Pneumatic + Hydraulic = Pneudraulic, used in position Avionics (flight
control surfaces), where you want the power of  Hydraulics with the
vibration dampening of Pneumatics.  In this instance, too much oil means the
stuff that hits the oil (piston bottoming, oil splasher, ect) ends up
putting air into the oil.  Oil is dense, air is not. So heat connectivity is
minimal when the oil is so high as to make Pneudraulics.
ed- Who learned to spell Pneudraulic after all.

> And I have no idea how "phneudraulic" is meant to be spelled. Never seen a
> word quite like that. It's a darn nice word, I think. Pneumatic and
> Hydraulic are the closest I can come up with.
>
> -- RJS
>