I'm back again and ready for more abuse(from this car that is). I need to replace the expansion value and one other part of the A/C system before I charge it back up and see if the compressor is any good. In the MB manual I purchased it says the first step besides draining the A/C system, which I assume means removing the freon, is the remove cover at right under instrument panel. It then lists a group and instruction number. The problem is this specific instruction is not listed under that group. Nice job Mercedes. Anyway can anyone explain to me where this cover they are referring to is. Thank you in advance.

David

 

124?

i thought the expansion valve was just on the firewall of engine compartment...a little bit on the driver's side.

 

It's a 123 and the service manual makes it seem like this compartment is on the interior. It has the same naming convenion as the interior subgroup.

 

I also thought that the expansion valve on your model is near the firewall, and should be accessible from under the hood. so I am not clear what you are trying to accomplish by removing panels within the interior of the car.

What other part do you need to change, and why?


Phil

 

Ok, I have looked under that compartment that it said to in the manual to no avail. I can't find the expansion valve. Also I am supposed to replace the receiver dyhydrator. That is what the service records said that it would take to fix the A/C system. In the MB manual it say to replace this also if there is contamination. Help!

 

I am still not clear as to why you are looking inside the cabin for the expansion valve, and the receiver dryer (Dehydrator). Both of these components are located in the engine compartment. I used to own an 84 300D, and if I remember correctly, the receiver dryer, is behind the right (passenger side) front headlight. Follow the long AC hose. The expansion valve should be near the firewall.

Below is a site that sells these components and has the pictures of these components for you specific model. I have never dealt with them, so I am just sending you this as a reference. Their Web Address is: http://www.autopartsworld.com/

I agree. It is a good idea, and sometimes necessary, to change the receive/dryer when you open-up the AC system. Its a relatively inexpensive part.

Phil

 

OK, got both of those parts out. The expansion valve is truly in the passenge compartment under the glove box when you remove that panel. I followed the line back from the receiver dyhydrator and that is where it led to. Now when I put them back the manual was saying to lubricate the threads with cold flowing oil. What type if oil should I use?

Also when I get the sysyem put back together can I charge it. I don't have any guages and knowledge of that process. I also need to flush the system with refridgerant it says. I don't have any freon also. Should I just take it somewhere and have them perform these tasks. Thank you.

David

 

In order to charge the system, you must first "Pull Vacuum" for at least 45-Min. To do this you will need a special AC vacuum pump, as well as pressure gauges. Only than can you charge the system. A vacuum test will also uncover most AC leaks if there are still any.

Take it to a Pro. and make sure that he fills it with the right amount of Freon and Oil. The quantity required should be marked on a sticker in the engine compartment, as well as in the owner's manual.


Phil

 

Hooray. I have A/C. Replaced both the expansion valve, receiver drier and all the o-rings. Took it over to have it charged. They added freon and said that there did not look like any leaks. A/C runs good. On to the next issue. Thanks to Phil!