Since you have fluid at the lines, it does point to the wheel cylinder. Could be full of gunk, perhaps a bad cup or other trash. Getting to it isn't too difficult. Once you pull the drum off, you can remove the shoes to allow access to the wheel cylinder. If your front drums still have the rivets holding them to the hub, you'll need to pull the bearing apart to remove them. Not too difficult, just pop the cap, remove the cotter pin (replace with new), and loosen the nut. Make sure not to let the outer bearing fall out. Rebuilding the wheel cylinder isn't too much different that the mater cylinder.
