The maintenance of breather valve shall be conducted once a month and twice a month in winter. Its method: first open the valve cover gently, take out the vacuum valve disc and pressure valve disc, and check whether the sealing place of the valve disc and the valve disc, and the guide rod and guide rod sleeve of the valve disc are free of oil and dirt. If there is oil and dirt, clean it up, then install it back in place, pull it up and down a few times, and check whether the opening is flexible and reliable. If everything is normal, cover and tighten the valve cover. During the maintenance, if the valve disc is found to be scratched, worn and other abnormal phenomena, it should be replaced immediately or contact the supplier company to solve them in time.