@35 PSI but not Sweating

[MorePower7701]

I have a 1990 Ranger, the A/C system is fairly new, all the componates appear to be working correctly, except for a leaking low pressure line. I bought a can of 134a + oil charge to recharge the system, it came with a cheesy presure gauge that states that 35psi is fully charged. I charged the system to 35psi, the suction line is almost sweating and the vent temp is about 52deg with a 91deg outside temp.

I do home HVAC residental and commercial work for a living, it seems that the system is not fully charged, close, but not fully charged. The temp inside the cab was 100+deg so the air going across the evap coil was hot. Would the hot air going across the evap coil cause a the higher suction pressure?

Thanks

 

[skippy]

I have a 1990 Ranger, the A/C system is fairly new, all the componates appear to be working correctly, except for a leaking low pressure line. I bought a can of 134a + oil charge to recharge the system, it came with a cheesy presure gauge that states that 35psi is fully charged. I charged the system to 35psi, the suction line is almost sweating and the vent temp is about 52deg with a 91deg outside temp.

I do home HVAC residental and commercial work for a living, it seems that the system is not fully charged, close, but not fully charged. The temp inside the cab was 100+deg so the air going across the evap coil was hot. Would the hot air going across the evap coil cause a the higher suction pressure?

Thanks

check the superheat,that will give you a clue about the charge.

 

[Sevensecondsuv]

You did convert the R12 system to R134a before putting it in, right? If you only did the $20 swap fitting conversion then expect the R134a to stay in there for about a month tops. The molecules in R134a are much smaller than R12 so the seals on an R12 system can't hold it very well.

 

[MorePower7701]

Thanks for the replys. The system is r134a, fairly new compresser, the evap coil and condenser coil have also been changed before. The suction line is now sweating fine, and the charge seems to be close. I think I might have a presure switch problem, it was not changed with the last A/C service, might be the original. I turned the A/C on this afternoon and the temp kept going down, it held steady at 40deg vent temp, chilly chill. I am still concerned that the low side did not sweat when it was charged, makes me think there are contaminates in the system.