There's probably ten zillion posts concerning this topic (that and vacuum leak q's...), but I'm looking for some simple advice on removal and replacement. First off my wife's '80 300TD had functioning AC after spending a grip to convert (don't start please ) and all was were until recently (one year post conversion ) and then est ist kaput. The heater/defroster never worked as well as the Temp wheel, it was an all or nothing proposition. OK fine, she'll live with that she's from GA and likes/needs AC. Funny thing is now it still works if you press the defrost button, granted the cold air comes out the defrost vents (oddly it seems to work better than the normal vents)

So do I pull the dag-nabbed servo and replace it with a George Murphy special (as well as looking over the amp and resoldering/replacing as needed) and if so can a guy with limited space, tools and never having had done this before (I did replace a water pump on a Saab '95 once, so I can work on cars...), or is this best handled by a proper MB shop. Thanks for any insight +/-

Dave

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'72 220D - Needs good home!
'80 300TD - On to 'greener' pastures...
'74 280C (RIP)
Gone Korean, but dreaming German...


"...Heard the diesel drummin', all down the line."

Performance is now selling a digital replacement for the neantherthal Servo. It's pricey, but may be worth the $$. Replacing the servo is a pretty easy job.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

You may have a bad sensor rather than a bad servo - all or nothing temperature problem. You may also have a a bad vacuum element or no vacuum to the system - works only on DEF. DEF is the "default" setting - bypasses all vacuum and other controls to clear the windshield.

If you call George and pay him five bucks, he will send you his troublehooting guide - this will be a great help to you.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

What is a vacuum element? What is the part# ? Is it the same vacuum pump for a central lock?

It's a generic name for the vacuum operated devices that move the flaps in the air system into the proper position. They are equipped with switches that will start the blower and kick the compressor on only when the flaps are right for the function selected. So if there is a failure, or no vacuum to move them, nothing will work except DEF.

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Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Chuck, thank you very much for the info. I give him a call in the morning and go from there.

Dave

__________________
'72 220D - Needs good home!
'80 300TD - On to 'greener' pastures...
'74 280C (RIP)
Gone Korean, but dreaming German...


"...Heard the diesel drummin', all down the line."

I called George earlier this month and he sent me out the guide and his catalog. Of course I've yet to get down to brass tacks, but that's my problem...

Thanks to Chuck and of course George who by all accounts seems to be an gentleman of high regard.

__________________
'72 220D - Needs good home!
'80 300TD - On to 'greener' pastures...
'74 280C (RIP)
Gone Korean, but dreaming German...


"...Heard the diesel drummin', all down the line."