:shake:a unloader releases the air pressure off the head of compressor after it reaches its set max pressure. when you dont have one, its harder to get the compressor to turn when under pressure. it puts stress on that shaft im sure when if first starts up. if you dont hear a hiss after the oasis has pressured the tank to its set psi, then you most likely dont have a unloader. if you stick with it and run it off your motor, then you definitely need one.
Man I am so glad people are using unloaders! They will extend the life of any compressor.