I helped my neighbor replace the AC compressor in his wife's 93 Astro around April 6th. The previous compressor - which had been in for several years - had the clutch come apart. Within a week of installing the new one (built by Four Seasons), its clutch came apart. We both did not like the way that compressor sounded from the get go, so we got it replaced under warranty with the same Delphi unit that was on it previously.
Here we are a couple of weeks later and the clutch came apart on the Delphi unit (it was running so quiet & the air was getting good and cold). Just to get it back on the road, we replaced the compressor with a bypass pulley. This van has been converted over to R134a. Somewhere along the way, an orifice tube came apart & he thinks it is most likely down in the evaporator (this would have been before it was converted over to R134a - he did flush the system at the time that compressor came apart). His theory is that it is causing a blockage at cruising speed, thereby increasing the high side pressure to the point that it overheats the clutch.
My theory is that something electrical is going on causing the clutch to cycle too much, thereby overheating it. Are either of these theories plausible?? He is going to take everything apart this weekend & flush it all out. We are going to try to back flow the evaporator, to see if any junk comes out of it. I need to add that when both compressors came off, there was absolutely no indication of internal damage. Both compressors were very clean & would still build suction when you put your thumb over the hole & turn the shaft.
We're not sure that they will warranty yet another compressor that had the same problem as the last one. We did replace the accumulator and orifice tube when each compressor was installed. If anyone has any ideas on why these clutches came apart, your input will be greatly appreciated. Thanks in advance.