Sounds like things are getting better .
You can find a lot of good info on A/C repairs on youtube .
One thing , there is a product called Super-Seal . Or something like that . I have read a LOT of negative things about it . I would not risk putting it in a car or an air conditioning system for a home .
Anytime you hook up hoses to an A/C or refrigeration system , purge the sir out if the hoses and manifold / gauges . Moisture is the enemy of A/C or refrigeration . And air ( containing moisture ) . The refrigeration oil will absorb moisture . The synthetic oil used with the newer refrigerants is worse to absorb moisture than the mineral oil used with R12 & r22 .
Anytime you have a system open to the air , very long , it is important to replace the Accumulator dryer / receiver dryer .
And vacuum down then system to a hard vacuum . This will help remove the moisture , along with the air .
You will normally get the best performance from the system if you charge it with the number of ounces of refrigerant the documentation calls for . More is not better .
God bless
Wyr