a/c evaporator in 85 300d
 

my mechanic is working on my a/c and there is a possibility that the a/c evaporator is out. He is an awesome mechanic very good customer service. I was wondering is this common or very rare. Has anyone had this go out on them?

124's seem to have trouble with them, but I didn't think it was a common 123 complaint.

For my W210, there is a tool available to test the evaporator for leaks without removal. It bolts in place of the expansion valve to allow charging with high-pressure nitrogen. If such a tool is not available for the 123, you could make one out of an old expansion valve.

anybody

Evaporator
 

I have a leaking evaporator, it is somewhat common. What isn't as common is the cost of replacing one. The dash, center column, heater core and everything south of the firewall has to come off. Many old clips, vacuum actuators, plastic tabs WILL break. There are a list of service items on this web site that should be done if you are doing the evaporator. I don't know where the link is, but search for evaporator, and there will be a link to a photo step-by-step DIY. My mechanic demured on the repair, saying if he did it, it would cost $2k.

Hope that educates and pertrifies!

Couldn't you just add a tracer dye, set a pan under the evaporator drain, and check the water with a UV light to see if the evaporator is leaking?

Scott

You probably can't get a false positive this way, but the chance for a false negative is very high.

Pressure-testing the evaporator will tell you for sure if it is leaking.

It's common.

http://www.peachparts.com/Wikka/W123Evaporator

82 300TD and a 83 240D

While he's at it have him replace the vacuum elements.

Dave