Impact Wrench Repair: How to Reduce Friction on Your Impact Wrench

What You'll Need
Impact wrench
Air compressor, hose, fittings
In-line lubricator
Teflon tape or pipe cement
Air motor oil
Petroleum solvent

Impact wrench repair is costly and frustrating when it holds up completion of an important project. The leading causes of air tool failure are moisture and debris. Contamination of the impact mechanism by water causes rust and corrosion. Dirt accumulation obstructs the motion of the hammer. Metal parts become pitted and scratched. This is devastating because obtaining maximum output torque requires smooth surfaces. The best way to ensure that the tool continues to function properly is to follow a regular maintenance schedule. Check the owner's manual or contact the manufacturer if either option is feasible. If not, rely on rules of thumb and industry norms. Lubricate the air motor frequently and grease the hammer mechanism at regular intervals.

Step 1 - Check for Appropriate Air Pressure 

The impact wrench you are using is probably rated for 90 psi. Make sure that you are using the correct air pressure to achieve the maximum torque output. Overtorquing the wrench by exceeding the recommended air pressure increases reduces the life of the impact wrench. Use whip hoses to reduce stress on the air inlets. Seal the junctions with teflon tape or pipe sealant. Choose the correct diameter air hose and couplings for the size of your impact wrench.

Step 2 - Service Air Compressor Regularly

Follow the manufacturer's recommended maintenance schedule for your air compressor to ensure that it doesn't foul the tools it is connected to. Test it for maximum output and drain condensate moisture from the air tank daily to prevent corrosion of the impact wrench's gears or hammer mechanism.

Step 3 - Clear Blockages

If dirt or sludge accumulates in the wrench, disconnect the leader hose and flush the wrench out with petroleum solvent.

Step 4 - Oil Impact Wrench Regularly

It is critical to oil the impact wrench frequently. An inline oiler is the best option for doing this. This is a hose that feeds a constant supply of dripping or aerosolized oil to the gears. Fill the lubricator reservoir with the type of air motor oil specified by the manufacturer's maintenance instructions if they are available. These instructions will also include the required flow of oil in drops per minute. If you do not have an in-line lubricator, you will have to oil the impact mechanism manually. Apply the oil to the tool at least daily. The best time to apply is after using it long enough to warm it up. After adding the oil, run the tool again for approximately 1 minute. This allows the oil to penetrate moving parts.

Step 5 - Grease Hammer Mechanism Regularly

The owner's manual will also recommend a specific type and amount of grease to add to the hammer mechanism at regular intervals. The hammer mechanism should be greased after every 40 to 50 hours of operation. Insert 1/8 to 1/4 oz. of grease through the grease fitting in the back of the tool.