[mttandrsn offline]

I'm looking at buying a set of Shimano XT brakes on Craigslist, model BR-M765 from a 2005 bike, but the guy selling them says there is a problem with the rear brake: "The rear brake barely moves the caliper piston. It acts like it needs to be bled, but I tried that and it seems to be well bled. I'm not really sure where the problem lies." Does this ring a bell with anybody? He wants $45 for both of them, so I figure even if it is a big problem I'll still get a good front brake for cheap.

Thanks!

[maddslacker offline]

There is probably dirt and grime caked around the piston preventing it from moving. It could be that it just needs a good cleaning, or it could be stuck for good.

[jwh321 offline]

Take a good look at the other end, too. You may find a problem with the lever/reservoir, or perhaps even a clogged line. I've seen one that had the opening partially covered where the line connects to the reservoir body. It looked like some metal shavings, perhaps from the manufacturing process and it got acros the top of the little brass insert and partially blocked it.

[element22]

Agreed... The caliper is more than likely very dirty and need of service. More than likely the calipers pistons are sticking.. A fix is to cycle the brakes till the pads nearly touch each other. Using the spacing tool that comes with the brakes push the pads back and cycle it again a few times. this will help lubricate the piston seals and loosen things up again..If it doesn't then the caliper is in need of a rebuild...Could cost extra dollars...