Pro air2 4hp 30 gal

[Straight Shooter 14]

I have a pro air2 4hp 30gal compressor that just stopped building pressure one day. It wont go above 10psi. It just keeps running and doesnt shut off. Ive tried turning the valve all the way down and back up again but it makes no difference. It runs fine and has never had a lot of use. I cant find any leaks, it just refuses to build pressure. Not sure where to start. The tank valve is no problem or the pressure valve

 

[The Cobbler]

if you're sure there's no leaks,the next place to check is the reed valves and the piston & ring .
I would remove the discharge line from the compressor and run it, put your finger over the outlet & see if it builds pressure against your finger .

 

[Schurkey]

I have a pro air2 4hp 30gal compressor

If this is a 120-volt/15- or 20-amp unit, they're lying about the horsepower.

that just stopped building pressure one day. It wont go above 10psi. It just keeps running and doesnt shut off. Ive tried turning the valve all the way down and back up again but it makes no difference. It runs fine and has never had a lot of use. I cant find any leaks, it just refuses to build pressure. Not sure where to start. The tank valve is no problem or the pressure valve

When my compressor had problems, (built pressure but slowly, and the safety valve hissed all the time) the issue was a broken gasket on one of the valves.


So, as said...look at the valves.

If this is an oil-free compressor design, be prepared for really bad news. Could be piston/ring/cylinder wall problems. The upside is that you can move to a compressor that has actual lubrication, lower RPM, and lower noise.