I've had my compressor for about 10 or 12 years. It's been used sparingly over that time, mostly for my sandblaster and has always worked well. When I turned it on the other day and it started to fill I suddenly heard air escaping out of it. It seems to start at about 60 psi. If you look at the pics, the air is coming out of the part with the white arrow pointing at it. Not sure what it is as my owner's papers I got with the compressor don't say anything about it. I thought at first it might be the pressure relief valve but the pressure relief valve is behind the on/off switch as shown in the second pic and it isn't bleeding off any air. Your thoughts at what is going on are appreciated.