This is my wifes vehicle and I feel awful that her and the kids have to ride around in this oven. She loves the truck so I am up against the wall trying to fix the air for them. I have replaced the compressor, condenser (now a parallel flow), both evaporators, accumulator, both metering devices. Pulled a vacuum for two hours and vacuum held for several hours after. Pressure tested and it held for several hours at 300 psi. 14 ounces of PAG 46, 68 ounces of 134a and poor vent temps. Something that I cant wrap my mind around is for example, driving this truck a couple days ago (In Phoenix) it was 108F, drove several miles down the freeway and vent temps were mid 60s, definitely better than 108 but not great. Go into our destination, truck parked in the direct sun for a few hours. When we left the ambient temps were still around 100F but now that the sun is going down the vent temps are about 45F. Still hot out but it seems this truck doesnt like the sunlight. It could be 108F outside at night and the AC would be very cold, 108F with sun up and vent temps are mid 60s.
Windows are tinted, plenty of airflow through vents, both evaporator boxes are sealed up with tar tape. I cant get the low side numbers down to a normal level, they are hovering around 48-55 psi while high side is in the correct area of 250 psi. I have even installed a smaller orifice tube than what factory uses and all it does is cause the high side to go up, low side doesnt go down. I do a good share of AC work and have diagnosed a lot of issues on other vehicles but this one has me stumped and I think it is all because the rear system uses a expansion block which is variable orifice size.
I should also note that these numbers are while running both front and rear systems on high with windows down and engine idling ( I didnt have anyone to run the throttle while testing). Anyone else have this issue and find a cure? Thanks fellas and sorry for the long read.
Windows are tinted, plenty of airflow through vents, both evaporator boxes are sealed up with tar tape. I cant get the low side numbers down to a normal level, they are hovering around 48-55 psi while high side is in the correct area of 250 psi. I have even installed a smaller orifice tube than what factory uses and all it does is cause the high side to go up, low side doesnt go down. I do a good share of AC work and have diagnosed a lot of issues on other vehicles but this one has me stumped and I think it is all because the rear system uses a expansion block which is variable orifice size.
I should also note that these numbers are while running both front and rear systems on high with windows down and engine idling ( I didnt have anyone to run the throttle while testing). Anyone else have this issue and find a cure? Thanks fellas and sorry for the long read.