If air leaks out the unloader when the pump stops replace the check valve because the check valve leaks air back towards the unloader.
Air compressor valve leaking.
When the air compressor reaches the normal cut out pressure and stops but you notice while the air compressor is off that air is leaking out of a valve attached to or perhaps inside of the air compressor pressure switch.
If air is leaking from the unloader valve when the air compressor is stopped that points to a problem with the compressor tank check valve not seating properly or its failure.
If the air is leaking from the unloader valve then see the page under fixing compressor problems about air continuously leaking from the unloader valve for.
Well if air continuously leaks out of the unloader valve then the compressor tank is emptying and the compressor needs to restart to replenish the air in the tank to get back up to cut out pressure so it can stop on its own.
With the compressor off the unloader valve should not be leaking any air at all after the unloading process a second or two has completed.
I had a look at the check valve and all is good.
Hotdog compressor was working very well till last month when the unloader valve opened while the compressor had kicked in to build up the.
Leaky gasket high pressure inlet valve.
The unloader valve is only leaking when the compressor is running.
Replace the safety valve if it leaks air constantly.
The unloader valve is leaking air when the compressor is running.
The valve on the outside of the pressure switch may look something like the one in the image.
If you find that your compressor pressure switch unloader valve is leaking air continuously then you have located at least one of the leaks on your air compressor.
Air continuously leaks out of the unloader valve on your air compressor and this is a problem.
Replace valve plate assembly.
Safety relief valve not functioning properly.
My little 2 gal.
This video goes over a few main reasons why your air compressor pressure switch or unloader is leaking while the compressor is running or when it shuts off.
Unloader valve is leaking air.
Air leaking from inter stage safety relief valve when compressor is pumping.