I've read so much different BS on how to charge a liquid (404a) into a system its ridiculous and now I'm starting to get confused. I really wish if people didn't know wtf they were talking about they wouldn't input or give advice on the procedure.

So, I typically input the 404a as a liquid on the high pressure side at the king valve coming out of the receiver WITH the system running. Is this the correct method?

I hear people say leave the system running, shut it off, throttle the 404 in the low pressure vapor side as a liquid, etc.

What is the real procedure and BEST procedure when charging in a liquid state?

And when would you ever want to charge the 404A on the low pressure side if ever?