How to use an impact wrench?

Status
Not open for further replies.
Joined
Aug 13, 2002
Messages
917
Location
Singapore
I recently bought a 2hp air compressor and an impact wrench. Im not too sure how to use the impact wrench. Am I supposed to push the impact wrench hard against the lug nut for the impact to work properly? What is the 1-2-3-4 setting for? Dont laugh but I cant seem to get my lug nuts out using the impact wrench.
pat.gif
The compressor is rated at 8 bar & 7.3cfm. The impact wrench says min 80psi & 4cfm.
dunno.gif
 
Is it a cheezy 250 ft/lb Campbell Hausfeld wrench? I have one and it doesn't do much.
rolleyes.gif
 
I have a compressor / 30 gallon receiver tank I have had for a long time. I haven't had success with an impact wrench for lug nuts.

I think it is because I have a pretty long hose on it and have too much pressure drop at the wrench, but I haven't tried to shorten it. Maybe I will as I get older and less fond of using the breaker bar.

Sounds like the numbers are a pressure adjustment, to allow you to dial down to less than full pressure.

It should work when applied normally to the nut, not necessary to press for any clutches or anything. Does it sound like it is impacting -- hammering -- when operated ? Or is it stalled, with just air exhausting ? If it's new, maybe it's broken ?

You should have a special socket for impact use -- thicker, malleable, less likely to fracture.

I may run the nuts on with the impact, but I always tighten to the final value with a torque wrench anyway.
 
Ya the #s are the torque regulator. #4 being the highest setting.

I have that same wrench and it really impresses me. It has absolutly no problem with lug nuts. One squeeze and Wiiiiiiinnngggg! They are off!

I used mine thursday to set up a ring and pinon on a Dana#44 axle w/o any trouble.

I think maybe you don't have enough air pressure, too small hose or have the torque turned down.

How much air pressure do you have?
 
quote:

What is the 1-2-3-4 setting for?

One would assume this is for "torque limiting". Try 1 and then 4 on your lug nuts. If you have a decent FT/LB torque wrench ...determine what the lug nuts are torqued to (the last impact that applied them). This may be beyond the range of your wrench ..with your current air supply.

Most of the more powerful impacts are air hogs compared to your specs. At least that's what my (admittedly old) Snap-On catalog says. Most would outstrip the average compressor's ability to produce the appropriate air psi/volume if run continually.
 
2 hp is not enough to run an impact wrench. 10 cfm at 90psi is a good starting point to make the wrench work. The Ingersol Rand 231 is a great quality wrench for the money .

[ July 04, 2004, 10:41 AM: Message edited by: Steve S ]
 
Yeah it's a brand new 250ft-lb china/taiwan S$60 crappy impact wrench. I brought it to my neighbourhood tire shop and the kind boss tested it for me on his customers car, zzzoooomm, no sweat whatsoever. Then he showed me his store room where he kept his compressor, wow, it looked three times larger than my puny little one. I guess size DOES matter. Then he showed me 4 of his state-of-the-art impact wrenches, the smallest of which cost S$300+ and I really looked & felt like quality all over. I guess maybe my hose is too long (14 meters). I was wondering why my tire inflator tool only registered ~4barg (compressor gauge reads ~7.5barg). I will try shortening my air hose to see if that solves my problem. Here's a pic of my compressor.

[ July 04, 2004, 11:05 AM: Message edited by: Ken4 ]
 
you need one of those old compressors with a belt connecting the motor and pump pulleys.

my friend has one and it's great no matter what cheap tool you attach to it. my dealership uses a substantially larger version of it.
 
The output of the compressor doesn't matter (much). The psi limit and the size of the tank DOES. There are very few compressors (typically) that can run a decent air impact FULL TIME. Have you ever seen anyone run an impact FULL TIME? That's not how you "size" a compressor ..whether it's an air compressor ..or an airconditioning compressor. You do it based on typical demand. If you can run an impact FULL TIME ...you're wasting energy since you will have more "start up" current demand per cfm delivered under typical use (single or two bay setup - not a dealership) You don't use a 150 hp boiler to heat your house. Same with oversizing an airconditioning system (a very common mistake).

You need to "provide" xxx cfm @ xxx psi for the duration of the "use". This doesn't mean that your compressor has to fit your tool...just your reserve capacity. It's not like you're using a jackhammer on a contruction site.

Most of our compressors (not cheap) were all twin piston units set up for 135 psi ..the typical output (for the pulley/motor) was about 8-10 cfm since the typical "duty cycle" of anything we ran off of it was so short.

