Craftsman leaking air only when running

by Nigel Burrows
(Bufallo, NY)

Picture shows leak in Craftsman plumbing

Picture shows leak in Craftsman plumbing

Hello Bill,

Great site. I have a problem with my craftsman 5HP 240v compressor in that it leaks air while the compressor is running.

I've done some research using this site and I think its leaking from the pump to the tank.

I did a soap test and indicated in the picture with a red arrow where it's leaking.

I'm not sure of the model, but on the tank there is a plate with a date of 1985 and MFGS. No 38513138.

Ideally I'd like to get a replacement part, if not will have a go at bending a replacement copper pipe.

Does anyone know the make / model of this compressor?

Any advice?



Comments for Craftsman leaking air only when running

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Aug 27, 2018
Craftsman compressor leak
by: Doug in

If the leak isn't too huge, you might try some pipe tape around the ferrule on the nut side.

Good luck in any case.

Aug 26, 2018
Craftsman leaking
by: Bill

Thanks for the photo. Makes diagnosing the issue easier, for sure, and, thanks for your kind comment.

That's a pressure fitting, and it's allowing air out when the compressor is running only because the air in the tank is locked in by the tank check valve, or, the air would be leaking out here when the compressor is stopped, too.

Did you try to tighten the nut?

There is likely a ferrule inside, and if the tube has become damaged or bent, that ferrule might be allowing the leak.

If tightening the nut doesn't stop it, remove the nut and examine the end. Any damage?

If you can't get it to stop, you will need to change the ferrule and nut, and that means cutting the tube. If there's enough slack you might get away with not replacing the tube.

Yes, to make it easier, you can replace that tube with copper, and you will need a tube bender or it kinks and new end hardware.

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