Can't find it.

Which line is which on a H belly pump. Pressure out and return that sort of thing. Thanks

Dan,

They're all three pressure ports, all the old cylinders were one-way gravity return. An easy way to connect a return line is remove the fill cap, add a tee and another nipple for the cap. Screw the return hose into the side of the tee. There are pictures of mine on the thread for my Farmall M.

Here's some literature from the era that may be of help...