How to Visually Check the A/C Compressor

The compressor is the heart of your vehicle's air conditioner. It sucks in cool refrigerant gas and compresses it to a very high pressure (up to 350 psi), raising the temperature of the gas to more than two and a half times the temperature of the outside air. In this environment, small problems quickly turn into catastrophic failure.  

Perform a simple visual inspection every three months, looking for discoloration on the face of the clutch hub (a sign of heat); oil or dirt around the shaft seal; proper alignment of the clutch pulley and crankshaft drive pulley; and glazing or cracking on the belts.