I had to replace my passenger side bleeder valve because my friend tightened it WAYY too tight. It ended up breaking in half and almost the entire thing was still threaded inside, so I took a dremel and cut a slit in it and then used a flathead to get it out.
I wouldn't replace the whole caliper if thats what your asking. It could also just be a faulty bleeder. You can go to a auto parts store and ask for bleeder screws/valves/etc. I kept asking for bleeder valves and they looked at me like I had an extra chromosome. So I asked for a bleeder screw, and they took me right to them.
Good luck!
-Brian