This is on my 60 gallon CH compressor. The intake plastic was warped and was doing little or no filtering, so I added on one of those round filters with the paper element. It has a small pipe for the intake (and leaks around circumference of the metal cover, but I figure its still filtering through the element, so no big deal). I noticed that at the inlet pipe there is outward air pressure when the compressor is running. My question is should the reed valves be working so efficiently that there is no outward pressure at the intake? the compressor doesn't take an extraordinarily long time to fill and it does reach its pressure, but I don't want to unduly stress the motor or the piston. I just don't know what is normal.