Question for John or any of the other consultants

[tbirdtbird]

Greetings, we have a 2019 Corolla in the shop which has a clutch less compressor, and the shaft has sheared.
Not having much experience with this type of compressor, I am seeking comments on such and also wondering if this is a common problem, and if there is a way to prevent it from happening.
Thanks

[Tim]

Give me a minute.

[Tim]

Compressor shop claims. Not a known issue, they have seen. Mainly seals and loss of oil cause some internal stuff, but nothing that hits home as a regular failure.

You're the special one Dave.

[JohnHere]

I've never seen that happen with a clutch-less variable-displacement compressor, either. Normally, the rubber ring should sheer and slip before the mainshaft snaps if the compressor seizes.

Could have been a sudden compressor seizure while the engine was running at higher RPM, or possibly, a metallurgically defective mainshaft.

I believe this car uses R-1234yf refrigerant. I wonder also whether PAG oil intended for use with R-134a was inadvertently added to this system, which takes a special PAG oil used with R-1234yf. Doing so might also cause sudden compressor seizure, resulting in breakage of the mainshaft.

[tbirdtbird]

Thank you.