800 Ford Lift Failure

My FIL has a 800 series Ford that he uses to haul cow feed with a 3pt carry all. Lately larger loads have been pushing the old girl to its limits, and I just got word that maybe the limits have been reached. He e-mailed me tonight and said that yesterday, it was slow to lift, and today would not lift a load at all. With the carryall removed, it will pickup the lift arms alone, but no load. Also says it is leaking somewhere under the seat. I haven't yet seen the tractor, I'm 5 minutes from a good Ford dealer for parts, and he's 45 minutes 1-way at his place, so I'd like to take what I'll need to fix it if I can. Any thoughts on what may be the problem? I know on our 4000's we took that cover off, and actually took it to the dealer for repair and adjustment, but looking back, it may have been as much of a time thing, but the required work may be beyond my capabilities, I have never tried, so don't know.

Tractor does not have a hydraulic outlet installed, so can't test pump output that way. I don't have a book here for that one, he has a shop manual for it at his place. Is there a screen or filter for the hydraulic pickup that we should check while we're messing around?

thanks

disregard this...noticed I was in the wrong section. reposted in the Ford forum.