Seems like it might be a lot easier to go down in the left body gear well and simply top off the resorvoir.
Seems like:
a) a waste of fluid
b) messy and dangerous (if you spill it on sensitive body parts)
c) you would have to drain the overfilled system
d) a waste of time walking to the store 500 meters away to get fluid and a handpump
e) you don't get to stay dry and warm in the cockpit
So what are the advantages of your method?
