I have a 1973 140 skeleton that I trade for 2 fenders off a 1966 RF parts tractor. The 140 consists of frame, front axle w/wheels, and hydro unit. No engine, hood, grille or pan. Hydraulic lines are intact. Here's my question, is there any way to check or test hydro unit to see if it is any good? Was hoping this could be a backup hydro for my 300 or my 314. Any ideas out there?