Are you sure it's the caliper and not the brake pad (or pads) themselves. My pads on my pickup were sticking because they weren't free floating due to rust buildup underneath the silver clips. I'd hit the brakes and they'd stay stuck for a short distance then release. I ended up putting brake lube on the tabs where the pads slide and that didn't help. I had to pull the calipers off, then pull off the caliper clamps. I removed the silver clips, used a dremmel tool with a pointed grinder and cleaned the slots to the bare metal. Don't take too much off the inside walls of the slots or the new silver clips won't hold well and you will have to bend them in slightly so they clip on tight. Once my new clips were in, I slide my brake shoes back into the caliper clamp before installing them on the car to make sure they floated freely. When I knew they were floating correctly and the new clips weren't going to come loose, I put the whole set up back together and nothing sticks at all any more. Check this out before spending all sorts of cash on new calipers or messing with brake lines. Cheap fix too. Hope that helps.
