My 95 SC400 has a noisy AC compressor that is best described as a loud hum. Some would think it to be a power stering pump type of noise. I dont think its bearings in the clutch as it goes away when the AC is turned off. Is this going to require a new pump or are there bearings that can be replaced in the compressor without bleeding down the system? BTW, the AC runs great and cools too well.

Mike in Dallas