My apology, and you are correct.  Freeze 12 is 80%R134a and 20% R142b.  It is not a hydrocarbon.  Is this true?  Freeze 12 was developed so that R12 systems could be recharged without changing the lubricant.  The 142b carries the lubricant, but the 134b actually does the cooling.

You find all kinds of stuff, some valid, some not, on the internet.

Of course, mixing the 134a with another refrigerant would not alter the molecular size of the 134a, so if it is leaking because it is smaller than the pore size of the hoses, or from breaches that are too small for R12, so what?

I think I'll take the advice that said try harder to find the leak(s), fix them if found, and recharge the system.  If it is still leaking after another round, I may give up on the AC, and just swelter.  I don't use AC at home much, even when it is brutal, unless someone is sick.

mcneely

---- Robert Fisher <garciasghostvw@gmail.com> wrote:
> Freeze 12 is ~80% R134 and ~20% another refrigerant,  designed to operate
> at pressures closer to R12 system specs. Not a hydrocarbon, and legal if
> the conversion is done properly. It doesn't sound like your choice of
> refrigerant is the issue, tho, unless your hoses are in fact letting it
> pass. So, you're back to finding the leak.

--
David McNeely