Can PAG and mineral coexist in old R12 system?

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Can PAG and mineral coexist in old R12 system?

Postby Swedal » Wed Aug 01, 2018 3:25 am

I'm going to replace a condenser and drier on a Mazda MX6 1993 with R12 system. There is a sticker in german that system contains ozone harmful gas but on the other hand there is a R134 connector on the high side so I really don't know whats in the system and whats done with it. I have tired the system with a HC mix of 50% R290 propane and 50% R600a isobutane (sells as Hychill in austalia) and that works with both PAG and mineral. System cools well but I had to use more R600a because of high head pressure. After replacent of condenser and drier I will use 50/50 mix again and get some better performance.

Now to the question. I will need to add some oil. Can I use PAG46? I know the HC mix will work with both types of oil but what if there still is mineral oil in the system? Customer budget is very limited so I will not mess with a flush and oil change. Will PAG and mineral oil work together with HC?

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