Clutch drag

[Grumpy Goat]

My clutch is dragging. I’ve suspected it for a while and yesterday I tried turning the rear wheel by hand in 1st gear with the clutch disengaged. It’s much harder than in should be. 
...
I’m going to remove the starter motor and bleed/flush the hydraulics, hopefully today if I can find some suitable mineral oil.

Peter,

This is the first I've heard of this being reported, and am interested to know what you find. I think that your approach makes sense since it could be that somehow you have air in the system. With air in the system the hydraulic pressure would be less, leading to less effective disengagement. Question then is ..0 did air get in the system in the first place. Maybe some seals are going ...?

Looks like this is the fluid you need.