The high-voltage bag of a car is the high-voltage spark plug in the car. Its service life is generally100000 km or even longer, and there is no fixed replacement cycle. Generally, it doesn't need to be replaced as long as it works normally. Common fault types of high-voltage components: short circuit or grounding fault of high-voltage package winding: after short circuit, the low voltage of the battery cannot be converted into high voltage, resulting in insufficient ignition heat, which makes the spark plug polluted by carbon deposit and dirty. Charge and discharge on the surface of high voltage package: the external surface of spark plug is charged and discharged, and flashover occurs due to its surface waste and serious moisture regain. Aging of insulation layer of high-voltage package: after hot car, high temperature or heavy load work often ignites, which leads to rapid temperature rise of high-voltage package and aging phenomenon. When replacing the high-pressure bag, it should be noted that after removing the high-pressure bag, a sticker should be attached to the hole where the high-pressure bag is installed to prevent foreign objects from falling into the cylinder. When installing the high-pressure bag, please use the special torque wrench to tighten the high-pressure bag. If the screw is not tightened, the cylinder may leak air; If it is screwed too tightly, the high-pressure bag may burst.