dorman/4x4 vaccum actuator?

ok so there are a couple of people looking in to this for me and i'm grateful, but i thought i would spread it out a little further and see what we can figure out,i know what the part does and how it operates. what i don't know is how the vac lines and one way checkvalves are placed,located,ran, etc, etc, someone told me they run from the axle where its located to the tcase then to the firewall on a vaccum block of some sort but since mine are gone lol i have no idea's, vac line and oneway checkvalves are cheap so this should be easy to fix but i don't want to screw things up more than they already are:confused: i know a misplaced vac line can make me run shotty so if ya have any idea's and or pics please throw them at the back of my head like a snowball with a rock stuffed inside thanx