Incase someone ends up here. I Rigging up an electric motor to turn the hydraulic system wile I traced the air leak out on our 440B Farmboy Bobcat. I replaced the pintal seals ( KOA 16253-214) and the o-rings in the bottom of the pintal shaves . At this time I replaced all the hoses going to the pump , including the line that t's in from the filter. Still had air . Next I replaced the hydraulic pump seals and the shaft seal behind the belt drive.(NOK 16253-16NC)Works like new now , I am running John Deere hyguard hyd oil and life is good !I hope this helps someone in the future