The vehicle is a 420 SEL, W126, 1986 version. I have a leak in the a/c system, still using R-12, which is getting progressively worse and I've got to start chasing the source,without knowing where to start.

In searching the archives, there are a number of stories about failed a/c evaporators and the horrors of having to remove the dash for replacement. I'm of the impression it's even a nightmare to replace an expansion valve.

I've owned numerous automobiles, both foreign and domestic, and I've never experienced a failed evaporator. It makes me wonder if somewhere along the line, Mercedes produced a poor design.

I would appreciate knowing if the evaporator failures are mostly associated with one particular model and year and how susceptible the 1986, 420 SEL might be to this problem, whatever is causing it.

William