1988 Fiero 4 Cylinder Clutch Diagnosis?

[Clyde Frog]

Ok, I explained this problem to a few guys on a fiero group on facebook, and they told me to replace the master and slave clutch cylinders. I have already purchased them but I'm waiting for this weekend to install them. Ok here's whats goin on.

I have to press the clutch a couple times before it'll shift. If i leave my clutch in at a stop when its in gear, it feels like the clutch is disengaging and the car will move or die. The engine runs fine in neutral or while driving. Also, I noticed the fluid in the master cylinder resivior was low (I just purchased it 2 weeks ago) so I added it. Today it was harder to shift tham usual so I checked the fluid level again and it was nearly empty. I topped it off again and took it for a little drive and checked it again, it hadn't lost much fluid. I also noticed the fluid is really dirty. I'm wondering is there is possibly a leak in the line...I checked both the master amd slave and didn't notice any fluids leaking from them. Suggestions?