I have noticed over the last couple of weeks that my trailer brakes are not working. Today I took the rim and hub off to find out what the problem was. I have never adjusted/tightned up the brakes so I assumed this must be the problem. I turned the adjusting nut and then tried to put the hub back on. I couldn't because the brakes had expanded too much. When I activated the electric brakes I noticed a humming sound, but I noticed that the brake shoes had not moved. What is going on here? I know that they are getting power but why are they not activating? Will they do it when the brake drum (hub) is back on there? How many turns should I adjust the screw on the brakes? This is my first time really messing with these so any help would be appreciated.