Machine ser # is JAF0276653. I put a tee in the pump output line to the loader valve and 0 psi on it until I stroked one of the valves then it managed to climb to a whopping 14 psi @ idle. revv it up a bit and it made it to 20 psi. The outlet line had a tee in it already for adding another hose (guessing to add high flow) owner said when the took that off with it running it had all kinds of oil coming out of it @ a high rate of speed. vehicle drives its just the loader hydraulics that don't function, oh and the Aux pedals didn't really seem to do anything either but the owner said they haven't worked in the 6 years he's owned it. . I could not really see how strong it was driving since the forks were down but I had forward and backwards pretty well. So am I looking at some kind of issue with the pressure relief on the loader valves? maybe something going on with the power beyond setup.
Check your loader valve relief, item 26 in the picture. The drive hydraulics have nothing to do with the loader hydraulics not working. If your loader relief checks out, the next best thing to do is to flow test it. Its just a gear pump that runs your loader hydraulics, and it can get weak or the seals blow out. You probably checked this already, but the splines are ok at the drive coupler? Just make sure they aren't stripped.
Follow up: i put a flow meter in line and had wild fluctuations from .5 to 1.5 gpm. coupler and pump shaft splines were really chewed up. New parts should be here today.
Good to hear you found something.