OK. Just got the 190 back from the AC shop. The word is the R-12 was contaiminated by someone who tried recharging the system with a refridgerant with a sealer which ruined the existing R-12 . The system was flushed and converted to the new 134a. The AC is blowing cold now. Now the bad news. I'm told they found a small leak near the expansion valve, I think that was the part mentioned, and the system has higher than normal operating pressure. I think he told me it was near 300 PSI. I was told that the high pressure could be caused by problems with either the expansion valve or the drier. I have to go back in four weeks for them check with a black light for leaks. I was told they would be able to determine which part was the cause of the high pressure at that time. Can any AC experts tell me if this is making sense or are they giving me the runaround? Thanks in advance.