Air Leaks Out
       Of Compressor?

Question: My air compressor is leaking air pressure.?

When I start my compressor and it builds the pressure fine, but by the end of the day it has leaked out. Please advise. Thank you, Barry

Response:

Well Barry, you run up your air compressor to cut out pressure, you use some air, the compressor kicks on, it fills the tank and stops, and then you do not use any more air, leaving the compressor tank full?

It is a good idea to leave the compressor tank empty and with the tank drain open to allow tank water to void. Having said that, if you want to leave air in the compressor tank, it is entirely up to you.

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Resources:

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So, it seems from your question that your air compressor has a leak somewhere. Finding it is the challenge.

Air compressor line fittings do leak from time to time, but the first thing I would do with your air compressor is let the compressor fill to cut off, and then feel around the unloader valve to be sure air is not bleeding out there. If it is, that suggests that your tank check valve is not seating fully or properly, and you will need to clean or replace your tank check valve to stop this as the source of the leak. If you are not sure what the unloader valve is, see that page linked from the sitemap page for details.

If air is not bleeding out of the unloader valve, then unplug your air line from the compressor discharge coupler after the compressor tank has filled. This will isolate the compressor from the air hose and air tools which, in themselves, might be the source of an air leak. Monitor the tank gauge to see if the pressure drop continues. If so, now you know the leak is at the compressor for sure. Soap all the fittings on the compressor discharge plumbing from the tank to see if any of them leak. If so, gently tighten the offending fitting with a wrench.

If you do not find a leak in the discharge plumbing, and it is not the tank check valve leaking air out the unloader valve, then double check your tank drain valve to make sure it is shut tight. Or, as I have already recommended, when you are finished with the air compressor open that tank drain fully to blow out all the water. Now you have no air in the tank to leak!

Cheers, Bill