I had the same issue with the 123 when I owned it. Compressor was replaced and the entire system flushed. Two years later, the compressor goes out again and I need to spend another $800. to get it working again.

In many discussions with Larry Bible on this forum, he indicated that this is not uncommon with vehicles converted to R-134. The significantly higher system pressures and the way the compressor is mounted shortens the life of the compressor dramatically.

The solution is to convert back to R-12. If the compressor operates at significantly lower pressures, odds are that it will last significantly longer.

Sure, the R-12 costs more at the initial fill, but, what does a compressor cost you?