Air is coming out of the oil plug during operation

by Whit
(Snellville Ga)

When I use the air compressor after it shuts off I can hear and feel air coming out of the plug for the oil. My oil plug is vented and has to small holes on both sides (from the factory). Is the air compressor bad or not? Also I noticed that the o-ring is also missing on my oil plug. Can I order this part its a standard 3/8" inch threaded plug.

---

Bill says...

Hi Whit. Thanks for writing in.

Your oil plug is vented to allow outside air into the sump so that, as the oil in your sump is used up, air can flow in to replace it so that the sump doesn't pull a vacuum.

I think you've either got a piston ring leak or a damaged gasket somewhere in your compressor. If the unit doesn't unload, then air trapped over the piston may wick past the piston rings into the sump, or as the piston compresses air, the same thing may happen.

Does your compressor deliver enough air? Air coming out the sump is not good, but I wouldn't take the unit in to get it fixed until I was no longer happy with how it supplied compressed air.

Make sure you keep your compressor oil at the right level.

Cheers,

Bill