IR air compressor wont build pressure

by Mark
(Paris, AR)

i have a ir air compressor, 5.5 hp motor, 60 gal tank, it was working fine, i have recently changed the oil in it and it worked ok after that until it starting tripping the reset button.

It will run and build pressure up to about 75-80 psi and will not build anymore pressure than that.

The motor will run constantly and something starts to smell hot and that is when the reset button is tripped; atleast i think so cause when i am around i don't let it run constantly. I do not hear any air escaping from anywhere and have had no problems with the air compressor until now. It is about year old and hasn't been over used. It has a relief valve close to the outlet and it will release air when opened. There is another valve on top of the tank that looks like a relief valve, but when I pull on it, it will not release any air. What do you think?

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Bill says...

If it is a reciprocating compressor, and it won't build air pressure past a certain point, check the inlet to make sure it's pulling air. If so, then it might be an internal gasket issue.

However, if the motor is wearing out, or there is a mechanical issue adding load to the motor, then your motor is overheating from that, and not just from running too long, and it trips out the thermal overload.

From your description, I'd consider the inlet valve first, and the gasket issue second.

Cheers,

Bill