Hi, my system was converted to R-134 by the PO and performance is not good, but it does cool some so I know it basically works. I know the compressor seal is leaking from the green oil dripping out. If I start repairs, I want good performance when I am finished at least. I need to know what to change to convert it back. I am suspicious that the conversion was not correct; for one thing they installed a low-side R-134 fitting on the high side (egad), so I think probably nothing else was changed. Assuming this, can I flush, then install new lube along with a new compressor, then charge with R-12? Advice is appreciated.