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So I live in Cali and I've had a broken air conditioning system for the past 2 summers and I don't think I can stand another summer of 103+ degree weather.
I have a 1985 190E and I've taken the car to a well respected Mercedes mechanic "Silver Star Motors" they said they could fix it but it would be too labor intensive and wouldn't be worth it for the price of the fix.
I now need to try and fix it myself. Does anyone know where there is a tutorial or guidelines for how to take out or fix an air conditioning problem?

Any help would be greatly appreciated
:confused:
 

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The Haynes manual does not cover this topic. What I know of this issue is that it is a big time repair job involving removing the radiator and then the a/c compressor, the dryer, and probably your evaporator and condenser. One way to do it is to go to Craig's list in your area and find an independent mechanic who will come to your place to do the work and you buy the parts. Unless you have the strength, tools, knowledge you will find yourself creating a nightmare for yourself if you DIY Did the service department tell you exactly what was wrong with your a/c?
If the problem is simply the loss of r-12 freon, add some (it's quite expensive and hard to find because it's no longer manufactured,but not as expensive as a total over-haul of the a/c.). Sometimes a/c shops will tell you that you need to completely modify your a/c for 134a freon. Not true (it is true for the purists though). Just change a couple of Shraeder port valves, evacuate the system, pull a vacuum, then add the necessary a/c ester oil recharge with 134a. It's worked fine for me--no problems. Most U.S. shops won't do this, so you might take a drive across the border where they will gladly do it for you.
 

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For your well-respected mechanic to determine that the repair will be labour-intensive, he/she must know what is wrong! The most labour-intensive replacement will be the evaporator, which is behind the dash. Most other components are under the hood. If diagnosis has been done, see what needs to be replaced. Get a shop to recover any freon that is still in the system. Replace the defective components yourself, then have the a/c shop evacuate and recharge the system. This way you will save some money on parts and labour.
The main components are: compressor, condenser, receiver/dryer, expansion valve, evaporator and the tubes and hoses. You can buy a set of o-rings for about $10, and it will have more than enough for your job.
 

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oh my... A/c can be very complex to troubleshoot and sometimes a simple and cheap to fix solution. Mine was a broken wire rubbing on a bracket.

The On-line manual has how to for everything but it is not easy for the uninitiated to follow. You need to be a bit mechanically and electrically inclined to grasp it.

I would agree the Star knows or at least has an idea what's wrong, but will they tell you is the question.

I can't believe all components would fail but which one. A stupid sensor $ 20 to $ 50 bucks could do it. Just replacing it all would be foolish, IMHO.

I don't know if we can even help. If it is still full of freon maybe we can if we know what it is doing now. For example, if you watch the compressor while the engine is running, does the compressor clutch engage and then shut off after a few seconds?

Has it been converted to 134A yet? There should be a big sticker near the hood latch if is has. Conversion Kit is like $ 20 at Autohausaz.com. They have just about anything you might need as well.

In Calif and if not converted, I think you will have a big problem find the old Freon, it's been gone for years. Some shops horded it for years, smuggled in from Arizona as well, friends bought cases of it just in case. It went to numbers like $ 300/lb in the home refrigerant R11 market Arizona had the DIY cans at the auto parts stores, no clue what AZ is doing now. That being said, I don't think you will find anyone who can pull a vac and put it back in after repairs plus they will need some addition freon as well. Plus I think it's illegal. I had a friend of a friend years ago who would charge my Ford P/u for cheap in his back yard.

I would find a small Import Specialty shop who does A/c, plenty of them around. If not converted, my plan would be to have it switched over. I think that cost me about $ 200 including fixing the leak and freon. They have to notify you before completing repairs so you could then find out what needs to be replaced. Or be up front, and tell em to switch over and have them find out what's wrong but you would replace the parts needed then come back to have them evacuate the system and refill with 134A. Small shops should be willing to work with you, if not try another.

Plan "C". If it has been converted, you can buy a DIY fill can with pressure gauge attached and do your own fill, but the catch is, the system has to be in working order and never been broke into ( can't have opened any lines to atmosphere ) or you need to pull a vac. Kits are mmmm $ 20 or so. Keep in mind, if the system is low on Freon, it will not work at first due to low cutoff relay, so you would have to put some in to find out. If not , you threw away the $ 20. If it does run even for a little bit, then maybe you can troubleshoot it.

Dan
 

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190 aircondition leak

I have a 190e 1993 model 1.8 manual fitted with air conditioning.I have had it converted to 134a and it has worked, but it keeps losing its charge, generally after 2 or 3 days.There is that dye for spotting leaks-green dye,and I cannot spot a leak anywhere. I removed the fascia to see if I could see the evaporator,I found the inlet block in the engine compartment, but evaporator must be in the heater matrix. Any further ideas how to accesses the evaporator?
 

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The evaporator is accessible via the blower motor area. If you remove the cowling and then the blower motor coverings you should see it.
 

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Yep,I found it,but can you believe it, I took car to a local aircon gas guy and while we were gassing it ,we found a green dye leak! It was at the low pressure switch,leaking through the terminal ports! I replaced the unit,recharged, and problem solved.
 
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