Zoltan,
               I had clutch functional weirdness a couple times over the
years. The first was a pilot bearing failure. The clutch
shaft was jammed into the crankshaft with the broken bits
from the bearing. I was a rookie vanagon owner then and
didn't know what was going on  until I pulled the tranny
and discovered the problem.
               The second time it happened, it turned out  a spring from
the clutch friction plate had broken and its bits and
pieces were jamming up the mechanism. I couldn't get a full
clutch stroke as you describe. Again I didn't know what was
happening until I pulled the tranny which is not too nasty
a job in a 2WD, much more trouble in a Syncro IMO. Anyway
hope this helps.
Rick