2008 Vue XR 3.6L V6 212k miles A/C not working after vacation

[T1gerTr0n]

Greetings,

My family left on a 3 week vacation this June and returned to our parked 2008 Vue. I turned it on while sprucing it up, but noticed that when I turned on the A/C there was a hissing sound behind the dash that I didn't notice before. I tested again and felt for the air temperature to change, but it felt barely cooler than the ambient air and sometimes hotter, like it was trying to turn on but then couldn't. If I turned off the A/C (indicated by the light on the dash turning off) the hissing stopped.
After another check, it sounds like the compressor is trying to do its work, but just warm air blows.
Approximately 9 years ago there was some A/C work done, and then 3 years ago we replaced the compressor. My guess is a hose cracked in the June heat while we were away and broke when I turned it on.
I did however check that there was pressure in the A/C lines, and there was, but I don't have the correct fitting to measure what the pressure is.
Any info on how or where to continue with this fix would be appreciated.

 

[Derf]

Hey sorry for the delay.

You can buy a full gauge set for r134a refrigerant and hook up the high and low side ports to monitor the performance of the compressor and the overall charge. They are not terribly expensive. They also come with a third line that you attach a can of refrigerant to. It then feeds the refrigerant into the low side line when the compressor is running. Make sure that the AC clutch has kicked in and attached to the pulley face of the AC compressor. The clutch should now be spinning with the pulley and turning the compressor. If the total charge gets below a certain value, there is a cut off switch that prevents the compressor from running when the pressure is sufficiently low that it may damage the compressor. When you have a leak, eventually the entire system will empty, and below that certain pressure, the AC clutch will not engage even though the light on the AC button is on.

Do not add r134a mixed with sealant. The sealant gums up the internals, and no shop will work on your system because the sealant ruins their $10,000 AC machines. This is not a joke.

The nicer gauge sets come with screw on fittings to attach to the low and high side valves. The more inexpensive have the valve on the car attaching in the center of a fitting on the end of the hose. Just like air tools and your compressor hose.