Ok, I've been working on vehicles my whole life, and I am ashamed to say, I have never had to work on a vacuum system and don't even know where to start. I have a 99 XJ, it has all the tell-tale signs of having cruise, bt the cruise doesn't work. I wanna check vac before I start taking stuff apart, but I don't even know where to begin. I have the 4.0 I6, so if anyone can help out, cause I can't find any help in the haynes manual and I don't have the extra $ to buy the FSM. This is my first Jeep, so be gentle, explain it like you would to a woman, please. :helpme: