my tire stem has a tiny air leakage. I left the car there for repair . then I was told the nut on tire stem got rounded up and ask me to find a mechanic. The guy showed me how he loosen the nut by rachetting it clockwise. I told him you should do it counterclockwise. He said I know what I am doing. Oh, well, did not fix the air leakage issue and have a round up nut need to fix out of my pocket. ~Wenlei