Hello,
I am replacing the ac drier on my 87 300SDL and need to replace the temp switch also. Are the temp switches that are oem replacements R134a compatible? I know the refrigerants operate at different temps so I want to make sure the replacement works.
Thank you
Michael

There is a new formulation available for R12. It is called R12 Super, or something like that. It uses the R12 fittings, compressor, oil, expansion valve, and everything. Same price as the R134a. It is NOT propane. It works better than R134a in systems designed for R12.

My car was converted to 134a. I just had him remove the R12 to R134a adapters, pull a vacuum on the system, check to see if it held, and then add the R12 Super. I does a good job of cooling. He said if it still was not cold enough we could replace the expansion valve and the receiver dryer since they were probably had too much of the 134a oil in them.

It cost me a total of $108, including tax.

-Jim

__________________
1995 S350D, Green with black leather interior.
Bought January 2008 w/ 233,xxx miles.
I did 22,000 miles during the first year of ownership.

And if you do stay with 134a, the stock switch is fine. It will cause the auxiliary fan to come on any time you are stopped or moving slowly, but you'll need it.