Q&A

 Master

The required freon is NOT measured by cans but ounces or grams.
What tool do you have? A recovery/recycle machine? A deep vacuum pump? A precision scale? A low-high pressure gauge, perhaps a professional all-in-one machine?
You need these tools to PROPERLY service an A/C system. What about the oil? What kind and how many will you add to the system?
DIY guys creating a good revenue for us after they ruined their A/C system by trying to save some bucks. You can gamble and you may get lucky now, or play a lot more later.
Leave this job for a pro.

Zee