bring a small bottle with some car shampoo mixed with water and let water drip on the lines and if it makes bubbles there is a leak. as flash said as well check for leaking fluid, check color of fluid if it has a sight glass. open the drain valve on bottom of compressor after it builds up some pressure and see if theres a ton of water or not, if there's a lot of water you know the tank is pretty rusty on the inside... but generally thats not a big issue if the compressor is not all that old.....make sure it starts and stops on its own when the power switch is in auto mode. other then that should be good machine for what your trying to do with it, just don't expect it to run many air tools...
