Check the valve for leaks: When the tire leaks, you should first find out the cause of the leak, and then you can prescribe the right medicine for repair. When checking. First unscrew the dust cap on the valve and drop a drop of water on the valve core. Seal the valve core hole. If the water droplets become blisters and rupture, the valve core leaks and should be replaced with a new valve. If there is no air leakage, use a small bottle filled with water and put it on the valve. If there are continuous bubbles in the vial, it means that the valve core and the valve body are leaking. At this time, tighten the pressure nut and try again. If there are still air bubbles, remove the valve core and carefully check the valve tube for cracks or the cone on the valve core. After inspection, it is considered that there is no problem, indicating that the inner tube is leaking.