PeachParts Mercedes-Benz Forum - View Single Post - W126 A/C System Rebuilt

automch · #2 01-18-2022, 09:19 AM

Be sure to flush the lines and allow them to dry. The main reason R4 compressors fail is lack of lubrication. I learned this trick working in a Ford Dealership in Ft Lauderdale in 1995. Ford was having a lot of compressor failures after changing to the required R134a and sent out this bulletin that said, put 4 ounces of R12 Oil (Mineral Oil) directly into the compressor before installing it and rotate the compressor to distribute it among the internal parts. Then install, evacuate and add required system PAG oil and charge the system. I retired last year after 50 years professional work in the automotive business. I have found this works very well. My 83 300SD has had 3 compressors since new. The one on it now is 11 years old and is quiet and works fine. I have posted this before about the mineral oil and drew a lot of criticism from some who did not like the idea but it works. It seems the R134a will not carry the mineral through the system and it will stay in the R4 compressor. The R134a will still lubricate the rest of the system by carrying the PAG oil as it circulates. As for your original question I do not have a current source but Murry is a valid aftermarket vendor and make quality components. Hope this helps.