I am now through most of my second season after my epic battle to convert to R134. Starting with a fried compressor, I did a rebuilt Nippondenso from Partshop, new manifold hose, drier, sensors, and Schraeder valve. I had the system professionally evac'd and charged.
System is still working. It has a small leak and I top it up once every six weeks or so. Concur with Steve about the cooling, but it works for me, mainly because the car is in a garage at work. It would be a very different story if it sat out in the sun all day.
I am personally satisfied with the results and glad I did the conversion. I feel like a real AC guy with my little kit from Pep Boys.
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe