Have a 1982 240D Sedan w/Manual Transmission and full A/C unit that is working properly except for one item. Have noticed that there is no pooling of water underneath this car when engine is turned off and it is parked. There appears to be NO release of condensation from A/C unit through the tube intended for this purpose. Have fully cleared this tube of years of build up from hardened algae et al yet it still is not releasing any condensation from A/C usage.

Have had a lingering leakage problem with water coming into passenger cabin from outside during heavy rain storms. Have fully replaced floor boards in car, replaced weather stripping/seals on doors to minimize water leakage. Yet it now appears that the condensation from A/C unit is slowly leaking back into cabin of car from a/c-heater box mounted behind middle console under the dash rather than through the tube intended for this purpose.
This car is not leaking any anti-freeze.
Is there some kind of sealed vacuum valve underneath the a/c-heater box or a torn/aging gasket around a bolt that might be causing this leakage?
Any thoughts on how to FIX this problem or has anyone experienced a similar phenomenon with their W123 sedan?

 

On my 85 300D, the foam hose that goes from the evaporator box thru the floor panel had rotted off, and all the water from AC was running in the floor. The hose was discontinued from Mercedes, I used the foamed rubber from a ice scraper handle, fastened on by a small zip tie. And has worked for the last 10 years. No more wet floor, but a pain to get on.