Air impact not putting out full ft lbs?

[aruba]

Hi,

I was using a brand new air impact yesterday and it doesn't seen to be reversing at its stated 550 ft lbs. It is a brand name unit, attached to 100' of hose to a 4hp compressor with a 20 gallon tank. I have the output pressue of the compressor showing 85 psi.

It would not turn a lug nut off that I could turn off using a pipe and ratchet.

Any ideas?

Thanks.

 

[Blk88GT]

You should be using more than 85psi.....

 

[Zrexxer]

85 psi at the compressor is going to experience some pressure drop in 100 ft of hose. Adjust your regulator to get full working pressure to the impact, then see if it isn't better.

 

[DekeT]

Buy an inline gauge and check your pressure at the gun. Less than ten bucks.

 

[TwoInch]

it is doubtful that if the manufacturer claims 550ftlbs, that you will get the gun to put out that much. they can be over-rated a bit by most manufacturers.

crank the PSI up and see what happens. what size air hose? fittings? try the output at 100psi and see how she does then, and work from there.

 

[Marlin]

I bet if you put a gage at the inlet of the tool after the quick disconnect and measure the pressure while the tool is running, you'll have less than 60 psi. Shorten your hose and make sure it is at least 3/8" I.D. then crank the pressure up to 120 and see how it does.

 

[malibu101]

I agree with giving it some more PSI.

While you have a new unit this should not apply to you but--
I've coaxed a little more out of an impact that's seen some use/wear by oiling it good.
I think it helps seal it a little better, for a few spins anyway.

 

[jeep450]

Haha. What size air hose? I bet it's 1/4". What does the gun manufacture say it needs? I bet it's 90psi AT THE GUN.

 

[jhelrey]

I have my air compressor set up with no regulator. Meaning my impact can see up to 155#s. Works better at that PSI!

 

[shampoop]

More pressure less hose! I got rid of my regulator on my home compressor and it maxes at 120psi and with a 20' hose even at that pressure it's still not as strong as at a real shop. Reading 150ish at the tank is probably the way to go.

 

[Brian_B_]

What they said about the hoses and pressure..but 4hP on a small tank? Gas (I have a 5HP briggs on a 20 gallon tank) or electric?

I know my gas compressor will not put out enough volume to run my cheap impact for more then a few seconds at full power. After that it the power tapers off...the compressor cannot keep up with steady use.

 

[Rico.]

I asked in a thread a long time ago what PSI most chaps here rum their air tools at
and with the exception of paint guns and delicate tools almost everyone ran their tools
at MAX pressure which for most DIY'ers is going to be about 120psi.

I have since cranked up my regulator to run at max pressure for my impact gun,
and I have noticed quite a difference. It even managed to undo a crankshaft pulley
bolt on my sisters car when I did her timing belt last week, and my gun has a similar
rating to yours.

Definitely 85psi through 100' of hose the air will just dribble out the end. If you can
half the amount of hose, make sure it's 3/8" or larger hose too, and then crank up
your regulator to max when using your impact gun you will be spinning off almost everything.

Good luck.

 

[Bullitt427]

I have my air compressor set up with no regulator. Meaning my impact can see up to 155#s. Works better at that PSI!

Same here... 150+ at home and my guns will sometimes see 175 psi on the field truck.

85 psi? My air tools would laugh at that.

Josh

 

[signcrafter]

Larger hose and bigger fittings and higher pressure to start with. Fittings tend to be the weak link since their ID is pretty small unless you buy the hi-flow fittings. If you are running 1/4" or 3/8" hose the fittings are even smaller creating a big restriction of air. So you start with 85 and run that through 100' of hose which will drop the pressure, especially if it's a smaller diameter hose. Then you add in a few fittings to decrease the pressure even more.

You can run 100' hose if you want but size it right so there is less restriction. Huge factories run thousands of feet of piping without problems, but they size it right running 3/4", 1", 1 1/2" and bigger pipe to allow plenty of air through it. Run your compressor at 120 or more if it's capable and get some new hose with bigger ID and you should be fine.

 

[pipsters]

I find I need 120 psi at the tank coming off the regulator to show anywhere near 90 psi at the gun using just 25' of hose.

 

[gsmornot]

I've read here about guys running close to 180 with their impacts because the shop supplies it that way. The gun wears out faster but if you're a home user like me it will still last a lifetime at whatever you can feed it. I just run my regulator wide open unless I'm using one of my nailers.

 

[wreckerman5357]

I run mine at as much pressure as I can get off the wall. The only thing I dial the regulators down for is paint guns, DAs, and my grinder that performs strip disc duty.

 

[Murphy4570]

I run mine at 150psi. Compressor kicks on at 120PSI I think. Damn thing is constantly running. 85psi is weaksauce, run that thing a lot higher!

 

[JASTECH]

I would run 1/2" ID x 100' with HVLP fittings at all ends including compressor. I bought my HVLP fittings from Northern Tool. What Brand, make & model impact you playing with? This will further know what your impact can and should do.

 

[Jason280]

Since we are discussing air hose, what's the minimum diameter hose you would want to use with a 3/4" impact? Can you get by with 3/8", or should you run a dedicated 1/2" hose?

 

[FunkyfullWidth]

You can get by with 3/8 if that's all you have. But 1/2 would be better. And as far as pressure. At home I keep it at about 110 120 psi usually. Pretty much the same at work unless a bolt's ******* me off then I crank it to 150 ha ha.

And for those really stuck bolts, I'll give the gun a quick little spray of wd40 down the hole. Works sometimes.

 

[4x4gearhead]

If you have a real 3/4 in impact with a 3/8 inlet you should be using a 1/2 in hose, you will see quite a difference in performance.

 

[fsdogwood]

You need to measure the pressure at the end of the hose (where the impact is)