[Roadsters] Clutch question

[steb]

Got the Datsun running yesterday thinking that we most likely won't get
anymore snow here in Wisconsin? When I tried to engage the clutch I had
no pedal action at all.
I drained all of the old fluid from the system and used an air hose to
blow out the lines. I install the bleed screws, filled the system but
wasn't able to get any fluid into the system for bleeding. I noticed
that the actuator on the firewall doesn't have a bleed screw on it as
opposed to the brake system which does have bleed screws. There is a
plug installed on the bottom of the actuator however. What is this plug
used for? Any hints on what I'm doing wrong are appreciated. 
 
Steve