Quincy 325 unloader

[Chuck Fryer]

Hello-
I have an old Quincy 325 that is not releasing pressure, which is kicking the breaker when it restarts. The oil pressure part of the unloader system seems to be working just fine. The local Quincy dealer told me unloader parts are no longer available. So, could it be as simple as replacing the diaphragm? This unit has no check valve between the tank and pump. If it did I would consider using the pressure release on the shut off pressure switch. Any ideas?

Thanks
Chuck

 

[Stillgottimefor1]

Show a picture of the oil pressure valve. There is a screen and felt filter in that. Your setup should look like this?


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[Stillgottimefor1]

Hello-

I have an old Quincy 325 that is not releasing pressure, which is kicking the breaker when it restarts. The oil pressure part of the unloader system seems to be working just fine. The local Quincy dealer told me unloader parts are no longer available. So, could it be as simple as replacing the diaphragm? This unit has no check valve between the tank and pump. If it did I would consider using the pressure release on the shut off pressure switch. Any ideas?



Thanks

Chuck

Hope this helps. Can you physically open that unloader valve or is it stuck?


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[Stillgottimefor1]

When the compressor shuts off and the oil pressure drops you should hear a long hiss as the unloader releases the air in the cylinder. Test until you find out why it doesn’t.


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[Chuck Fryer]

The oil pressure is passing air to the top. It does his air, but not much when it shuts off

 

[Strouty]

This guy has a bunch of videos on the compressor and it may be helpful to spend a bit of time watching. As for parts not being available, I am not sure of that, if they were not available, there would be a superseded part number.

 

[redmondjp]

I'm also skeptical that parts are not available. Worst-case, you could always add a downstream check valve at the tank, and convert to a more common pilot unloader such as most compressors use today. I would only do that as a last resort, but it will work fine.