Lost a part in my air regulator?

by Paul

I have a Devilbiss F5020 compressor (old Sears product) that had a massive air leak under the gauge console.

When removing the console, the air regulator came apart and I dropped the main spring on the floor. When I reassembled the regulator, and tightened the base nut, there is no out-flow. The knob does not function. I solved the air leak, and killed the compressor.

Apparently there is a part that goes in the knob to put pressure on the spring, but I have no idea what it looks like, or where in my trashed out shop it might be.

When I seat the diaphragm for the regulator on its base, I push down and get out-flow. The knob, however, exerts no pressure on the spring, obviously due to the missing part.

I can't find any exploded diagram of the internal parts to the regulator, so I have no idea what I'm miss, although there appears to be a square receiver in the knob for SOMETHING to seat and push on the spring.

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Aug 03, 2017
Parting Shot (no pun intended)
by: Paul

I'm just posting this to give you a good chuckle, I hope.

Apparently the nut that holds the control button on the control housing looks like a nut for a reason: tighten it with a wrench, not your fingers!

I put a wrench to it, and no more air leak!

But wait, there's more!

As I was reaching for my wrench, guess what I found? The part I searched all over the floor for was sitting on my table saw where I had set the knob down in the beginning. Grrr...

So now I had my missing part, but the knob was epoxied together and can't operate as advertised.

So I removed the washers I'd installed, and replaced them with the original screw/nut assembly. Perfect fit, and the only difference now is that I have to adjust the outflow with the eye-bolt instead of the knob.

Brought the tank up to 120 psi, turned the eye-bold until pressure reached my 90 psi working pressure and so far it's held for 3 hours.

Such is the life of a Montana Redneck.

Aug 03, 2017
Good effort!
by: Bill

You are welcome.

Yes, regulator diaphragms are a wear item and they do eventually fail.

That's why I opt for non-OEM parts when a compressor is off warranty, to try and reduce the fix cost.

Aug 03, 2017
Persevere, adapt, overcome
by: Paul

Well...I cemented the control knob to keep the adjustable part ridged, then threaded a wing bolt into a hole drilled in the top. Put a washer over the spring and the bolt allowed me to compress the spring and diaphragm to adjust the outflow pressure.
At that point, the air leak I was seeking appeared again. The o-ring/gasket between the regulator control and the diaphragm (or the diaphragm itself) is bad.
Bottom line: to correct the original air leak, I needed a rebuild kit (no longer available), or a new air flow regulator anyway. So the lost part is a moot point now.
And yes, I have found a non-OEM regulator in the $20 range. Thank you for your help.

Aug 03, 2017
by: Bill

Paul, I suspect you can find a non-OEM regulator that is virtually the same as the OEM regulator for about $18 or so.

Good luck.

Aug 01, 2017
Good, Bad & Ugly
by: Paul

The Good: You're right Bill, but I did find a Devilbiss OEM 4-port regulator on Amazon!

The Bad: $40, plus shipping.

The Ugly: Telling the Wife I made a $40+ mistake!

Aug 01, 2017
Devilbiss F5020 regulator
by: Bill

I suspect parts for it will not be available.

The good news is a new regulator is. The bad news is the price.

If you google compressor regulators with the old one in hand, I suspect you'll find a non-OEM replacement at a much better price.

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