Impact Wrench Maintenance

[BillyP]

This is a good question for our good friend Bird, resident guru of impact wrenches and other stuff. But everyone else is more than welcome to jump in.

I just picked up a Chicago Pneumatic CP-734 at a junk store for 10 bucks. It seems to work fine. I tried it on some lug nuts on an old truck I had nearby. My question is about maintenance. I shot some tool oil through it but was wondering if there's something else I need to do?

 

[BillyP]

This is a good question for our good friend Bird, resident guru of impact wrenches and other stuff. But everyone else is more than welcome to jump in.

I just picked up a Chicago Pneumatic CP-734 at a junk store for 10 bucks. It seems to work fine. I tried it on some lug nuts on an old truck I had nearby. My question is about maintenance. I shot some tool oil through it but was wondering if there's something else I need to do?

 

[Bird]

Yep, there is something else you need to do. You'll find an "oil" plug on the side of it. You need a hex (Allen) wrench to remove it. Set it down on its top; handle sticking straight up. Remove the oil plug, then roll the tool over until that oil hole is at the 3 o'clock or 9 o'clock position, as viewed from the front or rear end of the tool. If no oil runs out, you may need to add some. Now any oil is better than no oil, but the recommended oil is SAE 20W or 30W non-detergent motor oil (I only used 30W in Texas). In other words, you want the front end of the tool, which is the impact mechanism, half full of motor oil. And that is important. The CP734 is probably Chicago Pneumatic's most popular half-inch impact and they're very good ones. If it's in good shape, you got a real bargain. It should produce 425 ft. lbs. of torque. But if that front end gets dry, there's a cam, cam ball, cam release spring, and two hammer pins in there. Any or all of them, except the cam ball, may break. And of course, as you said, periodically put a few drops of air tool oil in through the air intake.

If an impact wrench is sluggish, a tablespoonful of solvent poured through the air intake, a brief free spin run to blow it out, followed by air tool oil, sometimes perks them right up. Incidentally, a couple of drops of air tool oil is usually sufficient, but you will not hurt the tool by using too much because the surplus will simply be blown out the exhaust. So too much is better than too little.

 

[Bird]

Yep, there is something else you need to do. You'll find an "oil" plug on the side of it. You need a hex (Allen) wrench to remove it. Set it down on its top; handle sticking straight up. Remove the oil plug, then roll the tool over until that oil hole is at the 3 o'clock or 9 o'clock position, as viewed from the front or rear end of the tool. If no oil runs out, you may need to add some. Now any oil is better than no oil, but the recommended oil is SAE 20W or 30W non-detergent motor oil (I only used 30W in Texas). In other words, you want the front end of the tool, which is the impact mechanism, half full of motor oil. And that is important. The CP734 is probably Chicago Pneumatic's most popular half-inch impact and they're very good ones. If it's in good shape, you got a real bargain. It should produce 425 ft. lbs. of torque. But if that front end gets dry, there's a cam, cam ball, cam release spring, and two hammer pins in there. Any or all of them, except the cam ball, may break. And of course, as you said, periodically put a few drops of air tool oil in through the air intake.

If an impact wrench is sluggish, a tablespoonful of solvent poured through the air intake, a brief free spin run to blow it out, followed by air tool oil, sometimes perks them right up. Incidentally, a couple of drops of air tool oil is usually sufficient, but you will not hurt the tool by using too much because the surplus will simply be blown out the exhaust. So too much is better than too little.

 

[BillyP]

I knew you'd know, Bird. Now for the oil plug. I see 2 Allen screws, one on each side.

The one on the left side is at an angle and the body of the wrench has an indentation where this screw goes in. This screw is pointing at an angle, down towards the handle. If the wrench was held upside down, the screw would be upside down

The one on the right side goes straight in.

I sure don't want to take the wrong one out and something fly apart inside /forums/images/graemlins/blush.gif

 

[BillyP]

I knew you'd know, Bird. Now for the oil plug. I see 2 Allen screws, one on each side.

The one on the left side is at an angle and the body of the wrench has an indentation where this screw goes in. This screw is pointing at an angle, down towards the handle. If the wrench was held upside down, the screw would be upside down

The one on the right side goes straight in.

I sure don't want to take the wrong one out and something fly apart inside /forums/images/graemlins/blush.gif

 

[ScottAR]

When you oil the tool, point the tool exhaust away from you for the first air blast...

Learned my lesson the hard way.... Never did get that stain out...
/forums/images/graemlins/blush.gif /forums/images/graemlins/crazy.gif

 

[ScottAR]

When you oil the tool, point the tool exhaust away from you for the first air blast...

Learned my lesson the hard way.... Never did get that stain out...
/forums/images/graemlins/blush.gif /forums/images/graemlins/crazy.gif

 

[Bird]

Billy, the one on the right side going straight in is the oil plug. It should have the word "OIL" stamped in the metal right beside it. It's also bigger than the one on the left side. And yes, if you remove the one on the left side, a small spring and pin are in there. That's what makes the "click" to stop the reverse button when you push it forward and backward. And if you remove it, you can push the reverse button all the way through and out. But at least it's not the kind of spring and pin that will fly out and get lost. /forums/images/graemlins/laugh.gif

Incidentally, I failed to mention before that if the front end is out of oil, it holds approximately 4 ounces.

 

[Bird]

Billy, the one on the right side going straight in is the oil plug. It should have the word "OIL" stamped in the metal right beside it. It's also bigger than the one on the left side. And yes, if you remove the one on the left side, a small spring and pin are in there. That's what makes the "click" to stop the reverse button when you push it forward and backward. And if you remove it, you can push the reverse button all the way through and out. But at least it's not the kind of spring and pin that will fly out and get lost. /forums/images/graemlins/laugh.gif

Incidentally, I failed to mention before that if the front end is out of oil, it holds approximately 4 ounces.