I have a WD with the Allis Chalmers loader, made by "Freeman". When the rams leaked on this, first check to be certain that the four bolts on top of the ram are tightened, since these crush the packing and seal the oil in the ram. If they are already tight, then replace the "Vee Packing".
Remove the ram from the loader, loosen the four bolts on top, then put the cylinder in a large vise and with a pipe wrench unscrew the top of the ram off of the cylinder.
The ram has a large round ring, in a groove on the end of the ram that must be removed before you can slip the top off the bottom of the ram. Once this is done the Vee Packing can be changed and reassembled. If your local AC dealer doesn't carry the packing, any auto parts store that handles hydraulic hoses etc., should be able to order it.
I'm also from Iowa and my local store used to order the packing from a distributor called "Pederson Sells" I believe from around Fort Dodge I think. Any brand will do as long as it has the vee configuration.