Locating the unloader valve on CPF23400S

by Matthew
(Sidney, OH USA)

Porter Cable CPF23400S air compressor

Porter Cable CPF23400S air compressor

Hello Bill,

I've learned a lot from your website and appreciate the support you provide.

As others have experienced, my unit builds pressure but then blows the breaker when it try's to start back up while under pressure. After reading your blogs, I've noticed that I no longer hear the 'hsss' from the head unloading when the compression stops....I suspect the unloader has failed.

My issue is locating it! The user manual suggests that the PRV (valve with the pull ring attached) acts as the tank dump and as the unloader. Do you think/know if this is accurate?

Any direction in locating the unloader is greatly appreciated! Generally speaking, can this device be cleaned or otherwise salvaged, or does it typically just need to be replaced?

Much thanks!
In an effort to reduce cost in compressor assembly, there may be a combination pressure relief valve and unloader valve installed on your air compressor.

One supplier states "Pressure Relief Kit that screws to the side of the ON/OFF Pressure switch. This relief valve is designed to release the built up pressure in the air compressor pump head and lines after the air compressor reaches the maximum pressure allowed by the pressure switch."

I cannot tell from images that I have found on line if your compressor has such.

If you do a search for your model air compressor on line, you will find sources for parts for this combination PRV and unloader.

If no luck, add a comment here.



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