Generally, the fuel water separator of trucks has a special drain valve, which can drain water after unscrewing the valve. The operation of the fuel water separator of different models is different. It is recommended that riders read the manual carefully. The fuel water separator is an indispensable device on trucks. The fuel water separator can remove the moisture in the diesel, so that the service life of the fuel injector and the engine can be extended. Many trucks have two small white tanks on the side of the chassis. This tank is the fuel water separator. It is recommended that truck drivers frequently check the status of the fuel water separator, and if the fuel water separator is broken, replace it in time. If the water in the diesel cannot be separated, it will affect the service life of the fuel injector and the service life of the engine. Truck engines are generally high-pressure common rail diesel engines, which require high diesel quality, because high-pressure fuel injectors need to precisely control fuel injection pressure, fuel injection time and fuel injection volume. If there are impurities in the diesel fuel or the water is not filtered clean, it will cause certain damage to the fuel injector. It is recommended that truck drivers choose gas stations with better oil products when refueling, and don't go to gas stations with poor oil products for cheap.