I know I am late to the topic, but if I understand your reference to the hydralic function, you are refering that your 3 point hitch has no down pressure. If that is the statement you are making this would be absolutely correct and what what you want to happen. It is true of even very large commercial farm tractors. Down pressure on your 3 ph will do one of 2 things, neither of which you want. 1 remove traction from rear wheels as you could easily lift the rear of the tractor with down pressure. The second would be to break someting in the system. Since on these small tractors almost always the lift cylinders for the 3ph are internal to the tractor this means a complete differential teardown to repair. Also replacing a control valve is inlikely as it is internal to the tractor also. Cables and/or linkages and the control lever are all that you will locate outside of the differential housing.
That all said, for the addition of a loader, you will need a supply, pressurize line and a return, unpressurized line for the loaded and 3 ph to operate. I do not know your tractor so it is posdible that you may have a port system that allows for these connections.
Hope this is helpful, as some of the comments seemed to address external hydraulic cylinders and not the 3 ph.