The working principle of diesel filter
The diesel oil pumped by the oil transport pump enters the shell through the inlet pipe interface, then penetrates through the filter element and enters the inner cavity of the filter element, and finally outputs to the injection pump through the outlet pipe interface. In this process, the mechanical impurities and dust in the diesel oil are filtered out, and the moisture is deposited in the shell to achieve the effect of filtering the diesel oil. After the normal operation of the diesel engine, the filter can achieve the best effect within 5,000 kilometers of use. With the increase of precipitated moisture and filtered impurities, the filter must be replaced regularly, and the replacement cycle should depend on the quality of the actual diesel used, usually, the use of the diesel filter does not exceed 10,000 kilometers. In order to extend the service life of some diesel filters, a drain plug is designed at the bottom of the filter, and after working for a certain time, the plug can be unscrewed to remove the precipitation water in the filter.

Working principle of gasoline filter
The gasoline pumped by the oil pump enters the housing through the inlet pipe interface, then penetrates through the filter element and enters the inner cavity of the filter element, and finally outputs to the carburetor through the outlet pipe interface. In this process, the mechanical impurities and dust in the gasoline are filtered to achieve the effect of filtering the gasoline. After the normal operation of the gasoline engine, the filter can achieve the best effect within 5,000 kilometers of use. With the increase of filtered impurities, the filter must be replaced regularly, and the replacement cycle should depend on the quality of the actual gasoline used, usually, the use of the gasoline filter does not exceed 10,000 kilometers.

Fuel filter maintenance
After the filter is blocked, the resistance of the filter element increases, and the gasoline flow is not smooth, causing the fuel level in the filter to rise. The internal oil level rise can be observed from the filter housing, so that you can determine whether the filter is blocked.

After the filter element is blocked, the oil supply is insufficient, the engine power is reduced, the vehicle is weak, and the speed is reduced. A car with a speed of more than 100km/h can drop to a speed of 70 ~ 80km/h, or even lower, and the engine acceleration is poor. Cars such as Audi, Santana and Jetta require the gasoline filter to be changed every 15,000km.