compressor wont shut off

[brutus]

I have a porter cable compressor model 3551,it builds air fine but won't shut off.No air leaks, Any ideas?

[Dale]

How much pressure are you getting?

It should shut off at about 140 psi.

Is it blowing the safty valve?

[brutus]

The air gauge by the pressure switch goes above 200psi which is normal for this compressor.I replaced the pressure switch and that was not the problem,it still wont shut off.

[Mike]

Hi Brutus. I recently had a customer with the same problem. He tried replacing the pressure switch too but it didn't fix the problem. The faulty part actually ended up being the check valve. It's figure #11 on this diagram:

Porter-Cable C3551 Compressor

I would inspect the valve to see if it's operating properly. If not, here is a link to the valve information page:

Porter-Cable Check Valve #D29280

[brutus]

Thanks I'll check out the check valve ,let you know if that is the problem!

[grockett]

I have a somewhat similar problem, only my compressor ( model C2001-wk ) will only go to 87psi and won't shut off. It does not lose pressure when I shut it off and I have it adjusted to maximum pressure. It gets to about 87psi and stays there no matter how long it runs Any ideas?

[cmoorejack]

Hey grockett,
You may have the piston and sleeve starting to wear out..item #106..part # KK-4964..
available at ereplacementparts.com... this is a typical problem for most of the oil-less air compressors..they just wear out over time from use..you also may have a valve plate assy problem..but once you get into the piston..you will be able to see the wear quite clearly..
hope this helps..
Craig