This hose is not an emmissions hose, correct?
Would you please post a photograph? My manuals "include" Wagoneers as well, although I don't have any.

 

 

Cruiser and I, as well as others know that deal like the back of our hand. Goofy that the "vacuum reservoir" is in the front bumper on the right. A line comes off the intake manifold, back across the firewall, then all the way forward to that ball. (it has check valves and provides vacuum even when the intake vacuum ain't happening.) (It can be relocated almost anywhere) The ball often takes a beating and might be found hanging.

The hard little black line coming back from that into the dash is what the HVAC or whatever uses. The flaps will be on defrost without it, not sure which way the heater water valve rests, but applying vacuum to the valve with the temp lever changes from hot to cold.

"hose broke near where it connects at firewall. Can not find where the other end attaches" The line from the manifold down to the ball is a small rubber "hose", the vac coming back to the dash is a small black tube.
The ball could be split to two halves with two check valves, and two black tubes coming back, but still only one line to the manifold for vacuum. The second is for cruse control, and one goes in to control the HVAC.

 

Here