Craftsman Pneumatic Impact Wrench, Rebuild or Replace

[39Tudor]

I purchased my Sears branded Chicago Pneumatic Impact Wrench back in 1982. It was the first air powered tool that I purchased after buying a small air compressor. Model 756.18882.

Last weekend , I went to use the impact to rotate the tires on my truck. When I hooked it up to air, it will spin with no load but if you put it on a wheel lug, it just sits and bypasses air.

Yesterday I contacted my local Chicago Pneumatic Service Center and asked if they can service this old Craftsman model impact. The tech quickly responded that the Craftsman version is equivalent to a CP734H and there are still parts available to rebuild my impact.

The tech said it will cost $50 for overhaul labor plus cost of any parts. A quick search shows a rebuild kit runs about $40. So I will probably have about $100 to refurbish my 30 year old impact wrench.

The tech also included a link to a new CP734H on Amazon for $115.11. The tech recommended spending the extra $15 and replacing the impact with a new one.

So my dilemma is do I spend $100 to rebuild my old wrench or just spend $15 more and get a brand new wrench?

What Would The Garage Journal Experts Do?

I would appreciate your thoughts, comments, and guidance.

Thanks,

 

[parks31]

I would probably buy a new one at that price point. With the new one it will be in your hands in a few days. It may take a while for the old one to be rebuilt and you might need it sooner at nearly 40 years old you got your monies worth!

 

[The Cobbler]

I'm the kind of guy that likes to figure out why stuff doesn't work & repair it, even if it's not really economical.
but, why not tear into it, see if you can figure out what the problem is (maybe the vanes) and go from there. you can always buy a new one if you screw it up .
I don't think I would spend $100 taking it in when a new one can be had for $115.
I probably would spend $50 on parts if I was fairly confident I could do the repair myself.

 

[Professional Tool User]

You could take it apart and see if there is something wrong with it like a o ring or something cheap and easy to replace and then order the part if you really want to.

However, I would just use this as an excuse to move on to something else. I was handed down a made in Japan Craftsman gun that worked fine, but once I started to run into seized bolts, I knew it was time to move on. The non-variable trigger was also annoying. My shop foreman told me to check with the Snap on guy if he had any used rebuilt MG725 guns available. I couldn't be happier after spending the $250 and upgrading. If the claimed power levels on the Harbor Freight Earthquake and Earthquake XT guns are not exaggerated, if you are a DIYer that's what I would think about getting next.

 

[Wrench97]

After 30 years replace it.
Rebuilds are never the same as new.

 

[jacked_72]

I'd get the new one. Sell the old one as "needs rebuilt" for $20 and you ahead of the game. Or try to get a bunch of ATF into the veins through the input and see if something frees up.

 

[Cheapskate]

You could take it apart and see if there is something wrong with it like a o ring or something cheap and easy to replace and then order the part if you really want to.

However, I would just use this as an excuse to move on to something else. I was handed down a made in Japan Craftsman gun that worked fine, but once I started to run into seized bolts, I knew it was time to move on. The non-variable trigger was also annoying. My shop foreman told me to check with the Snap on guy if he had any used rebuilt MG725 guns available. I couldn't be happier after spending the $250 and upgrading. If the claimed power levels on the Harbor Freight Earthquake and Earthquake XT guns are accurate, if you are a DIYer that's what I would think about getting next.

I agree about taking it apart to see what exactly is wrong before doing anything. It could just need bearings and/or vanes(not sure if those are sold separately, I assume they are). You might be able to get it working again for $10. Here's a video showing exactly how to rebuild that impact:

<iframe width="560" height="315" src="https://www.youtube.com/embed/KTdKYtqO94I" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

And as stated, the numbers on that impact aren't very impressive. It's only rated at 310 ft‑lbs. For the same money you could get something from Harbor Freight that's theoretically more powerful, smaller, lighter and cheaper.

https://www.harborfreight.com/12-in-ultra-compact-xtreme-torque-stubby-air-impact-wrench-63534.html

I have the regular Earthquake and it seems plenty powerful for anything I've ever needed it for(which honestly isn't much) but easily takes off my trucks lug nuts on the middle power setting while feathering the trigger.

 

[bwringer]

Drop $100 on a HF Earthquake and enjoy a whole new world of torque. You'll break **** you never thought you could break.

If you get really bored or sentimental, take that tired old gun apart and you'll learn a thing or three. But even at its best, it's just weaksauce compared to the newer stuff.

 

[NUTTSGT]

Both, maybe. Buy the rebuild kit and a new one. Why not have two ?

 

[Fedwrench]

Let it go, how often did you use your old impact?

The 734 series was the original workhorse for Chicago Pneumatic the same way the 231 was the workhorse for IR.

Impact wrenches have evolved so much over the years why not spring for an IR 2135 or something else lighter and more powerful than a 40 year old impact design?

Now's the time to take the leap

 

[Reese]

Those guns are easy to repair. The only issue is if the motor plates are worn or the hammer mechanism is worn, it wont' be worth the effort.

That video was painful to watch.

To disassemble you remove the rear cover screws and hold the gun over a pan and pop the anvil with a rubber mallet to knock everything out of the case.

To reassemble you stack the motor on the rear cover, squirt some air tool oil in the motor, re-assemble the hammer and fill it with 30 weight oil, stack the hammer on the motor, heat the housing with a propane torch slightly, slide the housing on, and install the rear screws.

We used to hone the cylinder with a brake hone and polish the end faces of the rotor by chucking it in a drill press and using sandpaper wrapped around a file.

 

[TailGunner3000]

Personally, I'd tear into it to see if there's an easy fix. But after nearly 40 years, it owes you nothing.

