The mention that 134A conversions fail. The problem with conversions is that while 134a approximates R12 it is less effecient and a system not designed for it has less margin. The other problem is that 134 uses different oils than r12 and needs different seals. So what everyone does is replace all the o rings with nitrile or something that is compatable with the oil forgetting that there are seals in the compressor. Also all the old oil needs to be flushed out and a new receiver dryer installed