Hi, my '94 C 280 has a vacuum leak behind the glove box where all the climate control hoses connect. It only leaks when i have the AC on 0 or.. in other words off. The vacuum runs in the trunk at constant intervals trying to create a vacuum. After about a half hour of driving it either gives up or finally achieves the vacuum. Can anyone tell me which line its trying to create a vacuum on when the air is off. i feel that finding which one its is and replacing it should fix the problem, I just cant tell which one the leak is coming from. Any other ideas are greatly appreciated.

 

also if anyone could give me any pictures or diagrams or even directions on how to open the air distribution box? i've learned not to just pull on the hoses...