You, on the other hand, owe it a place of honor hanging in your shop or over the mantle next to Grandpappy's old springfield. After all, old tools never die. They become wall art!

 

[vssjim]

I have all parts in stock to rebuild a CP 734, the H model is the new version with exhaust out the bottom of handle vs front exhaust like you have. I like 734's and use them at work everyday but here is the deal. If it just needs a tune up kit that is air motor with rotor blades and gaskets and seals fine but if a repair kit is needed with impact hard parts that have anvil and hammer pins your 40,00 kit may not be enough as cam ball pilots and Hammer cams and other parts not in kit wear also. I like them and have some that have cast in the motor plate stating it was made in USA or CP New York, New York so that's why I keep them running. I use to rebuild air tools for customers in another time so I have done a lot. Cost wise you are better off with a newer wrench but I have many impacts and for killer tight stuff I get them out but a 734 or an IR 231 are great tools in their day but still fit the bill for me so I keep them going.It's really up to you as what your needs are if you are only going to have one these days probably need a stronger tool but just need to see what you do and go from there.

 

[39Tudor]

Thank you all for your responses.

I am going to take it apart and see if there is anything that jumps out at me.
Like I posted in my original post, when I apply air to the impact, it will spin when the trigger is pulled. It will not hammer, it just bypasses air out the exhaust ports.

As a DYI hobbiest, I may use my impact once every 6 months or so. I use it to knock all the lug nuts loose when rotating tires and knocking mower blade spindle bolts loose maybe twice a year.

I found 2 rebuild kits available, one rebuilds the air motor and the other adds the parts for the hammer and anvil end.

Thank you again for your comments and recommendations.

 

[bwringer]

Take some pics while you're in there!

 

[ImportTuner]

I would replace it ... a impact wrench that is that old did the have the torque the new ones have. It still would be fun to take it apart though.

 

[Farmall450]

Drop $100 on a HF Earthquake and enjoy a whole new world of torque. You'll break **** you never thought you could break.

If you get really bored or sentimental, take that tired old gun apart and you'll learn a thing or three. But even at its best, it's just weaksauce compared to the newer stuff.

This, sadly. Those old girls don't put out what my 1/4" Hex Cordless DeWalt Driver does.

 

[emeraldcoupe]

9 times out of 10 it's going to be a broken hammer pin. easy to replace and cheap.

 

[vssjim]

As a side note to disassembling the unit leave in the small bolts in the back cover just loosen them but take out the larger bolts and push tool down on the anvil and motor and parts should push out. When they are tight I warm the case with a propane torch and also reassemble I warm case first as everything slides much better . I always oil case and motor when reassembling. To reinstall the parts I set in on the back cover and stack parts up and slide case over them fill impact mechanism with engine oil before putting in case. Leave the small motor bolts loose until larger case bolts are tight and move cover around until it fits good on the case as it is adjustable to fit back of tool then tighten motor bolts.

 

[39Tudor]

Thank you for the rebuild tips.
It may take me a week or so to get into this but I’ll take pictures as I go so you can see the process and progress.

 

[Schurkey]

https://powertoolrepairohio.com/pages.php?pageid=14&breakid=222

Buy only what you need. That wrench, in good, used condition is worth about $20--$30 plus whatever sentimental value it may have. There's heaps of them in pawnshops.

As said by many others, forty years ago that impact wrench was the "standard of the industry". NOW it's a gutless turd compared to newer designs. A quality modern 3/8 impact wrench will have almost the same power and use less air.

The "new" 734 is pure Chinesium. You won't get thirty years out of it. Well, maybe, if you use it every six months.

You're on the right track: pull it apart for cleaning, lube, and inspection. Yes, you'll probably find a broken piece in the impact mechanism. When it was my similar-design Mac impact, it was the round item the ball bearing spins on. The "bowling pins" are another common failure point. (Items 93, 94, 99)

If you can fix it cheap enough...fine IF you aren't finding fasteners that the tool wouldn't remove when it was working. IF (big IF) you've already had issues with it being under-powered AND you have at least 90 psi AT THE TOOL WITH THE TOOL RUNNING (not 90+ psi in the air tank) it's time to make some wall art, and buy a real impact wrench.

I suggest any of the "third generation" Snap-On impacts, the IM5100, 6100, or 6500HD. Used, inexpensive, important parts still available because the "guts" are similar to what Snappy is using in the current line of impacts. A "fourth generation" TX7100 or MG725 will be newer and marginally more powerful. Any of these (working properly and fed appropriate air pressure) will completely kick *** on what you have now.

I have an MG725 as my primary 1/2" impact, but I bought an IM6100 as a "beater" secondary unit to reduce wear 'n' tear on the 725. The 725 now only comes out when the 6100 won't turn the nut.

Don't like Snap-On? There's plenty of used, QUALITY impact wrenches to choose from. I nearly bought a Mac AW434 which, I think, is a re-branded IR244. IR and CP and Aircat and plenty of others will have "new" impacts with similar or greater power, but they'll be Chinesium.

 

[Speed-Racer]

If you love that impact, you can buy another one on eBay any day of the week and the cost of a ‘new’ gun maybe cheaper the the parts with shipping.

I would suggest you search for another model on eBay Like snap-on or classic IR USA made. With the cordless electric impacts being popular, an air gun can be picked up for a bargain price on eBay or other stores. After all can you never really have too many impacts.


https://www.ebay.com/itm/Sears-Craf...464446&hash=item3407dbe05d:g:PuwAAOSwYHxWIqTO

Expired auction

https://www.ebay.com/itm/Vintage-Ch...=true&nordt=true&rt=nc&_trksid=p2047675.l2557