Had the 2nd stage compressor fail on a 2 circuit 4 stage I-pak last fall. I will be changing it out in early spring and have a few questions. In a tandum set up, wouldn't the "junk" from a compressor that went tango uniform end up in the other compressor? So I would think both should be replaced. What say's Trane about it? Also, does Trane ship the hermetics out with full oil charge? Should I dump the old compressor/compressors out of oil and measure amount so not to oil log system.I've replaced my share of compressors both herms. and recips., but never in these units. Thanks in advance for the help. It takes a long time to go through all the red tape to get parts where I work so I'm trying to get all ducks in a row early.