Thanks again for all the great responses to my WVO question.
Its getting pretty hot here in Mississippi and I'm thinking about spending some tax return money to get the old AC going in my '79 300SD. I heard there was an aftermarket replacement for the servo but can't seem to locate in with the search function. Can anyone help me out here?

 

thanks. thats what I was looking for.
Will installing that make the dash control work again? At the moment only the blower functions when one pushes the top button.

 

I wholeheartedly agree!R134a isbad newsforA/C systems designed around R12. Whatever you do *do not* buy one of those Interdynamics retrofit systems and convert your A/C to R134a. Big mistake.

There are some very good R12 compatible refrigerants that do not require you to retrofit(or even change the existing oil in) your R12 system. A company called EnviroSafe makes a good R12 compatible refrigerantand if memory serves there is another good one called Autofrost. These are not R134a refrigerants and may be used alone or in conjunction with R12 freon.

Unless you are a licensed mechanic it is illegal for you to handle R12 freon, so buying from eBay will put you at risk of breaking the law.

 

Yes. If your system is leak freeand is working properlyyour dash controls should work again once the system is pressurized. There is a pressure cut-off that won't allow the compressor to run when the system is not charged with refrigerant.

 

thanks for the helpful tip. When you say leaks, are you referring to vacumn leaks? Should I just go through and replace all old vacumn hoses and fittings?

 

I'm referring to refrigerant line leaks. You have one, ostensibly, or the refrigerant level would be 100% and the A/C systemwould beworking. You may wish to consult a professional mechanic if you are not sure about what to do. You can cost yourself a lot ofmoney in this area by making mistakes.

Doesn't sound like you shouldbe taking the freon recovery& recycling test for $15 -- put that toward the mechanic's bill and get your car fixed by a good, reliable mechanic who knows M-B.