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1982 240d 211k miles
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132 Posts
Discussion Starter #1
Hey guys,
I'm the proud new owner of a SWEET 1986 one owner 300sdl with only 97k miles. The car is a dream except the AC does not work. The car sat for most of 7 years only getting driven once or twice a month. Is there a list somewhere that explains the proper way to trouble shoot this? Or is there something that always fails on these? I heard that the evaporator is a beast if that would be the problem. I have a great mechanic but he is not a Benz specialist.
Thank you for your time!
Hip
 

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1990 420SEL, smoke silver/tobacco
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31 Posts
First, see if the comp. clutch is working ( you should hear a click when ac starts). If not, possible stuck pressure switch on dryer. If it does engage, probably low ref. Very low ref. will also prevent the cluch from engaging. Check for loose/broken wires and lines, also. Good luck!
 

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There are tests on the CD service manual that are quite helpful in diagnosing a/c issues.
 

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1987 300SDL
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1,609 Posts
pix please, after all it sounds like the find of a century! :thumbsup:

97k miles, lucky dog..............................................................
 

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1982 240d 211k miles
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132 Posts
Discussion Starter #5
Not sure how to post a picture but I just put a poor picture of it as my avitar.
 

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1982 240d 211k miles
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132 Posts
Discussion Starter #6

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CH4S Admin , Outstanding Contributor
1985 500SEC, 1991 190E 2.6.
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40,096 Posts
Not sure how to post a picture but I just put a poor picture of it as my avitar.
For a how to post pics, scroll all the way down to the help forum, and check the sticky.

Have you tried a forum search? The archive has a wealth of information.

Welcome, to take advantage of all the forum features, please re visit the 'Welcome to the Forum' tutorial sticky on top of the W126 page, as well as the two DIY stickies.
It will show how to search the forum (3 words min.), and has a link to the Russian MB site where you can run a VIN#.
Cheers
 

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1982 240d 211k miles
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132 Posts
Discussion Starter #9 (Edited)
Put the gauges on the AC. There is pressure on the high side and it's pulling a vacuum on the low side. My buddy said there must be a blockage somewhere. Any ideas? I read that there is a expansion valve under the dash. Is this a problem area with these old cars? Sorry for my lack in AC repair knowledge but I do not wanna take it to a Stealer....eeeeerrrrrrrrrr Dealer.
Thanks,
Hip

Gr J,
Thank you for that info :thumbsup: I was able to contact him and order a set of Cd's.
 

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Greek God of the R129
SL500-500SEL-190E
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8,372 Posts
Put the gauges on the AC. There is pressure on the high side and it's pulling a vacuum on the low side. My buddy said there must be a blockage somewhere. Any ideas? I read that there is a expansion valve under the dash. Is this a problem area with these old cars? Sorry for my lack in AC repair knowledge but I do not wanna take it to a Stealer....eeeeerrrrrrrrrr Dealer.
Thanks,
Hip

Gr J,
Thank you for that info :thumbsup: I was able to contact him and order a set of Cd's.
Don/t go to the stealer, you are just low on refrigerant.
Regards.
aam.
 

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1982 240d 211k miles
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132 Posts
Discussion Starter #11
Got a expansion valve, dryer, & 134a conversion kit ordered. Should be in next week.
 

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might be the expansion valve

My mechanic made some mistakes on my '86 300SDL last year: replaced the compressor, then the condenser, then the evaporator, and in the end it was the $26 expansion valve. However, it is not just "under the dash", it is crammed uder the dash! I started to replace it myself, but quickly discovered I couldn't get my hands under there, much less any tools. I have no idea how my mechanic got it done.

At any rate, my '86 died of as-yet-undiagnosed engine troubles: if it turns out you need an evaporator and/or condenser, let me know. I may be willing to part out.

I put at least 600,000 miles on my '86 before it gave up (or I gave up on it). Get the AC fixed and it will darn near last forever.
 

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from small to large
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885 Posts
My mechanic made some mistakes on my '86 300SDL last year: replaced the compressor, then the condenser, then the evaporator, and in the end it was the $26 expansion valve. However, it is not just "under the dash", it is crammed uder the dash! I started to replace it myself, but quickly discovered I couldn't get my hands under there, much less any tools. I have no idea how my mechanic got it done.

At any rate, my '86 died of as-yet-undiagnosed engine troubles: if it turns out you need an evaporator and/or condenser, let me know. I may be willing to part out.

I put at least 600,000 miles on my '86 before it gave up (or I gave up on it). Get the AC fixed and it will darn near last forever.
600,000 miles? That is an encourage for all owners - mine is 170k on the clock, looks like I still have a long way to go - either she wears me out or I wear a little of her :)
 
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