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Quincy Air Compressor Leaks Air

Published Categorized as Air Compressor Leaking Air, Quincy No Comments on Quincy Air Compressor Leaks Air

Air leaks can be a significant source of wasted energy on Quincy air compressors. They will cause pressure drops in the system, as well as resulting in additional costs. This article will provide why your Quincy air compressor leaks air, and the most likely locations if you’re looking to diagnose and fix the issue!

Table of Contents

Why Is Air Leaking From My Quincy Air Compressor?

Quincy air compressors leak air for a number of reasons. It could be that the fittings are not sealed, the hose or pipe has a crack, or a compromised component that needs replacing. Here’s a list of the most common components that may be causing your Quincy air compressor to leak:

  • Condensate traps
  • Couplings
  • Cylinder rod packing
  • Disconnects
  • Filters
  • Fittings
  • Flanges
  • Hoses
  • Lubricators
  • Point-of-use devices
  • Pipe joints
  • Pressure regulators
  • Shut-off valves
  • Thread sealants

To help you locate your Quincy air leak, you typically have 3 methods to choose from:

  • Listening and feeling – is the simplest method, but not always the most accurate.
  • Applying soapy water to an area where a leak is suspected – is a reliable but time-consuming method.
  • Using an ultrasonic leak detector – is the best method and has quickly become an industry standard.

For more information on how to find and fix leaks on your air compressor, visit our guide!

Useful Pages on Air Compressor Leaks

FAQs (Frequently Asked Questions)

Why does my Quincy air compressor leak air?

Your Quincy air compressor is leaking air because you may have fittings that are loose and not sealed properly, the air hose or pipe has a hole, or a component is compromised and needs repairing or replacing.

Reader Questions & Responses

Quincy Air Compressor Unloader Valve Leaking – Quincy Air Compressor Troubleshooting


We have a Quincy QR 310 air compressor with our liquid nitrogen plant. Quincy Air compressor unit is supposed to maintain 90 – 130 PSI pressure in the air tank. So when pressure is 130 PSI, the compressor motor stops and when pressure is 90 PSI motor automatically starts. It was working fine for the last three years.

Quincy 310 Air Compressor
Quincy 310 Air Compressor

But now as soon as the compressor motor stops (after achieving a pressure of 130 PSI), air flows out from the top (from the unloader tower) see the attached photo.

I checked for a diaphragm in the unloader assembly, it looks fine no cracks. What can be wrong? It leaks air when the motor is off, no leak when the motor is running.


The Quincy 310 is the pump. Assuming you have this pump attached to a tank, here’s a good place to start, Ram.


Though this page refers to a pressure switch leaking, the cause of that, and the likely reason for your Quincy unloader leaking are, I think, the same. I’m pretty sure it’s a check valve.

Have a look at the page, and add a comment if there’s still a problem.

If you have any questions regarding a Quincy air compressor leaking air, please leave a comment below, with a photo if applicable, so that someone can help you!

By Bill Wade

About Air Compressors has been helping folks with their Air Compressor Problems since 2002 online. We're a community of DIY and Compressed Air professionals who are keen to support everyone across the globe with their air compressor issues and troubleshooting. Whether you're trying to identify an old air compressor, or troubleshoot an error code on a sophisticated new industrial air compressor - the community at About-Air-Compressors.com is here to help you

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