Thank you for your reply. A couple of months ago, I had a leaking evaporator replaced with a new one by my regular independent Volvo mechanic. He put in a Nartron variable orifice valve, two receivers (he tells me he contaminated the first one) and R12 (several times), as he struggled with AC which would not cool the car much. He gave up and gave me the car back. A few days later the compressor seized and I found black oil oozing out of the receiver. I posted about this, and I was told about compressor "black death" and read about it at www.ackits.com and www.aircondition.com At both websites, prescribed repair consists of replacing every AC component outside the passenger compartment to get rid of metal particles and contaminants that would ruin the new compressor in a short time. Taking apart the AC and flushing each component individually was offered as a least desirable alternative. Since I have no access to an air compressor, flushing tools or the like, I thought I would put in new parts. Old parts are really fouled with black dirt and there are metal particles in the system. I thought about taking the condenser and aluminum lines to be flushed at a local shop, but they turned out to be less than reliable after I took the car there to have R12 taken out. The long aluminum line between the condenser and evaporator turned out to be damaged, whether from rubbing in the car or less than careful removal by me. Since I have to change everything but the new evaporator which I will flush as best I can, I will convert to R134 which I can more easily service myself. I had AC on the 960 serviced at the local PEP Boys and that turned into a nightmare when they nearly blew the passenger airbag and set off the SRS red light on the dasboard, and broke a few things along the way. I had to subscribe to ALLDATA and learn about airbag service, buy equipment from Fluke and special tools from Volvo to set that disaster right. To avoid that sort of thing, I will try to service the Volvos myself until I return stateside. That is why I asked about the possibility of periodically flushing AC and even parts like the condenser, and changing oil and gas, maybe the receiver, orifice valve and even an Airsept screen, to avoid or at least delay compressor failure and the resulting trouble and expense. Best regards.