300E '92 Refrigerant & Expansion Valve - PeachParts Mercedes-Benz Forum

babymog · #1 09-26-2009, 05:53 PM

Looking at a '92 300E, and the expansion valve says "R134a" on a sticker.

I know that some cars were equipped with R134a in '93, and the '92 was originally filled with R12.

So why the green sticker on the expansion valve? Does this mean that the valve has been replaced, or is this sticker common on the late '92s?

TOPGUN · #2 09-26-2009, 10:56 PM

I removed an expansion valve from a 1989 560SEL. It had an R-134 sticker. The system is R-12. The car was R-12 from the factory. I know for sure it has never been changed. Your replacement valve will be marked R-134. The system operating pressure for R-12 and R-134 are similar. The R-134 valve will work fine. Stay with the R-12. Good Luck.

Rick Hall · #3 09-27-2009, 05:13 AM

Do not worry the expansion valve is good for your car. Stay with R12 for best operation of your system AS DESIGNED. R134 hoses and parts will work in a R12 system. R12 HOSES AND COMPONENTS WILL NOT WORK IN A 134 SYSTEM. I have in my hand an official MB Intro to Service manual that states"Under no circumstances are A/C components intended for use with R12 to be interchanged or used in a systems intended for use with R134" This manual states that R12 Orings are black and will be changed to green in color and can be used for both types. It also states that R12 hoses will have a yellow band on them and 134 hoses will have a green band on them. 134 hoses with special 134 service valves are not to be used with R12 a/c systems. this manual is dated Sept 1991 and tells of the upcoming changes to 134.

280EZRider · #4 09-27-2009, 12:55 PM

Quote:

Originally Posted by Rick Hall

Do not worry the expansion valve is good for your car. Stay with R12 for best operation of your system AS DESIGNED. R134 hoses and parts will work in a R12 system. R12 HOSES AND COMPONENTS WILL NOT WORK IN A 134 SYSTEM. I have in my hand an official MB Intro to Service manual that states"Under no circumstances are A/C components intended for use with R12 to be interchanged or used in a systems intended for use with R134" This manual states that R12 Orings are black and will be changed to green in color and can be used for both types. It also states that R12 hoses will have a yellow band on them and 134 hoses will have a green band on them. 134 hoses with special 134 service valves are not to be used with R12 a/c systems. this manual is dated Sept 1991 and tells of the upcoming changes to 134.

You're right about the O rings. They are all green now. I question the band on the hose though. I recently replaced my condenser/compressor hose - OE with a green band. So I'm inclined to believe that there are no, at least now, yellow banded hoses to be had. Plus, this OE hose with a green band has the R-12 schrader valve, which I don't think can be used with 134 equipment.

Rick Hall · #5 09-27-2009, 02:29 PM

You are correct. I also believe that there are no yellow banded hoses left unless someone has extremely old stock. The manual states that the green banded hoses with R134 fitting can not be used with R12. Keep in mind that this manual was published Sept 1991 and was early info regarding the phase in of R134.

babymog · #6 09-27-2009, 02:34 PM

Thanks for the info.

I was considering using it for a spare, all of my current 124s are '94 and '95 so originally R-134a.

My hope was that this indicated that the evaporator had been replaced and would therefore be a new and viable replacement should I need one, ... but it doesn't sound likely.

Again thanks for the info.