Need some advice on my Air compressor setup

[MRAJB]

So I have a 20 gallon air compress hooked up to a 6ft 3/8" in-feed line, going into a 50ft 3/8 HF hose reel.

I don't have the specs online, but according to the interwebs, the compressor specs:
DeVilbiss Pro 4000
20 Gal
3.5hp
Displacement = 11.9 CFM
8.5 CFM @ 40psi
6.8 CFM @ 90psi
Max Pressure = 125psi
Max RPM = 3450rpm

My impact gun requires 4.7 CFm at 90 PSI. But my gun has very little lug nut removing power. I did find that I was using 1/4 fitting on some of the connector by mistake and has since swapped them to 3/8 fittings.

How can I fix this? I don't think its an issue with the gun, I'm thinking it a hose legth issue. Should I move up to a 1/2 hose? And 1/2 connector all the way to the gun, and then step down to 1/4 at gun air inlet? Any assistance would be appreciated.

 

[vavet]

Do you have a shorter hose you could connect directly to the compressor and still be able to reach your lug nuts? Basically you need to bypass the 3/8 hose to see if you have a hose length/size problem or an impact gun problem.

 

[jsaw]

A lot of people dont realize that 90 PSI means 90PSI at the impact while pulling the trigger. plumb a gage in that you can read at the impact while pulling the trigger.
We had a problem at a shop where I worked, A lot of guys impacts did not seem to have enough power even though static pressure at the compressor was 175 psi.
The maintenance guy made up a t with a gage that could be plugged in at the end of all the air hoses. Sure enough only a few of the hoses would maintain 90 PSI at the end of the hose while pulling the trigger. there were too many restrictions causing pressure loss.

 

[lakelandcat]

You may be running into a problem with volume, 20gl is not a lot of air. Some will say they can bust loose a lug nut with a 3/8" drive gun, but only with a lg volume tank with a lot of pressure. 1/2" drive is a stronger gun but takes more air to run, my guess is thats what you have. If it only busts loose one or two lugs and then gives up thats your problem. Also it takes more pressure to bust loose something like a big truck oppose to a small car.

 

[K'ledgeBldr]

Volume, volume, and more volume.

 

[matt_i]

I'd question the actual pressure switch setting. Are you sure you're getting the full 90+ psi at all? Ime one can hear the difference in the hammer rate if an impact gun is starving for air if the line is too small. It will start fast/quickly and then the metronome slows down.

 

[redmondjp]

Do you have a shorter hose you could connect directly to the compressor and still be able to reach your lug nuts? Basically you need to bypass the 3/8 hose to see if you have a hose length/size problem or an impact gun problem.

For your situation, you need to remove all restrictions in the air path including quick-disconnect fittings and manifold/valve/regulator at the tank. If you tap off the tank with your 3/8" line (maybe a 25' section), with one high-flow quick disconnect at the gun, that will probably produce the best results you can get.

 

[isb cornbinder]

I own and use a SnapOn 5100. It just makes noise on 1/4" hose. The hose cannot supply the volume this gun needs
My system is set to turn on at 120psi and off at 150psi. My compressor is on an 80 gallon tank and the two stage pump is a IR T30. All the shop air lines are black pipe. 1 inch drops and 1 1/2 inch trunk lines.
I bought a 1/2" 50' hose just for the 5100. The performance improved many times over and snapping off a grade 8 bolt takes only a few seconds.
I have used the 5100 to break down truck frames. If a fastener (bolt) will not cooperate in reverse, I am able to overtighten it and snap it off.

https://picclick.com/F-Snap-On-Im5100-1-2-Drive-Air-Impact-Wrench-332464123245.html

 

[BillK]

Off topic sort of but ..... I never use an impact to loosen lug nuts. I break them loose by hand with a 4 way lug wrench or a breaker bar and socket. Impact tools make it very hard to sense a messed up thread and wheel lugs are the most common place to find them.

Just my opinion,

 

[lakelandcat]

Off topic sort of but ..... I never use an impact to loosen lug nuts. I break them loose by hand with a 4 way lug wrench or a breaker bar and socket. Impact tools make it very hard to sense a messed up thread and wheel lugs are the most common place to find them.

Just my opinion,

Especially true with aluminum wheels. Be careful. Use a torque stick.

