I am working on a commercial refrigerator. It holds 10 oz of 134a. How much oil do i add to it when i change the spun copper dryer. ( the electric was rubbing it and rubbed a hole in its side. I know this sounds stupid but i mainly focous on residental HVAC but it being winter and all i figured id give it a shot. Its for a major fast food chain id like to continue working for ... any help would be great.