[pkasprzyk]

The main thing to do is to remove all the old oil. The 134a requires synthetic oil. You need to flush the system, replace expansion valve and accumilator. If you don't need a new compressor you need to remove all the old oil from it. You will also need to put new fittings on your high pressure and low pressure side. I bought a kit that came with rebuilt compressor, accumilator, expansion valve, flush and oil for around $250. Evacuate it before recharging. Took me about 5 hrs, but I am a shade tree mechanic. Be sure and replace your old o-rings and be careful with the flush. That is some wicked stuff!