When a new compressor is installed it is filled with appropriate oil through the oil plug in the unit. When the refrigerant is added it mixes with the oil for lubrication. Questions. When a system is evacuated or has leaked empty, is there any oil left in the compressor? If so, how do you know how much oil is needed to recharge? Or does all of the oil/ester mix with the charge? Answers to these questions will help not only myself but also many recent posters. TIA

Many times oil will be left in the compressor. Mercedes has a spec in the TDM that is 40cc of oil for "sudden emptying of system". This is the rule of thumb. Now, when replacing parts, you have to add oil for each part. Each part has a different amount.

By the book, you are supposed to remove the old compressor and drain the amount of oil out of it when replacing and measure it, just to know. Then Mercedes has a process of figuring out how much to put back in. I just go by how much the factory fill is because I have seen so many dry.

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Benzmac:
Donnie Drummonds
1991 GMC Syclone
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM