Water contamination is the great enemy to your prized impact wrench and other expensive air tools.
The common misconception is that if you just drain the air supply tank in your air compressor of excess water, you are protecting your air tool from water damage. While draining your air supply tank is good, you are only preventing rust damage in the tank. The air outlet is generally at the top of the tank and the water in the bottom doesn’t make it up there to damage your impact wrench.
How then does water get into your air lines and then to your air tool?
The answer is condensation.
Water condenses and builds up in the air hoses and then travels to your air tool. Also, on a cold winter morning the water that has accumulated in your air lines will freeze and cause even more damage. Frozen water can break loose and damage your tools or even block the air flow in the line.
The solution to this problem is install a water filter in your air hose. A good place to put it is midway down your air hose. There it will be out of the way when use your impact wrench under your car and you are trying to get into a tight space. A small investment in a water filter will go a long to prolong the life of your expensive air tools.