My father is a home air conditioning man. He helped me out with my a/c on the Jeep. I read that the low pressure should be between 30-35 and I never found a high pressure spec number.
We vacuumed out the system and weighed in the charge with a digital scale. Low pressure is in spec around 32. High pressure is at 250. My father thought the high pressure was a bit too much. He wasn't sure how much high pressure a car system is supposed to have. If the high pressure is out of spec whats causing it?
The system was blowing warm air when the jeep got hot. Like above 210. Seems to be ok now after we vac and charged the system. Only issue is the temp. of the air coming out the vents. Its blowing 66 degrees max a/c fan on full. Its 85 degrees outside. We checked my dads f-150 and his was blowing 40 degrees! What temp. should be coming out the vents?

 

you can try Following this chart. it normally works for me.
For vehicles currently running with freon R-134a only
Outside-----low side-------High side------Center vent temp
60 F -----28-38 psi----130-190 psi ----44-46 F
70 F ------30-40 psi ---190-220 psi ----44-48 F
80 F ------30-40 psi ---190-220 psi ----43-48 F
90 F ------35-40 psi ---190-225 psi ----44-50 F
100 F -----40-50 psi ---200-250 psi ----52-60 F
110 F -----50-60 psi ---250-300 psi ----68-74 F
120 F -----55-65 psi ---320-350 psi ----70-75 F

 

The pressure is fine. Make sure you run the rpm to between 1500-2000 RPM to make sure it doesn't rise about around 275

 

High pressure is still a little high for the air temp. But my vent temp. is way off. It was 85 out and my vent temp was 66 degrees. Chart says there should have been 45 degree air coming out. My dad said to clean the evaporator coil but its in the dash. I do need to replace the heater core. I would replace both while i was in there. Everyone seems to think pulling that dash apart is a real fun job.

 

With only 66 supply air temp you have a problem somewhere. Clean the Evap coil. Also did your dad weigh the proper charge in?

 

He weighed in the charge with a digital scale. Can the evaporator coil be cleaned without removing? I see only one write up on it.

 

Not sure, but I dont think it can. I pulled my HVAC box out and cleaned it. Get a can of Evap coil cleaner, the foam kind. Works well.