I am a pretty hard core diyer and my suggestion would be to find a good/reputable a/c shop that you can work with. Ask around and then go and talk to the owner/operator. I found a guy that is not only a good a/c person but also a good all around type of individual. I took the car to him and he told me what all needed replacing. He evacuated the system and I replaced the items that needed replacing and brought it back to him after which time he charged it again (r134 conversion 300D) and viola I have cold air
. On these hot summer days 60-65 dF blowing out of the vents when the outside air is 98 is good enough for me. If it gets too hot I drive the E320.