Rear brake cylinder stuck extended(closed)

[tom9286]

After 12 hours of tearing down/rebuilding my rear end I go to put my rear tire on to find my rear brake clamped shut.

Bike: 2003 yz250.

During the build i did have to smash my brake down all the way to get my rear swingarm bolt in.

All that aside now the rear brake piston seems overextended and clamped shut. I cannot seem to get it to go back in. Any suggestions, bleeding etc? I was looking for a simple solution before I drain the system to fix this.

I havn't tried more than pushing it back in and pressing the brake a few times to break it free. After working until 11pm last night on it and finnally putting the rear wheel on i was just pissed and went to bed and unfortunately im at work all day.

It appears as the cylinder is overextened. Anyone ever seen this?

 

[Papakeith]

have you cracked open the bleeder yet?

 

[tom9286]

thats my plan for tonight when I get home. Do you expect that to fix the issue? It was late last night and I didn't have time to try too much it just bugged me this mornign so much i thought id post to get a list of ideas to try when I get home!

 

[Rotorranch]

You should be able to push the piston back in. Remove the pads, and try a "C" clamp, or large adjustable pliers to squeeze the piston back in.

If that doesn't work, try loosening the bleeder screw. Use a piece of hose on the bleeder so you don't squirt yourself in the eye! Then compress the piston.

Rotor

 

[KX250Dad]

If you choose to use a channel lock, large screw driver as a pry bar, or any other simliar method to open the brake or piston faces be extremely careful.... you don't want something simple to wind up something complex and expensive. I complement you for calling it a night... generally given the same frustration I really mess things up. In so far as the brake... they should "push" back I doubt fingers can do it... I suggest getting some wood shims, the kind they use to square up door frames. There tappered and being wood you can get them started and tap with a hammer and not worry about damage from metal / metal contact. I frequently use the wood shims, one of those gotta have tools for under $3.00... great stocking stuffer.
Good Luck...

 

[tom9286]

successful.

Ended up being able to press it in with my fingers. I was just too frustrated and tired after 5 hours of straight work going as fast as I could. Since i had a deadline to be able to ride on Sat !

It went in easily. that is, pressing with my palms as hard as I could helped it enough. didn't know it was going to be so simple.

Now its on to fixing up my cracked or broken off drain plug!