Automotive Air Conditioning Information Forum

Has the system ever been worked on for any reason?

With a tiny leak, I think you would eventually notice a slow decline in cooling before anything else.

With a fixed-displacement compressor (presuming that the safety switch is doing its job), you might notice that the compressor cycles more frequently, or stops running altogether, due to the lower ...

The A/C definitely won't work with two OT's. It's worthwhile to check, while you have the system open.

On certain vehicles, GM placed an OT, or just a screen (sometimes mistaken for an OT), at the condenser's outlet. If it has a screen, ensure that it's clean.

Some additional thoughts...

In an earlier topic, I believe the OP mentioned that you changed the OT and that the screen on the original OT was clean. Did you take note of the original OT's color? I believe it should have been black-and-white with a single o-ring and a 0.072" orifice. If so, the new ...

In that case, if you have a garage, preferably heated, pull it in there and check the system for leaks. Pay particular attention to the compressor shaft seal and the condensate coming from the evaporator. If the evaporator is leaking, the condensate usually will contain UV dye if you did add it when ...

I would just replace the lines rather than attempt repairs, which might or might not work.

I don't know. It was 0 when I checked so expected to see something obvious, but saw nothing.
Are you the original owner? If not, then the system has a leak (or leaks), or a previous owner recovered the refrigerant with the intention of finding the leak. Maybe that person didn't find it, or maybe ...

This particular compressor is a clutch-less direct-drive variable-displacement type and doesn't engage and disengage in the traditional sense. It constantly runs whenever the engine is running. It has an electronic control valve that varies the displacement according to system demand.

That said, I ...

That refrigerant is expensive! Did the R-1234yf leak out?

Even in my area, it's only in the high 60's to low 70's during the day.

350μm is very good, but doing MVAC work at only 45°F is difficult. It's hard to test and charge a system at that low of an ambient. Better to wait until the ambient temperatures rise to a minimum of 80°F, or work in a heated environment—easier said than done, I know.

An alternative is to heat the ...