On Mon, 26 Apr 2004, Mike Collum wrote:

> I've also read that the hoses should be changed to the "Barrier" type
> because the originals are too porous.  I didn't change mine and they haven't
> leaked yet, either.

The story I've heard is if the R-12 hoses have been in service long
enough, they may have developed a coating of oil inside that will act like
a barrier.  Since the R-12 oil doesn't mix with R-134a, that coating will
pretty much stay where it is.