Compressor won't build pressure past 50 PSI.

[GregWeld]

I really have no idea where to go from here... it doesn't make sense that the compressor would "run on" - yet only make 50 psi - if the regulator was bad. To me that would allow the compressor to run on and NOT shut off... or wouldn't let it start.... but if the compressor is making "only" 50 psi - and continues to run without building pressure.... something else must be going on. What that is - I have no idea.