The toilet water tank or the toilet water tank drain valve can't keep the water, or the water flow is closed for a while, usually it is caused by dirt around the air hole on the inlet valve cover, just remove it and clean it!

First remove the blue cover, then the pole, the black apron at the end of the pole is used to seal the small hole, the apron inside the small hole is not tightly sealed, resulting in the inlet valve can not be closed!

Finally, take out the inside cover, use a wrench to force the counterclockwise rotation to loosen, remove the cover and clean the rubber inside, then reinstall it!