Vacuum Lines

I have the 86 Comanche with the 2.8 V6 lawn mower engine.
I not getting vacuum the to the front axle thus I have no 4 wheel drive.
Is there suppose to be a can that holds vacuum like on my FSJ? I noticed the lines go from the axle to the top of the firewall and then drop down to a point above the TC. Can anyone give me some tips or perhaps a diagram??

Thanks

86? Not sure. But my 87 XJ has a vacuum cannister inside the front bumper (passenger's side).