So today i was riding home from work and realized i had no front brakes. My lever has full play and even when squeezed the whole way nothing happens. I can still roll the bike. The sight glass has a small air bubble, it has been extremely humid in wisconsin also lately. I dont know if those can cause this. Or could this be the spring in the master cylinder. I dont know much about brakes, but i know i need my front haha. Also how difficult is a rebuild if that is what is neccessary. Im planning on changing the brake fluid within the next couple of days i hope thats it. Thanks for the help Mick.