Vacuum leaks behind dash
 

99 Xj sport, 255,000 w 4.0. this morning I made a cheap smoke machine and found the last vacuum leak, I think, under the hood. My question is if anyone knows where I might have leaks behind the dash, do you guys think I should remove the dash and do the cigar test again? I don’t think I smelled any cigar smoke in the cab but after I got done Had doors open and not sure exactly... Curious on anybody’s thoughts.... been chasing a high idle

There are only 2 places under the dash that you may have a vacuum leak. One is the heater control and the other is the brake booster. You can check the heater by applying your smoke directly to the vacuum supply hose after pulling it off the manifold and watching under the dash. You can check the brake booster by pulling the check valve on the drum and applying your smoke to the drum, watching around the brake pedal shaft in the cabin. Apply pressure and move the pedal with your hand to make sure as well.

Thanks, going to get to this today. ITs been a serious job bringing this thing back