Ford 3000 3 point wont lift

[Jeff Gammon]

1968 Ford 3000 3 point wont lift. Pump is working. I have replaced the safety valve, relief valve, prongs under hydraulic cover but still no lift. With the cover off I am not getting any pressure to the block off plate on the hydraulic lift cover. I have checked the control valve and have pulled the dump valve out and both operate smoothly. Should the dump valve have an o ring on it. Mine dont. If it dosent would that cause me to not have any lift at all or oil going to the blank off plate? I have hat the top plate off 5 times and this is the only thing I can think of. Any help would be appreicated

 

[Mike(NEOhio)]

Been a while since I was into mine but IRRC that valve should have a cast iron ring, split so it can go on. The system will not show much pressure without a load on the hitch.