I think I broke a cylinder

I have a '67 Ford 4500 TLB. I was digging today when I heard a pop come from the boom. Looks like there is something wrong with the crowd cylinder system. The stick no longer moves - more accurately, the rod no longer moves. When I worked the lever, I heard what sounds like oil moving through the system under the deck. I don't see any new leaks or oil gushing from anyplace. Think something inside the cylinder broke? The pins don't look broken, and the cylinder isn't out of place.

I think I broke a cylinder