Air Compresser Expert Needed

jvincent57

I have a SENCO PC1005 compressor with a Condor MDR 21-EA/11 pressure switch. When the tank reaches full pressure (120psi) and the switch cuts out the small in line valve that comes out of the bottom of the switch (check valve ?, pilot valve ?) bleeds off pressure until the tank is about 90psi. This is below the cut in pressure so the pump tries to start but the head pressure is too high so it trips its breaker. My guess is I need to replace the small valve , but I have not been able to properly identify it. It's about 1/2" dia, 2" long, is held into the switch body with a set screw and has a quick push in fitting for the vinyl tube on the other end.
Am I on the right track ? and if so
Where can I get the part ?

Mr Chips

here's a good place to start
http://www.senco.com/Documents/Guides/PC1005_PC.pdf

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iamrfixit

The small valve located on your pressure switch is an unloader valve, it bleeds the pressure off of the compressor head and discharge line. This is done so the compressor does not have to try to start under load, it sounds like it is working fine. If it is bleeding down the pressure from the tank as you describe, your problem is very likely the check valve. The check valve is located where the discharge line from the compressor enters the tank. It may look like just a fitting, but it is actually a one way valve that will let air into the tank but not back out.

jvincent57

I cleaned and lubricated the check valve and it's working much better.

Thanks for your help !!!