If you are one of the guilty folks who slam in a can of AC charge to "top up", this video from FordTechMakuloco goes over how to figure out you went too far and overcharged the system. Enjoy.
Although if you are too low and compressor will not kick in, then you might not get the R134a to flow from the can into the AC system.This is a lot like a oil analysis. If you don't have a baseline to go by then it's just data. If you don't have a known accurate pressure to compare against then you can't just go out and hang a set of gauges on a system and know whether it's overcharged by a lb. of refrigerant or not.
I have tried to use those temperature/humidity charts to compare against pressure gauge readings and that information is also all over the place. It seems to vary by system and moon phase.
Bottom line, evacuate the system and recharge to a precise and accurate quantity and let it go. Anything else is simply guessing. If you have no A/C and it's 95ºF outside then any sane human would drop $10 on a 12 oz. can of R134a and see if they can improve their situation.
I think the above was in the Ford service manual for a Pinto. And shame dumping R12 into atmosphere.In my experience using the old R12 back in the day, no gauges, dirt cheap. This was the way to tell : System obviously low, compressor cycling and blowing 50 degree air from the vents using a stick thermometer. Bypass the compressor to make it run, dump in a 1lb can, right side up. Let it run in the heat 95 degrees, high humidity, at 1200 rpm. Check thermometer. Oh, it got colder by 8 degrees. Dump in another can, oh, almost 33 degrees ! Dump in another can, thermometer went up and high line stopped sweating. OOPSY !!! Overfilled. Disconnect and push schrader valve in to let some out. Keep checkin thermostat till you got to around 33-35 degrees, YAYIt's full. Then throw in a can of compressor oil for the hell of it
....Good ole days
1234yf is outrageous. Makes 134a look like chump changeYes, I use gauges now. R134 is not cheap to just let fly away. R12 was dirt cheap in the early 80's.
Never heard of 1234yf ???? What does that apply to ???
Pretty much everything since 2017 or so.Never heard of 1234yf ???? What does that apply to ???