Brake fluid coming from back of caliper - can it be fixed or am I looking at new calipers?

So I just discovered a nasty leak coming from the back of one of my calipers. As far as I can tell, the leak is coming from where the ebrake bolts into the piston. I didn't see any fluid on any of the lines, or anywhere above that bolt - and that bolt was soaked. Seems most likely that there's a seal in there that's been compromised. Is this something that's fixable, or am I best off just putting a new caliper on it?this is the best picture of the caliper I could get. via /r/cars http://ift.tt/2sVt4j7