My mechanic has advised that I replace my a/c evaporator. The system isn't cooling and you can smell a foul odor in the car with the freon leaking from the evaporator. I replaced the compressor, drier and other components two summers ago. I've been putting off replacing the evaporator because I'm worried that removing the dash will cause other problems (rattles, misalignments of somesort, other "minor" annoyances). But with all of the freon now out of the system and the Middle Georgia heat taking its toll on me, I'm thinking I should go ahead and do it. Anyone done this? Good or bad results?

I can barely remember a time when my A/C blew cold so perhaps it will be worth it! It's a 1985 300D Turbo with 265K. Other than A/C and a few minor things here and there, runs like a dream and is in tip-top shape. She's my daily driver and I want to keep her in near-perfect condition.

I would suggest that you have the Factory Shop Manual for your car before you start this job. It can be done but it will be quicker if you are methodical about marking lines and keeping fasteners in small marked boxes with good notes... and in the order which you take it apart...

Are you sure it is the evaporator leaking the freon and not the connection with the expansion valve ? That would sure be easier to fix !

Are you going to get a new one or a used one to replace it if you need to ? Be sure to pressure test either way... what a bummer it would be to get it all back together only to find the new one had a leak also....

PS, you can not smell the freon. You may smell algae and fungus in your evaporator box.... you might try an immediate spraying of Lysol spray disinfectant into the intake opening with the motor running .. several light sprayings over a couple of days may cure the smell and you need to be sure your water drain out of that box is "perfect" to use the FSM word....
After you have killed the growing things then spraying with Febreez may be helpful...

I probably won't tackle this one myself. My patience is much too thin for that kind of detail work and my tools/work area are too limited. I'm stuck doing only the basic, simple stuff, unfortunately. I would love to be able to do more.

I'll have the mechanic check for the things you mentioned. And I'll try the Lysol and Febreeze, as well as checking the drains. Thanks!

Which mechanic are you using Shep. I use a good, small independent a/c shop off of 247 north of Warner Robins and would suggest taking it to him to give you a second opinion. Like mentioned earlier it is not hard to check out the expansion valve area for leaks.

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Jim

I use Deaton Automotive in Macon. Both techs are factory trained MB guys who used to work at Jackson MB in Macon. I trust them and they do a great job. I'm just looking for a way -- any way, at this point! -- to avoid the big bucks it will take for them to remove the dash and replace the evaporator. I had the freon recharged two summers ago and there is still a good amount in there so I really wonder where the leak is and how much it is actually leaking. I also wonder if it could just be as simple as the push button unit, which is in "weak" condition, at best. That I can replace myself and will before I do anything else.

Which a/c shop on 247? I work downtown Macon so it's nothing to zip out Seven Bridges Road to a shop on 247. Before or after the base coming from Macon?

Thanks, Jim!

I have the guys card at work and will post it tomorrow. It is out 247 fairly close to Warner Robins. It is a one man independent shop. The guys name is David and he is honest and does a good job. Stay away from AutoAir of Macon.

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Jim

Thanks, Jim. I'll look for your post tomorrow.

I stay away from most shops in Macon except Deaton. They are all notoriously rotten, especially when it comes to MB and diesels.

I'm also going to try a new auxiliary fan relay switch. I noticed that the fan doesn't come on, even when the compressor's on and the engine temp is 90+. That may be part of the problem, as well.

Jackson MB redid the compressor and the drier three years ago. It hasn't worked right since. When I picked it up from them and told them it didn't seem very cold, the tech actually said to me, "Well, you can't expect much. This is a very old car." Arrgghh!

Thanks for all of your help.

The a/c shop is "Cars" and is located at 9201 Hawkinsville Rd. Phone is (478) 785-8686 - David Hawkins. This guy can help you with the a/c part of it and tell you what all is going on with it. Email me and I will give you my phone # get in touch and we can discuss. I have never used any of the shops in Macon but have heard some positive things about Deaton.

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Jim

From a post dated July 2002
http://www.peachparts.com/shopforum/newreply.php?action=newreply&threadid=41539

I am experiencing the same problem on my '85 300D. A dye test shows leakage at the evaporator fittings (suction and return) where they attach to expansion valve. Is it possible to repair/replace these fittings? The metal evaporator lines are OK. New "O" rings, expansion valve have not helped. Both hoses at the bottom of expansion valve are new, show no signs of leakage. There is no dye in the drain lines.
R & R of the evaporator may be the only option.
Alan

Shep,

I hope my post does not offend you. I am only trying to help you take the correct approach.

Some of the things you said, reminded me of a joke that I heard when I was a very small child, I think I read it on a double bubble cartoon that came wrapped around bubble gum in those days.

The joke goes; Someone is looking around under a street light. Someone else comes up and asks what they are looking for. The person responds saying that they lost a quarter. The other person starts looking around and asks "where did you lose it? The other person turns and points and says they lost it in the middle of the block. The helper asks "so why are you looking for it here?" The first person responds "because the light is better here."

If you suspect that the evaporator is leaking, it sounds like you are looking where the light is better. I understand totally why you hesitate to change the evaporator. It is a BIG, patience testing job. But, don't do ANYTHING until you PROPERLY DIAGNOSE.

Since the system will hold refrigerant for awhile it would be very simple to CONFIRM that the evap is the problem. You do this by putting in UV dye. After the dye is in the system and it is charged enough to work. Run the a/c enough for it to drain condensation water on the driveway. Shine a black light under the car at the water. If there is UV dye in the condensation drain water, then the problem is indeed the evaporator. If it is NOT leaking at the evaporator, the black light will show you where it IS leaking.

The key here is diagnosis. As the possible problem becomes more expensive and more serious, proper diagnosis becomes extremely important. Don't go into such things blind. Diagnose thorougly and properly.

I hope I did not offend. I was only trying to impress my point on you, thus providing help.

Have a great day,

Talking about dredging up an old post. Since last posting I have learned how to do all my own work on a/c systems and haev purchased the tools/equipment to do it. Wonder what happened with Jason?

Pulling the dash to get to the evaporator on a W123 is not really that bad for a competent diy'er. Getting the evaporator in/out of the a/c housing is actually harder than the dash removal/installation in my opinion.

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Jim

Jim,

I responded and didn't even notice the date. It wasn't the first time I had my head where the sun don't shine.

Have a great day,