Got a California Air Compressor at an auction. It had some sort of tire valve which leaked bad and since it went nowhere I capped it. Even before I capped that leak it would fill but when pressure goes down it will not restart to fill. I tried turning on and off plus pried unplugging. Opened the cover and increased the pressure screw and still no luck. I did notice that the fan tried to move and there was a small buss. I am thinking start capacitor. Can anyone give me ideas??

One thing to check is a "check valve" genreally on the top of the tank. One of the symptoms is what you are describing. It's worth a look.

You say it will run but not hold pressure and then will not restart when the pressure is low?

That sounds like the pressure control switch contacts might be sticking. If the motor start capacitor is bad, the motor would probably not run at all.

The pressure switch is pretty easy to replace and most are available online

13 hours ago, Gerald said:

California Air Compressor

That was your first mistake, nothing good comes from that Godforsaken state.

I think Lew has it, the pressure switch is sticking.

Thanks y'all. I was looking for bright brass for the check valve and finally found it. It looked ok, the spring was not jambed together.When I first cranked it up it started fine. It holds pressure but does not kick on at 90psi like it is supposed to , There is a tube from the check valve to the pressure control switch, at the end of it is something like a tire valve and under that a small switch lever. This little deal was leaking air like no tomorrow. I removed that and placed a cap on the tube. Still has the same problem but that fixed a Grizzly many years ago. I can press that switch and contacts spark but does not start up. Found this pressurecontrol switch online in only two places.but cannot get that little valve by itself. So probably gonna cost another 50 to get it up working right.

Hey funny thing the auction people gave me a propane tank and said it was an expansion tank, But it was not set up for that and I have not tested however think it is almost full of propane.

I tried to use this video to repair my switch. I didn't have enough hands to do it but it does explain what the parts do-

Something else I thought of was the unloader valve It takes pressure off of the compressor head so the motor doesn’t have to start against the built up tank/head pressure