My compressor slowly makes 25 psi and no more. It continues to run, but will not build the 100+ psi and shut off. I installed a new reed valve plate and gasket (1 reed valve was visibly damaged) which did not change the problem. The reed valves in the piston top appear to be good and sealing and the piston to cylinder compression ring is not broken. There are no leaks and the check valve to the tank is working. The only thing I can think of is the compression ring is not sealing enough, but I don't know how tight it is supposed to fit.