When you have it rebuilt, make sure they use the GM ceramic seal at the front; most rebuilders use the cheap generic carbon seal, and that's the first place they'll leak later on. Also, make sure they "clock" the compressor clutch wiring connector correctly the first time - 99% of the passenger car applications they're used to doing have it on the other side of the compressor.
Rebuilding A/C Compressor
Linear Mode
