I was going ahead and changing the fluid to take care of the 'air' problem....it's not happening today!
After I pulled the reservoir cap it was virtually empty! The sight glass appeared full but was actually covered in grey sludge. The bottom fourth of the reservoir had sludge....where in the world did it come from? I am almost fanatic about maintenance but this hit me like a brick. Loss of almost all of the clutch, sludge & no fluid. I am thinking a leak allowed dirt into the system & built up over time. This weekend I plan to pull the clutch slave & replace the seal, clean the reservoir & replace the clutch line.
Suggestions? Anyone ever seen this reservoir sludge buildup before? thanks