While the dash is out I would replace all the vacuum elements to the Ac system. They can be done with the dash in, but a difficult job.


http://www.peachparts.com/Wikka/W123HVACVacuumActuators

If money is a factor Just replace the center vent element, it is the most difficult. All others can be done with the dash installed with just a bit of difficulty, but no where near the amount of cuts and swearing as with the center vent element.

Evaporator drain tube.

Check all grounds, clean and reattach then seal.

Temp sensor foam tube but do it with a hard plastic tube, it will last forever.

Dave

__________________
1970 220D, owned 1980-1990
1980 240D, owned 1990-1992
1982 300TD, owned 1992-1993
1986 300SDL, owned 1993-2004
1999 E300, owned 1999-2003
1982 300TD, 213,880mi, owned since Nov 18, 1991- Aug 4, 2010 SOLD
1988 560SL, 100,000mi, owned since 1995
1965 Mustang Fastback Mileage Unknown(My sons)
1983 240D, 176,000mi (My daughers) owned since 2004
2007 Honda Accord EX-L I4 auto, the new daily driver
1985 300D 264,000mi Son's new daily driver.(sold)
2008 Hyundai Tiberon. Daughters new car