
    Here is a pic of the piston.

    http://www.pinkbike.com/photo/2205873

    I'm assuming I'll have to replace them. is their anywhere I can get instructions to do this?
  • stumpyjon
    stumpyjon Posts: 4,069
    Not a lot of help this time I know, but keep a set of old pads for the future, slip these in if you need to reposition the pistons in future.
    It's easier to ask for forgiveness than for permission.

    I've bought a new bike....ouch - result
    Can I buy a new bike?...No - no result
  • Larok
    Larok Posts: 577
    I will, lesson learnt!

    I'v ordered this kit, is it the right one?

    http://www.chainreactioncycles.com/Mode ... elID=26186