Shortening the hose will help ..but getting a bigger one will do the same thing. We used garden/heater type hose (off of a big spool) for most of our long distance air pump applications. This allows you to disapate less pressure over the resistance of the hose due to distance.

[ July 04, 2004, 11:53 AM: Message edited by: Gary Allan ]
 
dude no joke i have that exact same compressor only with a larger tank, and i have that exact impact wrench too.

the way i use it is i set the compressors air regulator to 120psi and the impact wrench to full power, i forget if its 1 or 4 thats full power, but anyways i never met a bolt or nut i couldnt get lose with that thing except my 350ftlb cv joint bolts which reuire me to STAND on the breaker bar.....

when you are tightening nuts and bolts set the impact to the lowest setting and reduce the air pressure on the compressor to around 50psi, this is good for quickly putting lugnuts and such on, but still leaves them lose enough to be properly torqued down by a torque wrench later.

i dont think the hose length has anything to do with it. air has little resistance to the small lengths we use, my air hose is 50 foot long and doesnt have any pressure drop.
 
quote:

Another thought is that the air hose inside diameter is important if your using a 50 foot hose. I use a 3/8 and 1/2 inch for runs over 50-100 feet and 1/4 inch for my 20 foot runs.

most impact/air tools require 3/8" hose as a minimum, 1/4" as a short "whip" might be ok but even it will hamper performance.

for your small compressor i recommend turning the regulator up as high as it will go, make sure you have a 3/8" (9mm?) air hose and test each of the setting on your air gun to see which will give the most torque.

offtopic.gif

i own an ingersoll rand "thunder gun" and although it looks and sounds neat when you first get it, the loudness of it get annoying after awhile. it is basically just one of their other comperable guns with no muffler (yes air tools have mufflers) which makes it louder and faster and more "racer" like. it is a fine tool and has a ton of power and speed, but they make others for the same price that are lighter, quieter and just as strong.
 
Any air tool requires a certain volume at a certain pressure. Even a very small compressor and tank can run the biggest tool for a short period if the air can get there. An impact wrench should loosen a lug nut in seconds. With a small compressor, it may be a while until you can do the second one. Diameter of the hose is critical. I am not sure if air works the same, but a 3/8'' hose will supply up to 7.6 times as much water as a 1/4'' one. A hose that is half as long will have half the pressure drop.
 
Set the dial on the gun to 4 wich is the highest setting. Set regulator to 8 bar!!! You have to oil the gun before use. Their should be an oil port pluged with a screw. You also have to add a bit of oil to the air intake nipple side of the gun. Impact sockets are best but standard sockets will work just fine.

You have to push on it only hard enough to keep it from jumping off of the lugnut as it impacts and trys to torque out of your wrist.

P.S. Your compressor is on the anemic side but should be able to get the job done. THat little compressor sounds like a pan cake compressor for running roofing equipment.
 
Thanks guys, I finally got it to work.
biggthumbcoffe.gif
I think Eddie is right, it needs some time for running in. My tire shop friend must have finally woken up the tool from its sleep. When I first got the tool, I used a few squirts of WD40 on the air inlet and it gets really messy and promptly spits it out the exhaust. I tried all 1-2-3-4 settings but no luck. I also pumped some SAE HD90 inside the oiling screw.
rolleyes.gif
Now when I try setting 2, the lugnuts come off real easy.
burnout.gif
 
quote:

Originally posted by Ken4:
When I first got the tool, I used a few squirts of WD40 on the air inlet

WD-40 is bad for air tools in the long run. It leaves a small amount of residue that eventually gums things up.
 
I have used 12gal 5hp and now a 4 gal 3hp compressor and can remove wheel lugs easley IF they were not over torqued. First thing to check is that the air regulator is set for maximum pressure(125 psi?). Next make sure the impact wrench is set for max pressure as some have an adjustment. Impact wrenchs also need run-in time needed to develope max torque. In addition:use some impact wrench tool lub oil which helps seal and protect the vanes. let us know how you make out.
 
Another thought is that the air hose inside diameter is important if your using a 50 foot hose. I use a 3/8 and 1/2 inch for runs over 50-100 feet and 1/4 inch for my 20 foot runs.
 
quote:

Originally posted by XS650:

quote:

Originally posted by Ken4:
When I first got the tool, I used a few squirts of WD40 on the air inlet

WD-40 is bad for air tools in the long run. It leaves a small amount of residue that eventually gums things up.


Exactly. You should be using air tool oil. Any place that sells air tools should carry this.
 
Status
Not open for further replies.
Back
Top