I have an 01 screw 4x4 5.4L which has had the AC sytem drained for about 2 years now all lines are connected. Don't ask how I know its been purged I just do. Never tried to turn on the ac sytems since I knew it was drained. So the other day I was in Napa and noticed these cans of coolant for the vehicles and started to wonder if I could just re-fill the AC system back up with coolant and get it back to working? Or is there other steps I need to do before I tried to refill it. Like change the small filter etc. What do you vatos tink?

 

At the very least, it has to be put on a vacuum pump.