280C Center Vent Won't Close
 

My 280C's center vent allows air to enter the cabin, even in the fully closed position. This is not OK on cold winter days. Has anyone addressed this problem? Is it an under-dash, or under-cowl repair?

TIA

Have you already tried adjusting the control rod screw (the big philips screw you can see through the vent louvers) that connects the lever to the flap, to make sure the vent IS fully closed?
If it's not a control adjustment problem, the flap edge is lined with some type of seal material, rubber I think. It's mounted in the upper air plenum, just downstream of the heater blower. I've never tried to repair one but I suspect you might have to remove the air plenum to fix it. I looked in my W114 manuals and it looks like the AC case and possibly the heater box has to come out - pretty much the same ordeal as replacing the heater blower! Or you could remove the dash louver and tape some plastic over the mouth of the duct.

Happy Motoring, Mark

That was easy ...
 

Move the lever to the closed position and tighten the screw until a little resistance is felt. There was about a 1/8" gap that I could see closing as I turned the screw.

Thanks - no more cold air.