Oil and Refrigerant
We all see a lot of questions about, dyes, leak stoppers, lubricants, inhibitors and snake oil.. all designed to go in the refrigerant circuit and “improve” something.
I just go back to what Ray Johnson always said (Ray is one of my early heroes in the biz and taught me a lot at Carrier classes)
“Oil and refrigerant”
If it isn’t oil and refrigerant, it doesn’t belong in the system.
Now I know there are rare exceptions… Heck, Carrier has a tech bulletin from 2014 dictating that Zerol Ice should be added to certain systems due to TXV sticking issues.
But when in doubt.. Just oil and refrigerant.