Can the sliders in the calipers be freed up with some good lubrication or be replaced without swapping the entire caliper? The piston is working fine and there are no fluid leaks, but one slider is causing problems. I can hammer on it and get separation to get the caliper back on the rotor, but it would be nice if it would have some movement without the sledge or replacing the whole thing.

Any suggestions?

are you talking about guide rods?

You can easily change them by new one.

You can find some info here:   http://www.hmaservice.com/webtech/