When it comes to fuel filters, I believe many car owners are unfamiliar with them. Although its popularity is not high, its role cannot be ignored. It can identify the total harmful substances in the engine fuel system, reduce engine wear and blockage. With the aim of popularizing automotive knowledge, in today's article, the pickup truck China editor will introduce the relevant knowledge of fuel filters to you. Car owners have carefully read it.

Working principle of fuel filter
The fuel filter is connected in series to the pipeline between the fuel pump and the throttle valve inlet. The function of a fuel filter is to remove solid impurities such as iron oxide and dust contained in the fuel, preventing blockages in the fuel system (especially the fuel injectors). Reduce mechanical wear, ensure stable engine operation, and improve reliability. The structure of the fuel injector consists of an aluminum shell and a stainless steel bracket, which is equipped with high-efficiency filter paper in a chrysanthemum shape to increase the flow area. The electronic fuel injection filter cannot be used interchangeably with the chemical oil filter.
Due to the fact that electronic fuel injection filters often withstand fuel pressure of 200-300KPA, the pressure resistance strength of the filter is generally required to reach 500KPA or above, while chemical oil filters do not need to reach such high pressure.

Classification of fuel filters
1. Diesel filter
The structure of diesel filters is roughly the same as that of oil filters, with two types: replaceable and rotary. But its working pressure and oil temperature resistance requirements are much lower than those of oil filters, while its filtration efficiency requirements are much higher than those of oil filters. The filter element of diesel filters is mostly made of filter paper, and some also use felt or polymer materials.

Diesel filters can be divided into two types:
(1) Oil water separator
The important function of a diesel water separator is to separate water from diesel fuel. The presence of water poses great harm to the fuel supply system of diesel engines, as rust, wear, jamming, and even deterioration of the combustion process of diesel can occur. National level III and above emission engines require higher requirements for water separation, which requires the use of high-performance filtering media.
(2) Diesel fine filter
The diesel fine filter is used to filter out small particles in diesel, and diesel engines with emissions above Grade III are mainly aimed at improving the filtration efficiency of 3-5 micron particles.

2. Gasoline filter
There are two types of gasoline filters: carburetor type and electronic fuel injection type. For gasoline engines that use carburetors, the gasoline filter is located on the inlet side of the fuel pump with low working pressure and generally uses a nylon shell. For electronic fuel injection engines, the gasoline filter is located on the outlet side of the fuel pump with high working pressure and usually uses a metal shell. The filter element of gasoline filters often uses filter paper, as well as nylon cloth and polymer materials.
Due to the different combustion methods of gasoline engines compared to diesel engines, the overall requirements for gasoline filters are not as strict as diesel filters, so the price is cheap.

3. Natural gas filter
Natural gas filters are widely used in gas fields such as metallurgy, chemical industry, petroleum, papermaking, medicine, food, mining, electricity, urban areas, and households. Gas filters are an indispensable device on medium pipelines, usually installed at the inlet of pressure reducing valves, relief valves, positioning valves, or other equipment to eliminate impurities in the medium, protect the normal use of valves and equipment, and reduce equipment maintenance costs.

How to replace the fuel filter
As the saying goes, if you do it yourself, you will have plenty of food and clothing. Next, the editor will introduce how to replace the fuel filter by yourself, and also provide a more intuitive understanding of the structure of the fuel filter.
1. Disconnect the vehicle's power supply
Remove the vehicle key and disconnect the fuel pump fuse or power from the vehicle to prevent the fuel pump from pumping out gasoline when disassembling the fuel pump.
2. Remove the oil pump assembly
Remove the cushion of the rear seats and the cover plate on the oil pump, and you will now be able to see the oil pump assembly. The oil pump assembly is fixed by a black snap ring. The wire plug and oil pipe on the oil pump can be removed using a special tool. After removing the snap ring, the oil pump assembly can be removed.
3. Replace with a new fuel filter
Remove the old fuel pump assembly and replace it with a new fuel filter. Replace the corresponding components on the old gasoline filter with the new gasoline filter assembly.
4. Apply Vaseline lubrication seal
Install the fuel pump assembly that has been replaced with a new fuel filter back into the fuel tank, and apply Vaseline lubricant to the sealing ring of the fuel pump to avoid fuel or fuel gas leakage caused by the twisted sealing ring.
5. Fixed snap ring
Install the fixed snap ring of the oil pump and use a special tool to pre tighten the snap ring according to the standard torque specified in the maintenance manual. 6. Check for leaks
Install the oil pump cable plug and fuel pipe on the oil pump to test for leaks. If there are no leaks, install the seat. If there are leaks, reinstall the sealing ring.