Hi everyone after a bit of help I have recently changed the front pads on my 2005 rev 3 I had to push the pistons back to get new pads in this was easy no corrosion and pushed back with my thumbs however I did split the caliper to make this easier.I have back bled the brake and don't think any air is still in there now my problem when I push the pistons back I have no pressure at the lever if I pump a few times I get pressure but after a bit of use the pistons stay out about 2-3mm and brake gets very hard not much movement in lever if I push pistons back some thing happens over again

Any ideas what would solve this or advice would be great as I am confused over this at the moment thanks

http://www.trialscentral.com/forums/topic/60500-rev-3-front-brake/#entry427986

I have tried all the things suggested in the post but still get this very hard lever after a couple minutes of riding and pistons out a few mm not sure if it's still air in system somewhere or something else

Do you all think this could be caused by air still being in the caliper as I xan easily push pistons back with screwdriver or by hand if caliper is split after this brake is soft pulls back to bars and after a few mins riding gets hard and outside pistons have stuck out really annoying Me now just want to get out and practice lol

Does the brake work? Have you tried it on the bike?

 If you tighten the adjuster TOO much the fluid CANNOT return to the master cylinder.

I have tried the brake on the bike it works but just gets more and more pressure at the lever and pistons stick making brake bind I have adjusted lever all the way out still same thing happens

Had this with my rear brake after changing pads and having a nightmare bleeding it, took it for a ride and the brake was sticking like crazy - the heat causes the disc to expand and it will lock on until it cools down.
I knocked down the adjuster on the pedal which totally resolved the issue.

The movement when you activate the brake is very very small, millimeters.

If the pistons in the caliper are fine and moving freely & it's bled properly with no air, only thing I can suggest is your adjuster on the lever.

Make sure you're getting a full return on the master cylinder when bleeding otherwise it wont bleed properly.. I took the lever off and used an allen key and a rag to activate the cylinder to make sure I was properly pushing the cylinder to it's limit then disengaging completely.

Edit: If the brakes are locking on when the bike is not being used, then it's possible that one of the pistons in the caliper is stuck - this can happen quite easily (as I discovered in my frustration) if the pistons aren't pressed into their respective housings correctly.. too much pressure pushing on one side of the piston and it'll jam up. I'd check the adjustment first of all though and re-bleed with the lever off.

Good luck!

Edited June 10, 201610 yr by trialsguy8

think I have got somewhere now stripped caliper pistons out and drained master cylinder cleaned and rebuild little bits of dirt in the bore behind the piston bled system have a lever now and not sticking just lever is a bit soft is that just a case of adjusting the pull at the lever or something else thanks for all the help on this

Glad you're getting somewhere

If it's soft as in spongy, it probably has air in the system still. Bleed it through some more, I use a piece of clear plastic tubing wedged over the bleed nipple (bought from an aquatics shop lol) - that way you'll be able to see any air bubbles coming out.. Give the hose a tap with the 10mm Spanner you most likely have in your hand, this will help get rid of any small pockets of air whilst bleeding.

I need to do the same thing with mine tomorrow as it's still a bit soft n spongy, got a trial on Sunday

OK will try that I had thought it could still be air just glad I am getting somewhere good luck with your trial I am really new to it just getting practice at the moment