air impact wrench question

[Bill D]

I suppose this applies to electric impact wrenches as well. If you are trying to remove a fastener and it is not turning does it damage the wrench internally to leave it run for a while and try to break the bolt free. what about reversing it to try CCW and some impacts to work oil into the threads.
What usually happens to kill a impact gun, do the hammer sand anvil wear down? My brother the auto mechanic told me the cheap tools use way more air and have less torque. I would suppose more leaks at seals do to poor fits.
Bill D.

 

[Mtndew]

does it damage the wrench internally to leave it run for a while and try to break the bolt free.

Most likely yes.
But I guess that depends on your definition of "a while". Myself I wouldn't let it run for more than 5-10 second spurts.
If the impact isn't moving it, you need to resort to another method of loosening it up.

 

[Nmbmxer]

In my experience what ruins an impact gun is failing to oil it every use combined with wet air.

 

[Joe Rogers]

After 30 + years of impact tool experience...IMHO "burping" the tool will loosten fasteners that constant impacting won't. Adding a spurt of fresh air tool oil into the supply port before attacking the tight fastener is also recommended.
Joe

 

[flutedchamber]

I have impact guns over twenty years old that are still good. The only things replaced were some rubber seals and the rings that retain the socket. If the tool is correctly made it will not destroy itself, providing, as Nmbmxer said, it's oiled with each use and fed dry air at the correct pressure. Sometimes it takes 5 or 10 minutes to break a fastener loose. That's what these guns are made for.

 

[duckman]

My Chicago Pneumatic (brand) has over 850 ft. # in reverse usually don't have to run it more than 10 seconds, "DO NOT FORGET THE OIL" this gun has removed bolts that were impossible to remove by normal methods.

 

[Nmbmxer]

After 30 + years of impact tool experience...IMHO "burping" the tool will loosten fasteners that constant impacting won't. Adding a spurt of fresh air tool oil into the supply port before attacking the tight fastener is also recommended.
Joe

Burping works well if you have air lines that are undersized and give you a large pressure drop at full flow. I have a small 5gal tank with a 3/4" hose a few feet long when I need to remove truck lugnuts using a gladhand adapter, can make a small compressor act line a big one for a few moments.

 

[Joe Rogers]

I have impact guns over twenty years old that are still good. The only things replaced were some rubber seals and the rings that retain the socket. If the tool is correctly made it will not destroy itself, providing, as Nmbmxer said, it's oiled with each use and fed dry air at the correct pressure. Sometimes it takes 5 or 10 minutes to break a fastener loose. That's what these guns are made for.

I still have my first IR impact that I bought in 1977. Been rebuilt 1 time with a new anvil. It's older than all the employees in the shop but me and one other old codger. My CP air hammer is older than that by 5 or 6 years.

Joe

 

[flutedchamber]

I still have my first IR impact that I bought in 1977. Been rebuilt 1 time with a new anvil. It's older than all the employees in the shop but me and one other old codger. My CP air hammer is older than that by 5 or 6 years.

Joe

I have an extended shank IR 1/2 inch impact gun that was a gift for buying over $500 worth of Cardo brake products in 1975. My other 1/2 inch impact is a Chicago Pneumatic from 1979 or 1980. My 3/8 and 1/4 inch impact and air wrenches are a mix of IR and CP.

The IR eats socket retaining rings on a basis of about every 5 years, the CP is still repair free except for an o ring replacement on the direction switch. Oil with each use, feed them dry air at the correct pressure and they will last for decades.

This sort of reminds me of my grandsons reaction to my Homelite XL. Yes, it's old, (53 years +-,and the only plastic pieces on it are the choke knob and air filter cover. He believes that chainsaws were invented by Stihl and Husqvarna...and everything else is junk. I asked him what he thought cleared the forests before Stihl and Husqvarna were on the market?

 

[Scottl]

Quality air tools that are properly oiled and fed clean dry air should last decades in professional (daily or close to it) use. I was taught to oil them every time you snap a coupler onto them. In a shop minimum oiling would be first thing in the morning, after morning break, after lunch, and after mid-afternoon break, with additional oiling if you are using it extra heavily. Oil is cheap and excess just blows out the exhaust.

My personal preference is Marvel air tool oil. It lubricates well and displaces moisture that could ruin tools. The suggestion to use it in 5-10 second bursts is right. Extended operation will generate heat that can damage seals. When struggling with a stuck fastener cooling off periods are a good idea. It once took me about 20 minutes to remove a counterweight bolt on an old forklift. I was using the shop's tired old 3/4" impact wrench - about 10 seconds loosen, then about 5 seconds tighten, occasionally pausing to let the wrench cool. During the pauses I would smack the bolt head with a bronze punch and a hammer. When it finally started to rotate I let out a victory yell they probably heard up in the office.

The reason the shop's wrench was so tired was abuse from some of the yahoos who had used it in the past. Not enough oil and lay on the trigger until it was too hot to hold.

 

[Bill D]

I thought for full time use an impact tool needed to have a inline oiler.
Bill D.

 

[PeteM]

I thought for full time use an impact tool needed to have a inline oiler.
Bill D.

Air tools run almost constantly benefit from clean, dry, lubricated air. Decades ago, I had the air system at an auto assembly plant cleaned up (dry filtered air, lubricators, all properly maintained). We got both better torque control and near 2x the life between rebuilds for air tools. But this was a 3 shift operation with 5000 workers, many of them holding air tools of some description.

For most uses (even typical auto mechanics), a couple of drops of oil before a job, with a decent air filter in the line, is adequate. What you don't want is oil in a line you use for painting, blasting, etc.

There are several small in-line oilers you can pair to a heavily used air tool.

 

[David Utidjian]

Yep to oiling before use and clean dry air of adequate pressure.

Sometimes an impact just won't move a bolt if it is really long (cylinder head) and the head is free. I had this problem once on a Jeep with a straight 6 engine. The bolt was seized at the threads in the block and part way up the unthreaded part of the bolt. This was due to the head gasket having rotted away in various places and water getting to those parts. Only solution was a 3/4" drive socket and T-handle wrench with a 3 foot piece of pipe on the T-handle. Had to wind the bolts out... some past 90 degrees before they broke free. Fortunately none of the bolts sheared.

The reason an impact wouldn't work is the bolt is just a long torsion spring... I was just 'bouncing' on the spring with an impact.

-DU-

 

[mjk]

I'll add to the above about oiling before use
If your tool layout allows, prop the tool up so the air connection is pointing down after use.
Any moistue that accumulates during cool down will drain from the open port