This is a very good thread with some excellent comments. I particularly agree with Larry Bible regarding learning a/c systematically. Although it's not rocket science, it can be complicated and expensive if not done correctly. However, a system built or rebuilt correctly can last for many years. I have worked on quite a few of them over the years and have two complete rebuilds that are going on 20 years with original freon. Never a leak or problem. (Actually, I am always surprised when I start them up after winter and they work!) But, I have been careful, and was taught by a master at a/c work, my father, and we have all the tools necessary.

DS
87 300D
01 Dakota