A/C Evaporator for a 300e (124)
 

I found out this week that the evaporator in my '87 300e is bad and this is where the freon and some compressor oil is leaking out. I about choked when my mechanic told me that the job is approx 14 hours and includes removing the dash. He also told me that a MB evaporator is about $900.

Has anyone ever replaced their evaporator with a non MB part? I found one online made by ACM w/ valve and it says OE for $200. Will this work, and if so, why is the price so far off the MB part?

Should I replace the heater core while I have it out of the car? Any other sugestions would be a big help. Thanks in advance.

Go with the ACM it is a much better evaporator. Dont worry about the heater core, never replaced one due to leaks. Replace all of your actuators while you are in there, there is about 6 or so fastlane can get these for you. Evaporator replacement for a DIYer shouldnt be hard if you rank 6 or above on a scale of 1-10 for a DIYer. :D

euro 287, Thanks for the reply.
Where is the best place to find out the instructions on how to do this task? I would like to read what is required before I decide if I want to tackle this project. Removing the dash kind of scares me...

Been there, done that (that is, had it done). Definitely use an aftermarket. Make sure it's all copper. The aluminum factory ones were the ones that corroded.

In my opinion, not a DIY project. It is very involved and not for the faint of heart. Best to find an independent in your area who has done a number of these as there are some tricks.

Somewhere on the site someone posted pictures of their dash disassembled. Not a pretty picture!

I did it and I am a DIY'er!
 

My first recommendation would be: buy the manuals! It is the BEST investment you can do if you plan to keep your car for a while.
If you can live without your car for 1-2 weeks (depending on our pace), you can do it! and save BIG $$$$$. However, it is physically a very HARD job.
Before starting I went to a MB independant and "evacuated" the freon. Then, I replaced the evaporator myself along with the actuators, the reciever drier and the expansion valve. After that, I took it back to a MB independant to change over to r134. The r134 does NOT cool down as good as the R12 specially at idle but, it does the job (I live in Florida). Keep in mind that the AC system in the early 300e was not designed for r134 plus it is NOT the best design in the world to begin with.
I used an after market copper evaporator. I don't remember the brand. No problems since the replacement.
As far as the job itself, you are not only going to remove the dash but, you have to remove the AC blower assembly, which is done from the engine side. Some of these instructions are NOT in the manuals.
If you are NOT mechanically inclined, pay your mechanic to replace it for you and do the change over r134 at the same time.
You will be glad you did!
:cool: :cool:

There are a lot of posts on this topic. FWIW the consensus seems to be that this is something best done by a shop and a tech that does a lot of these repairs. Sort of like open heart surgery.

I converted my 300E to R134, and cooling has been OK for Virginia summers.

On a 126 (different, I know, but similar enough) the book calls for 17.9 hrs. labor for evaporator replacement. FWIW

Just to save anyone anytime when removing evaprorator the only thing from under the hood to do is disconneect heater lines , disconnect blower motor plug and push gromett through firewall, when removing case disconnect outside air temp sensor. This way you dont have to remove anything as for blower motor assy. :D