My 82 300D Turbo was converted to R134 by the previous owner. I have owned the car for a few months and although the cooling capacity was subpar it functioned. The compressor and the expansion valve are leaking refrigerant oil. I added the UV tracer R134 to check for other leaks and found none. The AC does not cool anymore because enough freon has escaped thereby shutting down the compressor. I purchased a rebuilt AC compressor, new expansion valve and receiver/dryer.

I don't have the equipment to evacuate so I will bring it in to a local Pep Boys, etc to have it evacuated and charged once I instal the new parts. I will instal the receiver/dryer at the last moment so I minimise it's contamination with atmospheric moisture.

My question is should I clean out the system before putting on the new parts? How do I do this? FYI, I have an air compressor. Also what kind of oil should I put into the new components when I instal them. I have no idea about the oil type the last mechanic used when the system was switched to R134 or if he bothered flushing out the R12 oil so I'm concerned about compatability.

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1972 450SL
1982 300D Turbo