Toyota Repair: a/c freon refill, air bubbles, freon

Question
how to refill the a/c freon on a sienna 2001 le

Answer
The factory recommended way is to remove all the freon from the system and then filling it with the specified amount. You can add freon yourself with one of those kits sold at autoparts and some department stores. The problem is that you don't know how much, if any, freon is in the system,if there is a sight glass you can check for air bubbles in the system with the a/c on, then add freon until the bubbles disappear, some systems don't have the sight glass so there is a chance that you may overfill or underfill the a/c system, if you want to try doing it yourself then get the recharge kit and follow the instructions. If you know that there is no freon in it then add the specified amount, the underhood yellow label will give you that information.