Probably gonna have to wait for RickB to answer this one.. I'm not at all remotely familiar with the industrials.
While I'm at it.. I can reccomend that you may want to get a manual for your machine.
Going out on a limb here.. but I went to the CNH parts site, and looking under 555 3 cyl TLB, and PS/Front axle, and PS pump and resv, I found this diagram.. which looks like a pretty common ford PS pump/integral resvoir...
has a fill cap.. and a filter in there.
if this matches your equipment... you found it..
soundguy