Compressor won't build pressure past 50 PSI.

[samckitt]

If air pressure only builds to 50 psi, & motor runs on & on, then air has to be escaping somewhere. Now that I think about it, I also had to replace the one way valve on the tank where tube from compressor enters tank. Maybe that is bad. Let it run until you get 50 PSI & shut it off & listen for air leak.