 

[MRAJB]

OK Thanks, lots of info here. I didn't get an email notifications even though I am subscribed to this thread. I'll try a shorter hose sometime this week. Also look at getting an inline air gauge at the gun, I think it is the length of hose. If it is the length of hose, should I try a 1/2 house instead?

 

[redmondjp]

Half inch hose would help if it's a really long run, but most of the restrictions are going to be at the fittings.

 

[sberry]

Most is at the hose, go around all the stuff with a 25 ft. The gun needs about 20 cfm. You will lose about a pound a foot thru 3/8 hose, maybe a pound or 2 per fitting.

 

[johnyg]

i had a sears pancake unit and could bust car lugs....how good is your gun???

 

[mustang68408]

Sounds like it’s a volume issue... I have a garagmate that I’m plumbing it with 3/4 maxline kit to add some capacity to the system. Also, it’ll scale if i go to a bigger unit in the future.

 

[850xpeps]

I run 3/8 line on my 30 gal compressor. With 1/4” fittings. No issue running my 1/2” NAPA impact to remove lug nuts and lots of power for most I need.

 

[MRAJB]

So I had a chance to try using just the 6ft infeed hose that went from the compress to the hose reel. Using the 3/8 hose, and 3/8 fittings on both ends with my 1/2 impact. Honestly it didn't really seem much better. I did notice that when the gun was in use the PSI on the one tank gauge would drop from 100 to around 80. Is that normal? I'm going to try and take my gun to a buddy's garage. Maybe the gun has given up. I realize that 20 gallon tank is not alot, but I mean I should be able to easily remove one or two lug nuts without issue? I don't care if I need to wait for the compressor to turn on to re-fll the tank, I just need raw nut busting power.

 

[MRAJB]

i had a sears pancake unit and could bust car lugs....how good is your gun???

This is the gun I ahve:

https://www.searsoutlet.com/Craftsm...h/d/product_details.jsp?pid=19025&mode=seeAll

 

[850xpeps]

So I had a chance to try using just the 6ft infeed hose that went from the compress to the hose reel. Using the 3/8 hose, and 3/8 fittings on both ends with my 1/2 impact. Honestly it didn't really seem much better. I did notice that when the gun was in use the PSI on the one tank gauge would drop from 100 to around 80. Is that normal? I'm going to try and take my gun to a buddy's garage. Maybe the gun has given up. I realize that 20 gallon tank is not alot, but I mean I should be able to easily remove one or two lug nuts without issue? I don't care if I need to wait for the compressor to turn on to re-fll the tank, I just need raw nut busting power.

Something must be wrong with the gun if it won’t hammer. You’ve got bigger fittings than I’ve ever used. Our shop only uses 1/4” fittings on the 1/2” gun as well.

 

[MRAJB]

Welp..just to wrap up this thread. I did change all my fittings and quick connects to to 3/8.

I also picked up a cheap HF Earthquake 1/2 impact to rule out my gun. No change in performance.

Anyhow, I found a used 30 gallon Craftsman oiled compressor online rated at 6.0 SCFM at 90 PSI for $200. So far it was able to remove my 140 ft/lb torqued lugs nuts from my car which my old compressor could not do. Time will tell whether the issue is fixed 100%, but I think we are moving in the right direction. Pic of compressor attached.

Thanks for all the help.

 

[EOC_Jason]

For all that cost and effort, you could have just gotten a cordless...

 

[larry_g]

For your situation, you need to remove all restrictions in the air path including quick-disconnect fittings and manifold/valve/regulator at the tank. If you tap off the tank with your 3/8" line (maybe a 25' section), with one high-flow quick disconnect at the gun, that will probably produce the best results you can get.

Lets say this again, a lot of the regulator/ manifolds on these consumer machines are not capable of high flow. Tap into the system so that you have full tank pressure going straight into your hose. 125 psi is not going to kill your rattle gun.

lg
no neat sig line

 

[MRAJB]

Heh..that not a bad idea. Also to the comment about the "go battery powered", I thought about doing that..but I already another air tools. Plus I should be able to get $50-$80 for my old compressor.

 

[joe_padavano]

All I can say is that I regularly use my IR 1/2 impact gun with my tiny Makita nail gun compressor, and I have no problems with lug nuts. I do have to let the compressor pump back up after one or two nuts, but it generates plenty of torque.