AC Troubleshooting Assistance

Did not see a discussion for AC, so posting here (mods feel free to move).

Acquired a 2014 5.7 with 200,000km 8 months ago. It had code b1423 (low pressure). There was no pressure in the system. I charged it, the compressor clutch would not kick in. Bad compressor (clutch was seized).

I replaced the compressor, Condenser, Expansion valve, all o-rings, Idler pully, tensioner, belt. Vacuumed the system and charged it up. It worked wonderfully for 3 months, ice cold air.

Now it's blowing hot air. Compressor is engaging. Taking a reading with guages:

AC OFF: Low 36psi High 30psi
AC ON: Low 0psi High 50psi

No OBDII codes. My reader also shows no faults for the Toyota AC system.

AC experts - what would the next troubleshooting steps be? Is this indicative of a leak? Thanks so much!

If it helps, my reader has the ability to check AC switch status (which is fine), Air inlet damper targ pulse, evap fin thermistor, air outlet servo pulse, air mix servo targ pulse, ambient temperature.

 

What’s the ambient temperature there? Those pressures are pretty low, you may have a leak somewhere. Refrigerant with us dye and a black light. Otherwise I’d say AC specialty shop. When replaced compressor did you clean system of contaminants? When you pulled a vacuum did it hold? And how long did you wait to see if it held?

 

Thanks for the response!

20c (68f)

I bought the dye before charging, but I read that it can also harm the system so I did not add any... regretting that decision now. Might recharge with the dye as a next step. I also have a cheap refrigerant detector/sniffer off Amazon I picked up.

I did not. Because I was replacing all of the components other than the dryer, researched seemed to say that was not a requirement.

Yep, pulled vacuum for 1hr. It held for 4+ hours, not a single PSI of loss.

 

Well with the compressor on it looks like it’s pumping though pressures are low, I wouldn’t worry about the dye, I use it regularly on commercial systems, never had an issue just use the type compatible w POE oil, just pull out what’s left of the old refrigerant and weigh in a new charge and run it for a bit and check for a leak