I am going on my fourth Mercedes now. I have a 1995 S420 that I have had for the past few years. I have maintained all the Mercedes I have had myself.

When I first purchased the car, I ran the air conditioning and the air from the vents were room temperature. I immediately thought that the a/c needed to be recharged. It did need to be recharged; but, it also needed and evaporator.

The S-class from 1992-1999 were notorious for having leaky evaporators.
I went ahead and replaced the evaporator after removing the entire dash assembly; including wiring harnesses, pneumatic connections, and air bags. The job took about 3 days to complete. I heard that the Mercedes dealer will charge about $5000 for the repair.

Has anyone else experienced the same situation? I would be more than happy to make any recommendations or provide assistance with replacing one.




Steve

1965 220sb
1970 280S
1982 300SD
1995 S420

 

I have to tackle that issue on my wife 97 C280. probably a bit easier than yours, but I still dread doing that job.

 

Sounds like you have a project ahead of you. I would be more than happy to help you through your project if you wish....I have many of the technical documents if you need them.

 

I doubt there are too many W140s that have not had a compressor or evaporator problem, large or small somewhere along the line in their lives.

In the UK a Mercedes dealer will charge c£2500+ to replace an evaporator. Good independents in the UK can install a fully reconditioned one for less than half that. Used ones can be had (e.g. on eBay) for far less if you want to try/risk it yourself.

I believe that compressors are actually just as notorious for having leaks too in the W140. Problems often start when the aircon is not recharged often enough, or not used at all for 6+ months during the winter. Like the alternator, they are perfectly placed to get damaged by oil if you have a slight head gasket leak too.....

Touch wood, both of mine are ok, but the compressor is a bit nosier these days. Here in the UK it is not really worth having both replaced with new ones, as in many cases that would cost more than the cars are now worth on the second hand market!