Originally Posted by Bionicycle

You might check if your air compressor has a tank on it, that you have drained the condensation water out of it at a regular interval. I know many times when I have drained the air tank at a company I used to work for, a white foam like stuff came out with the water. I could always tell when it really needed it, because the air wrench I was using would start foaming at the exhaust port. Just a thought.