5F564 compressor it runs then shuts off.
by Steve Conner
Is there something that should unload to allow the 12.5 hp gas engine to keep running after a set pressure is reached instead of cutting the engine off? I just purchased this unit used and nothing seems to be missing but i do not see anything that would be adjustable like an unloading valve or a pressure switch. No manuals were with the unit when i bought it.
Steve, a gas compressor works similarly to one run by an electric motor, except when the cut out pressure is reached.
On an electrically driven air compressor, the motor shuts off when the pressure reaches the cut out level.
On a gas powered air compressor, what is supposed to happen when the cut out pressure is reached, is the throttle is toggled way back, letting the motor slow down to idle. Then, when the cut in pressure is reached, the throttle setting is increased, raising the motor RPM, and generating the power and RPM necessary to compress the air.
In your case it sounds as though the pressure switch is cutting power to the throttle, and it's shutting the engine down.
It may required adjustment, or it may have failed. I am not (never have said I was) really familiar with gas compressors. I think you may need a motor mechanic to look at yours.
Cheers and good luck.
Boxed pressure switch, with regulator and 2 guages.
I don't want a different pressure switch. I like to repair the original one. Can you tell, where to buy a new line-mounted pressure switch for, exactlly same as when I bought it 25 years ago. I refuse to install one of the new ones. Speedair.com does not sell them, nor, Grainger.com. Please let me know if its possible?
If Grainger can't help you, I sure hope one of the visitors to this website can.
Leaking air unloader valve
by Larry Stevens
Air won't stop comming out the unloader valve after the unit shuts off.
Hey Larry, I wish they were all that easy!
Go to the sitemap page, and click the link to CHECK VALVE for details.