That hose doesn't just pop off like that from the manifold. Chances are you broke that nipple and to fix it, It's not going to be fun. Either you buy a new manifold or like others stated JB weld it in place. Getting to that nipple to JB weld it is Another story as its requires you to take off a couple of parts to get a clear look at that nipple.
917-939-4980 CODING E and F Series New York Area