Originally Posted by mcoomer

Sticky pistons with no leaks? Easy to fix. Unless they're totally corroded or the system is shot a good inspection, clean, and lube should get your brake calipers back in shape.

Remove the caliper and take the pads out. Squeeze the brake lever slowly so that the pistons are forced out nearly all the way. Take a look at the piston and take a stiff brush to any rough stuff. After that dribble a few drops of brake fluid, mineral oil, Tri-Flow, or similar on the pistons. Force the pistons back into the caliper and repeat. Once you've done this two or three times put the pads back in, remount the caliper, center it on the rotor, then check to see if the pistons are sticking. Probably not a bad idea to bleed the calipers and bleed and fill the master cylinder as well at this point. You should be good to go after that and the only thing you spent was a few drops of whatever you decided to use on the pistons.

Mike