Air compressor needs help
 

I borrowed my dads air compressor and it worked fine for a week. The other day I started it up as usual got to a full tank and then it starts blowing air out from behind the air pressure switch. Now I have to pull the plug to shut it off without it leaking air from this area. What the hell is going on?

Pressure switch is failed or really dirty. Not too expensive a part, around $20.