clutch problem

2007 Tacoma, 4cyl, 2WD,stick. Truck was not started in over a month, it sat in garage during that time. When I started it, clutch pedal went to floor and stayed there, I was able to pull it up and after pumping clutch pedal a few times, it worked ok for a month. Yesterday, same thing happen, pedal went to the floor again, only this time I was not able to drive it clutch not operating. Brake master cylinder is full, checked clutch master cylinder and slave cylinder and and lines , does not appear to be leaking. Is there a separate reservoir located somewhere for this that I am overlooking? Does anyone know where I might find a diagram of clutch mechanism online? Any help is appreciated.