After much help from everybody on this site, I have the hydraulic pump all rebuilt from parts obtained from TM, and looking at the rebuilding instructions here. I have it all bolted back on the Cub (1959 International Cub Lo-Boy with fast hitch), with the pump hand filled with hytran oil as I put it together, and filled after bolted up and the gears turned over by hand to observe it's pumping action and get all the air out of it. I see that there are two allen wrench type plugs on the plate that bolts to the side of the hydraulic controller box. Each one in line with the incoming and outgoing oil tubes from the control box to the pump. These appear to be a means of filling the pump feed tubes with hytran before starting the engine? My question is, whats the proper method of filling the system with hytran before starting the engine? I haven't filled the reservoir yet either.