I'm new to air compressors. I got a HF 21 gallon oil filled compressor. When I run my impact wrench it runs out of air very quickly. The tank itself does not. I can hear hissing as the regulator refills the 25 ft 3/8 hose.

As an experiment, I hooked a blow gun directly to the compressor. It would work for a split second. My conclusion is that the regulator works by a sensing back pressure. Is there another regulator at reasonable cost that is not such a bottleneck?

I know going with a 3/8 regulator and shorter hose would help, but I was hoping to fix the problem.

Is this it?

Vertical Air Compressor - 2.5 HP, 21 Gallon, 120 Volt, 125 PSI

The important thing about a compressor is its flow rate:
yours is 5.8 CFM @ 40 PSI, 4.7 CFM @ 90 PSI

You'll have to check with the manufacturer of your impact to see if those rates are adequate.

However I suspect you probably already did this since you said the impact runs out before the tank? Perhaps adjust up the regulator? Or you could always replace it. I picked up one from home depot for my other HF compressor that I cracked the regulator on. Works perfectly fine. Was like $15-20

I bought this one not too long ago:

29 gal. 2 HP 150 PSI Cast Iron Vertical Air Compressor

__________________
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Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
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93 190E 3.0 235k
93 300E 195k

Yes it is that compressor. I got the Kobalt 3/8 impact rated at 5.8 cfm. I did turn it up to 120 psi because I read it is supposed to be 90 psi while the tool is being used.

I read in the reviews people are painting cars and running 1/2 impacts with the compressor I got. That's got me thinking they must have done something to speed up the regulator recovery time. With the 3/8 impact I only get about two second bursts before it starts slowing down.

Double post

Hmmm I'm not sure on the regulator. You can certainly replace it. Like I said I bought one from home depot for like $20 to use on my other HF compressor. No complaints for car but all I use it for is to blow off cruise amps.

Here is the impact that I have:
Eastwood 1/2 Inch Twin Hammer Composite Air Impact Wrench

Its the only one I've ever used so I've nothing to really compare it to..but I've never run into a situation where it didn't get the job done...except when I was trying to remove a wheel from my 300D.

I don't blame the impact though. Who ever put the wheel on last was an *******. I ended up BENDING one of those 17mm Heyco wheel wrenches that MB used in the tool kits. The amount of force applied was impressive. The neck on that wrench was hot to the touch!

__________________
Cruise Control not working? Send me PM or email (jamesdean59@gmail.com). I might be able to help out.
Check here for compatibility, diagnostics, and availability!

(4/11/2020: Hi Everyone! I am still taking orders and replying to emails/PMs/etc, I appreciate your patience in these crazy times. Stay safe and healthy!)


82 300SD 145k
89 420SEL 210k
89 560SEL 118k
90 300SE 262k RIP 5/25/2010
90 560SEL 154k
91 300D 2.5 Turbo. 241k
93 190E 3.0 235k
93 300E 195k

To wrap up this thread, I got a 3/8 regulator from HF. Now when I use the blow gun the PSI never runs down until the actual tank is low. The new regulator has a different airflow direction. I had to do some franken plumbing with a street elbow and 4" threaded pipe.

Fixed!

125 PSI Air Flow Regulator with Gauge

It was that one. From the reviews on similar cheap regulators I've read it's best to close the regulator when not in use for longevity. It's actually pretty large. There must be close to $12 in materials in this thing.