Hi! I am presently working on this. The valve is located on the passenger side Air intake below he bumper. Its just above the AC pipes, Its black in color, and plastic made.In the maintenance manual it explain you must turn it counterclockwise until it stop, than turn clockwise 1/8 of a turn, than you pull on it. In fact, it will actualy turn 1/4 of a turn, than stop, when you bring it back 1/8, it comes loose a bit, but thats it. This is where I am stuck, I can't pull the darn thing out.Very cramp area to work in, very little valve to. If you look under the bumper where the plug is, you can see where the liquide will come out, its part of the radiator support.I checked on the Jeep Compass Forum
http://www.jeepforum.com/forum/f98/ , and the same Q you ask was there as well, but still no solution.Good luck!
