I have a '82 240D with factory a/c. Yesterday, I was trying to diagnose a vacuum leak that has occured ever since I purchased the car a couple of months ago. I believe I have found it. From the engine compartment, I traced a brown vacuum line that would not hold vacuum. I took the bottom kick panel that surrounds the brake pedal so I could see where the line lead to in the passenger compartment and found out it leads to no where; the line was just sitting just beside the brake pedal with a rubber nipple at the end like as though it was connected at one time to a fitting.
I found out through this forum that the brown vacuum line is for the climate control system. My car has the three manual rotary controls. Two conrol temperature (manual cables to adjust coolant to the heater) and one control for fan speed. Also, along the rocker panel switches (for antenna, sunroof, etc) there is the vertically mounted a/c control wheel (to adjust the a/c temperature).
I tried to locate where that brown line connects to but could not find where it would go. At first I thought the vacuum line may mount on to the vertically mounted a/c control wheel but there is no vacuum line connection there to receive a vacuum line. I did check the recirculating vacuum flap actuator just above the fan area; it had a green vacuum line with yellow striping connected to it and it is working properly.
I was wondering if the MB techs or anybody in the forum could help me with this problem of locating where exactly does the brown vacuum line lead to. Many Thanks