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Troubleshooting pneumatic tools

Basic considerations

Please check the following basic conditions before assuming your tool is broken and needs to be disassembled:

A tool should be tested under its specified working load.

Running a tool at free speed is harmful to the tool and will not produce an accurate test.

Make sure the tool is rated for the current application.

Make sure you are using the proper accessories for the tool and its current application.

Common issues

Before disassembling the tool, check these general operating conditions.

Check for restrictions in air flow and pressure

If the tool is running slowly, squirt a generous amount of air tool oil (10 weight) into the air fitting. Run the tool at free speed until it is runnning at the usual RPM. If there is no improvement, make sure there is no debris clogging the screen material.

Check the air pressure at the nearest guage to the tool. Tools in general are rated at 90 PSI, and pulling the trigger on most 1/2" impact wrenches drops the PSI by 20 lbs. The compressor should be set to at least 110 PSI for one tool.

Make sure the CFM output rating on your air compressor exceeds the CFM requirement for your tool. Make sure your hose, couplers, and fittings are correct for your tool. For example, a 1" impact wrench needs 1/2" couplers and air hose to work properly. For more information on setting up your air compressor, go here.

Check for air leaks around the tool's air inlet

Check to see if air is leaking around the air fitting and tool inlet thread. Test by hooking the tool up to the air line, and then drip, spray, or squirt liquid around the area to pinpoint the leak where bubbles occur. Often a bit of pipe tape will fix the issue.

Check the throttle

If the tool starts running as soon as the tool is attached to a live air line, the throttle is broken.

If no air enters the tool when pulling the trigger, something is blocking the air passage. Check the inlet screen for blockage.

Find more troubleshooting help here.

Assembly and disassembly

General comments

Heat the aluminum exterior housing with a small flame torch to allow it to expand for easy assembly and disassembly.

Whenever grasping a tool or part in a vise, always use leather or copper covered vise jaws to protect its surface and prevent distortion. This is particularly true of threaded members and housings.


Do not disassemble an impact wrench unless you have a complete set of new gaskets. Gaskets often rip and/or tear during disassembly.

Disassemble the tool on a clean, neat work space.

Take off one part at a time and lay the parts out in the order they were taken out or will go back in.

Do not disassemble the tool any further than necessary to replace or repair damaged parts.

Do not remove any part which is a press fit or on a subassembly unless the removal of that part is necessary for repair or replacement.


Reassemble the tool in reverse steps of disassembly.

Sometimes the internal components like the air motor or impact mechanism can be assembled together before sliding the outer housing over top.

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