why wont the pistons go back in

Hepi1986
Hepi1986 Posts: 8
edited July 2011 in MTB workshop & tech
Hi, guys, I have a problem and would like some help.
I have Avid Elixir 5 brakes in my Remedy, they were bled by myself yesterday, now the pistons on both brakes wont go in to the calliper enough to fit new pads, on the rear it is more pronounced, where 1 piston moves and the other doesn't.
it's fair to say that it is driving me round the bend. Any help or advice would be appreciated.

Comments

  • nicklouse
    nicklouse Posts: 50,675
    too much fluid in the system.

    I guess you did not use the spacer blocks that come with the Sram bleed kit.

    release the bleed port on the lever and then push the pistons back.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Hepi1986
    Hepi1986 Posts: 8
    Ok, the outside piston has gone back in but the other appears to be stuck, is this normal? Also the lever does not make the pistons move now does this mean I need to bleed the rear again?
  • nicklouse
    nicklouse Posts: 50,675
    Ok it sounds like you have jammed the piston and have not bleed the brakes correctly.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Hepi1986
    Hepi1986 Posts: 8
    how do I un-jam the piston?
  • nicklouse
    nicklouse Posts: 50,675
    push it out.

    and this is where the fun starts. as it is the other piston that moves.

    try putting the bleed block in (or something else) and pull the lever hard, that may straighten the piston.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • apreading
    apreading Posts: 4,535
    With the stuck piston on my Juicy 3's had to take the calipers apart, place a wooden block against the piston and bang it with a hammer to get it back in. Fortunately someone did it for me and showed how!

    I am hoping that this will have freed it and it wont jam again...
  • Matt 24k
    Matt 24k Posts: 186
    You should be able to use the pressure in the system to push out the stuck piston. You need to clamp the free piston as far in the caliper as you can. A couple of thin pieces of steel and 2 clamps or mole grips is what you need or some G clamps. Make a sandwich around the free piston and outer part of the caliper with the steel strips and clamp together. You should then be able to pump the stuck piston out. Do this very slowly unless you want the piston and fluid all over the floor. What you are trying to do is get the piston square again in the bore as it is probably off centre.
    If you are stuck for steel strips and are a brave or single man then try the cutlery drawer ;-)
  • nicklouse
    nicklouse Posts: 50,675
    apreading wrote:
    With the stuck piston on my Juicy 3's had to take the calipers apart, place a wooden block against the piston and bang it with a hammer to get it back in. Fortunately someone did it for me and showed how!

    I am hoping that this will have freed it and it wont jam again...

    best way to fuck things up that i know.
    "Do not follow where the path may lead, Go instead where there is no path, and Leave a Trail."
    Parktools :?:SheldonBrown
  • Hepi1986
    Hepi1986 Posts: 8
    thank you everyone for your help and advice. Got everything working again and it's pretty much perfect.
    thank you all

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