Have '92 300D. Won't hold freon. I put red dye in system and don't see any external leaks. I smell a "chemical" smell coming out of vents. How do I access the evaporator/expansion valve? I have replaced several blower motors on 201's. This one was making noise last week when I gassed up my system. Is it the same procedure on the 124 as the 201? Thanks for your advice. Ernie

Evaporator replacement requires complete removal of dash and climate control box. Big job, 16 hrs by the book, considerably longer the first time you do it. Blower can be accessed from under the hood, but you must remove the wiper motor and transmission (good time to clean and lubricate the wiper mechanism).

Expansion valve is beside the brake booster toward the centerline of the car.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

I can only hope its NOT the evapoator! Ernie

Ernie,

If you are smelling refrigerant out the vents, it is likely the evaporator. Red dye doesn't do much good. It is difficult to see. You need to use UV dye and then look for it with yellow glasses and a black light.

Once the system has the UV dye and is cooling well enough to make condensation drain water, shine the UV light in the drain water and look for the dye. If it is there, then the evaporator is the culprit.

I was very lucky because I found lots of UV dye at the expansion valve. As psfred said, the expansion valve is on the firewall in the engine compartment next to and behind the brake booster. Just follow the lines.

I have had the dash off almost all the way to the evaporator. It is a time consuming job, but not complicated as long as you have the printouts of the appropriate sections of the MB CD manual. Most of the various fasteners that you deal with are not difficult. While you are in there, you should replace ALL the vacuum pods and the rubber elbows that connect vac lines to them.

If you were to get the CD you can work through this. If you get stuck there are several people here that can help you past the hurdles. The pods and the evaporator will total to about $500 in parts if you buy them from fastlane here on the site. Unless it's been replaced lately, you should probably replace the filter/drier which is about $42. R12 is coming down in cost and can be had for under $15 per pound. I just bought a 30 pound tank for $425 total cost delivered to my door. It might can even be bought cheaper than that.

Good luck,

Thanks Guys, I hope that it is the expansion valve. I'll have to use the uv method. I don't see any red or oily spots. It is still cold in Louisville and it is not going to make condensate! I really don't look forward to removing the dash. I'm 70 or 80 pounds overweight and it will be tough. I love this car and it is probably the overall best car I've ever owned. I doubt I could get much for it anyway with no air. Car has 235K, new tires, radiator, and alternator. 32 mpg and a comfortable car. I drive 500-600 miles per week and I like the comfort. I've had diesels for 21 years and love the economy and dependability of them. Larry this car was fitted with 134 from the factory. Ernie

Ernie,

Oh yes, I forgot. I see 124 and I automatically think R12.

Best of luck with it,

Is there a way to replace the center vent pod without taking the evaporator apart. I have it disconected but can not get it out of the vent not enough room. Conecting rod on pod to door gets in the way. Mario 3

mario,

You won't have to go all the way to the evaporator, but you will have to remove the top of the dash to replace all vac pods except the defroster pod which is just to the left of the glove box. If you remove the dash to replace this pod, you would be oh so wise to replace them all while it's apart. You should also replace the rubber elbows on the pods that have them.

Good luck,