DevilBiss Pro 4000 - air leaks out until it kicks on at 95 psi

by Arlan Vierra
(Hilo, HI)

I have an old DevilBliss Pro 4000 3.5hp with a 30 gallon tank.


Parts don't seem to be around for it. It needed a new pressure switch and a shroud. Can't find a shroud for it. I will probably fabricate one out of sheet metal.

I put a pressure switch on it and the switch has a by-pass. It must not have a check valve since the air leaks out until it kicks on at 95 psi.

Do you have any ideas on this? I don't know if there is a check valve in the manifold and its stuck or if it should have a switch without the by-pass.
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Adam:

1) Why do you need the shroud? If you don't need it, don't put it on.

2) Don't quite know about the pressure switch bypass, I suspect that it's for the unloader valve.

3) Usually the tank check valve is where the line from the pump enters the tank. It does sound like your check valve is leaking. Is there not one there?

Cheers,

Bill

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Nov 06, 2013
Engineer
by: Ray Stubbs

I have the same air compressor, and the check valve is leaking air. Where can I get parts for this compressor?
Devilbiss is saying parts are no longer available.
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Using parts from a decent plumbing store, you can sometimes build a replacement using a one-way (check valve), elbows and tees. As long as the check valve can be threaded into the tank port, and the air gets over to the unloader, you're good to go.

B.

Jun 08, 2012
Model #
by: Arlan Vierra

The model number is RA350E30AD. I found some parts for it. A check valve, piston and sleeve. It has a manifold that must have a check valve that is broken. I'm having a hard time loosening the manifold from the tank and was wondering if you have any suggestions on how to get it out.

May 27, 2012
Reply
by: Arlan

I think the shroud would direct the cooling air over the compressor head. There doesn't seem to be a check valve in the manifold. Probably didn't have an unloader valve originally. The switch I had gotten did. Just ordered one that doesn't have an unloader. I could send you a picture of he compressor, so you would have a better idea of what it is.

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devilbiss prfb5020vp - does it stack up?

How does this compressor stack up against other similar units?

Thanks,
Jim
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Hi Jim. That's a difficult question to answer, given the broad range of comparably sized compressors out there, and the general nature of your post.

Stack up how? Compressed air production? Price? Expected life? Warranty? What's available where you are? Too many variables, Jim.

See how to select from the nav bar for pages providing tips on all the questions you'll want to answer for yourself.

And, if someone out there has this air compressor and wants to offer Jim some advice, please chime in.

Cheers,

Bill

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What is value of 2001 Devilbliss pro air 2 80gal 650 hp air compressor

hello, I have 2 of these air compressors and I'm trying to sell them. my business has failed and I'm trying to sell my shop tools. any help about the value would be appreciated. they are in excellent condition. thank you, Albert
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Hi Albert...

Look on line and see what others are selling for. Check the industrial journals on line too.

Essentially they are worth what people are prepared to pay.

I have added your post and others may contribute. It would have been better for you, I think, if you had added some contact info in here along with your location as anyone interested would need that info.

Bill

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Aug 28, 2013
any good
by: darrin

thinking of buying a devilbiss air compresure I cant make out full model # looks like ral6660v pro 4000 6.5 hp 60 gal I have never herd of them are thay any good and about what did this thing cost new help

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Devilbiss Model 445 Leaking Air Back through Compressor

by Marcus
(Calgary, Alberta, Canada)

Model 445 15 HP .

Compressor is leaking back through the compressor head. You can here the leak, and the pop-off pressure valve will trip on the bottom of the cylinder. Its not bad yet just started. Any help would be great.
Thank you
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This is the twin cylinder model, and as such, should have a PRV in the line, or plumbed to the line, between the cylinders.

If it is the PRV popping off between cylinders, or at the second cylinder, then I would suspect that the valve(s) on the second cylinder air not working properly, impeding flow, and causing an overpressure in the line, popping off the PRV.

If you can feel or hear air bleeding back out of the air intake, then the valve(s) there are failing. Air should only be pulled in, not allowed back out at the intake.

Maybe it's time for a replacement valve job for both cylinders, and if you do, make sure you replace any seals and gaskets at the same time to elminate another tear down in the not too distant future.

Bill

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Oct 31, 2013
Model 445 Leaking Air Back
by: Marcus

Hi Bill,
thank you for your quick reply regarding my question, I was heading down that road and I think with your confirmation I will purchase a valve kit and forge ahead in terms of the work.
Thank you again and I will post my results for your site.
Cheers, Marcus
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Good luck, Marcus. I look forward to hearing about the results of your rebuild.

If you have the time and inclination, take some photos of the process, add a little information that you think might help folks, and contact me through the contact page. I'll be happy to put up a page showing folks what you did, and give you accreditation.

Cheers,

Bill

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