To check the condition of your reeds and rings run it up to about 100psi and then switch off at the mains not at the pressure switch, then listen at the inlet or take off the air filter and listen for leaking back past the reeds, then pull out the dip stick and feel for crankcase pressure escaping there, if your reeds and rings are ok you shouldn't feel any air escaping leave it like that for an hour or so and then switch off at the pressure switch, if the pressure hasn't dropped in the discharge line it would indicate a good seal at the compressor and the unloading valve should hiss and unload whatever pressure that was in it.
