Mitsu D3250FD Hydraulic problems 1500 hours

[cooks3743]

I bought a MitsuD3250FD in Jan. All the hydraulics worked fine. It sat in the barn until now. The hydraulics now don't work. I cleaned the screen,changed oil, and tried priming the pump at the intake. No luck. The oil in the tranny is lower than the pump. Does that make a difference? There is no oil leak anywhere. If there is an air block,where would that be located. Intake or pressure line?
Thanks for any help