Hello considering the situation and that you are going to open a compressor with the problem of dirt and then throw thynner and rinse everything and re-weld, did you not think about removing the oil, clean the pipe system well and rinse the compressor without opening it? I only miss it and left them in the sun for a while to warm up and drain as much oil as possible and then pour clean liquid into a few times then the sun again drains and a vacuum only to the compressor to then place . So far they work without problems and of course filter changes. Another gas to use without changing oil is Mp39 and Mp 66 ((which are 401A and 401B)) also one that works very well YH12 and R406 and R409 greetings