Vacuum ? hose from trans

I have searched the forums without any luck with this. There is was looks like a vacuum hose that is bolted to the top passenger side bellhousing inverted torx bolt. It has a curved metal hose on a bracket that the bolt holds in place, but nothing connected to it. Where does this connect, or is it just a vent hose? It looks like to goes down to the trans, maybe to a modulator?

Also, anyone know where I can find a complete vacuum diagram. The ones I have seen don't include all hoses (such as trans, vacuum ball, cruise, etc).

Thanks.

this is a tube the should be extended into the engine bay with a dipstick and filling tube for the tranny,

transfercase vent hose.

So it's just a vent tube, terminates at the metal tube? Just want to make sure it doesn't connect to anything. Trying for finish installing the rebuild motor, had this tube there and didn't remember unhooking it.