The method of draining the diesel filter is as follows:
1. Drain water under the diesel oil-water separator, unscrew the small cap under the filter, and close the oil inlet and outlet ports at both ends;
2. The function of the diesel filter is to filter out harmful impurities and moisture in the fuel system, protect the normal operation of the engine, reduce wear, avoid clogging, and increase the life of the engine;
3. The filter element of the diesel filter mostly uses filter paper, and some are made of felt or polymer materials. The filter element of the gasoline filter mostly uses filter paper, and some use nylon cloth or polymer materials;
4. The structure of the diesel filter is roughly the same as that of the oil filter, with replaceable and spin-on types.

Location of fuel filter:
1. One is an external gasoline filter, which is installed in the middle of the gasoline pipeline, and is generally replaced every 20,000 kilometers;
2. One is the built-in gasoline filter, which is installed in the fuel tank of the vehicle and is generally replaced every 100,000 kilometers;
3. This is different according to the design of the car. Now the steam filter of the car is generally located in 3 positions of the car. The first is in the engine room, the second is under the chassis of the car, which is close to the fuel tank, and the third is in the fuel tank, which is connected to the gasoline pump;