Whats the low side and the high side suppose to be at on our trucks when the compressor kicks in? and when its off?
I think mine has a bit too much because the pipe closest to the firewall gets hot and i don't think my a/c is as cold as it should be

2000 chevy silverado 5.3
Thanks guys

 

The best charge is when the evaporater inlet and outlet are at the same temperature. If the outlet is colder than the inlet it is overcharged, if its warmer its undercharged. Pressures can change depending on ambient temp and humidity.

 

Oops read that back to myself, don't take the above statement as not needing a gauge. I would NEVER charge an a/c system without one. If you have access to Shopkey, alldata, etc they all have the appropriate temp and humidity to pressure charts.

 

Thanks