Filling hydraulic fluid and other questions

I've got a 1948 Case SC. Hydraulic pump is located on the rear below the PTO. (Picture URL attached) There is a screw out plug for the trans. There is also a pipe coming up from the hydraulic pump with a screw on plug. The pump itself has what looks like a screw-on cap on top but when I try to unscrew it, it hits a flat metal bracket that surrounds the PTO (not the sheild).

Some questions: Where do I fill the hydraulic fluid? When filling the hydraulics am I also filling the trans? When I raise the bucket, it only goes up about 4in and then slows to a stop. If I pull the lever again, it will go up another 4in and slow to a stop. Am I losing pressure somewhere? I can see fluid leaking from the lever mechanism on top of the pump. Is that enough to do it?