I recharged my A/C, after being fix from a wreck. I used one of those gauges that comes with the can. I filled it, at idle to the highest pressure in the green, but at 1800 rpms, the gauge will drop to the lowest pressure in the green. But my problem is at a stop light it quits blowing cold, and on really hot days, like we been having, it doesn't seem to be cold enough. Do I need to add more, or is my problem from not having the system vacuumed?
Thanks.