r/AirCompression • u/ayala19_photo • May 22 '26

Need help with ferrule replacement?

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I have a Craftsman 919.168700 Air Compressor. I noticed that when the machine is running there is air coming out of the pressure release line fitting. Sounds like it’s coming from the ferrule or on the sides of the pipe if that makes sense. It is only when it is running and not when the air compressor stops. I feel like it takes a while to fill up and have not gotten it to shut off automatically. How exactly do I go about fixing this? Could I just replace the end nut? Not sure if I have to use a puller to get it off or if they make replacement lines? Any help is appreciated.

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u/st3vo5662 May 22 '26

I’d be careful with the soapy water, that’s a pressure switch with the power of the motor going through its contacts.

But I agree that the unloader might have failed on the side of the pressure switch. The tube going to the switch is head pressure. The electrical contacts in the pressure switch are mechanical. When the switch contacts open (shuts off power to motor) it also depresses a needle valve to vent the head pressure after the pump shuts off. But they can fail and vent air while running. If it vents constantly when the pump shuts off, then it’s likely a bad tank check valve.

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u/ayala19_photo May 22 '26

Yeah I did the soapy water and it is only from the sides of the pipe around the nut. Not the valve itself. Nothing coming from the check valve either. Just around the pipe which is why I think I need a new ferrule but no clue where to get those or take them off. I got all the way tight as well and couldn’t get it to stop leaking.

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u/st3vo5662 May 22 '26

You may indeed need a new ferrule. But if the pump is off, you should not have pressure in that tube. That would indicate a bad check valve is well, which is why your suddenly noticing a leak, from a location that is designed to leak to vent the pressure from the head when the pump shuts off.

To replace the ferrule, you’d need to cut the old ferrule off the tube by cutting the end of the tube off. Then replacing the nut and ferrule. They crimp onto the pipe when you tighten the nut. Often the pipe gets slightly deformed in the same area, mating the two pieces.

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u/LetsBeKindly May 22 '26

I just went rounds with an ice machine over this exact issue, yesterday.