For two years my 190d has been blowing hot air only, and the flaps do not work. I tried a new CCU, but it did not solve my problem. Today I removed the dash to try and find a vacuum leak. I tested vacuum going into the switch over valves unit. The green/brown line comming from the vacuum pump I tested the unit for vacuum and it holds. The red line from the heat control valve it holds vacuum. When I tested the five white plastic hook ups none of them held vacuum. When I took off the lines from the unit and tested them they all held vacuum. Since all the lines after detached from the unit hold vacuum it looks like I don't have a problem there. Also, I noticed that when vacuuum was applied the flaps did move. I'm wondering if the white plastic lines comming out of the unit should hold vacuum. Thanks for your help.

Hugh,, Sr.

1984 190d (W201) 132.432