Hello Creekers,
I have a 5 h.p. /60 gal. Craftsman air compressor in my shop. Recently it seems to run and run and run to build up air pressure in the receiver tank. To quantify that, I timed it...it took 17 minutes to climb from 60 psi tank pressure to 90 psi, then another 22 minutes from 90 psi to almost 120 psi, at which time I manually shut it off. That was with the tank valve closed (no parasitic losses in my piping layout). My initial thought was the pressure switch, but noodling it a bit more, I'm wondering if there are piston rings that are the problem in the compressor? Never had one of these apart. Any thoughts or ideas? Thanks in advance.