Originally Posted by mlhelfin
Okay fine UNIBLURB, sounds like you've been there. It's definately in that area. I probably need to start under the battery tray and work my way back. That line running through the firewall into the interior looks like it might be an 1/8" line. Is that the one running my HVAC controls ?
Don't know if the 95 is exactly the same as a 96 but since my ZJ was built late 95 I bet it is. Yeah, have had to replace the AC evaporators/heater cores in my ZJ, and wife's TJ, so kind of familiar with what's behind he dash. Also have had to repair a vaccum leak in the same area you're talking about.
I would start where you hear the leak instead of tracing the whole line. There's a vaccum line going across the top part of the outside firewall with a "T" in it. The main black (yeah, 1/8") plastic line T's off and goes through the firewall next to the line. This is the main feed for the whole control knob. And as mentioned before it turns towards the control unit behind the left part of the glovebox opening.
About all you need to do is look under the bottom part of the dash and start taking screws out. Try to just take the ones out which are holding the plastic dash on and not the ones holding the metal part of the dash to the metal framing. I use an electric drill for this type of work since there's quite a few screws. But you can't get to them all using a drill. Also there's some holding the glove box in. There's a phillips screw over by the door jam you need to use a short phillips on with the door all the way open. You'll probably also have to pry out slightly on the plastic part of the dash to get some of the metal clips to break loose. The lower half of the plastic dash may not want to detach itself from the left side where the dash stick out. But it will be loose enough where you can work around it. There may also be some vent tubes you will have to move out of the way or disconnect.
I've also taken out the whole HVAC control unit part way out of the front of the dash many times. You can only pull it out so far because the vacuum/electric lines don't have enough slack in them. There's only about 3-4 screws holding the trim/front around this (along with radio) and the rest are all clips. There's a screw hidden behind the ashtray and you need to remove it to get to it. You may not even need to go there if you find the leak behind the glove box and repair it.
Most say to disconnect the battery before even starting to remove dash parts in this area. The air bag is right behind the dash above the glove box. I'll typically disconnect the battery a couple hours before starting to remove dash parts since supposedly the air bag may hold a charge. But once you get the glove box removed you will need to connect the battery/start it to find the vacuum leak. Once repaired it's a good idea to disconnect the battery again before you start hitting the dash parts to snap the clips back in.
Good luck and shout if you need any other info.
edit: I should mention, what do you splice a broken/cracked vacuum line with? Most say you should replace all the vacuum lines if brittle. But if you don't know what you're doing this may not be the best route especially when you get into the back of the vacuum line switch.
My vacuum lines weren't all that brittle and the auto parts stores didn't sell a coupling that small for those tiny vacuum lines. While maybe sounding like a rig-job I took an old Bic pen, broke it, and used a short empty section of the tube which holds the ink. It fit tight right into the inside of the lines and then put a good electrical tape (Scotch 33) on the outside with the lines butted together. Make sure you use a sharp razor knife when cutting the lines/tubes or you will crimp them if using sidecuts/dikes. Did this repair about 1 1/2 years ago, hasn't leaked since, and the ink tube does not restrict the vacuum since all my blend doors work great.