We have an '85 3L Extended cab Ranger. Last year our A/C compressor packed up but I was able to get an identical one from a Mustang. Well, identical physical dimensions. Having replaced it, I lost the complete refrigerant charge, of course. My questions are: 1. What would be the best "over the counter" refrigerant to use? One store sells Red Tek 12a. 2. After losing my complete charge, would I have to consider adding oil to the system now? 3. Do I have to create some vacuum before attempting to fill the system? 4. Lastly, should I do a pressure check to see if it's going to hold gas before buying some and how would I do this. Thanks very much for any help or references to previous threads. What Now?