The hydraulic hammer of CA41-560 in the forging workshop of our factory found that the valve core of the upper air valve was stuck during use, and the temperature of the working cylinder rose to 80 °C, and it was forced to stop. To this end, we have made the following improvements to the upper air valve. The upper air valve assembly is shown in Figure 1. As seen from the AA (improved) view, an air passage is provided that is open to the atmosphere, so the air hammer is in its idle stroke position (the valve is rotated clockwise in the hoist position)