88 T/C Overheating only with A/C
Reply #36 –
What should the high side pressure be?
Like i said 40* past ambient is about the norm. More than that is something i would not like. Just me.
ROBIN AIR TECH SPECKS FROM THEIR ENGINEERING DEPT
With R12 systems, high side pressure is usually 1.8 to 2.1 times ambient temperature. That means on an 80 degree day, with moderate humidity, we would expect to see between 144 to 168 PSI on the high side. On hot humid days (with R12), you could say ambient temperature plus 100 PSI., and be pretty close.
With R134a it's common to see high side pressure between 2.2 and 2.5 times ambient temperature. On that same 80 degree day we would see between 176 and 200 PSI on the high side of an R134a system. The system operates in a specific range based on outside ambient temperature. Normally around 200 PSIG But not set in stone.
The owner of the car reduced the charge dramatically and lost high side pressures and in turn lost heat. He now does not overheat according to his post at highway speeds. So charging an AC system and knowing how that system works is what we are talking about. That is why a license is required and schooling to understand said system. I am most certain you have a license working in a dealer. It is not going to AUTO ZONE and dumping cans in a system. I was in the parts store this weekend and it was loaded with people buying FREON. Not one can or two they were buying like 4 cans and the counter prson wanted to sell them more. ((( WHAT ))) You know the ones with a low side gauge on the can. Normally one can is more than you need for top off. How can anyone know what a system is doing without high side readings. Anyway it is always great talk shop with you FOE Thanks