【Mrefilter】Diesel fine filter drain and deflate

Diesel fine filter is usually opened and closed under the diesel oil-water separator to drain water.

1. Diesel fine filter is a diesel fine filter designed for the current two-stage filtration commonly used in diesel engines. It forms a two-stage filter together with the diesel oil-water separator. The oil-water separator is used to filter the water in the diesel, and the diesel fine filter is the fine particles in the diesel;
2. Models that use high-pressure common rail engines under the National Three Standards have higher requirements for diesel quality. Because high-pressure fuel injectors need to accurately control fuel injection pressure, fuel injection time and fuel injection volume, they require more refined workmanship. If there is water or impurities in the diesel fuel that are not filtered cleanly, it will cause wear and tear on the plunger and even parts of the fuel injector until the fuel injector is stuck. Damage to the fuel injector will cause unstable or weak acceleration of the engine, or malfunctions such as black smoke emission, which will affect the normal operation of the vehicle;
3. As the main filter in the two-stage filtration, the diesel fine filter is also the last line of defense against impurities. It has high requirements for filtration efficiency and service life. At present, for diesel heavy trucks of the National Three Standards, the filtration efficiency of 35 micron particles is required to be as high as 98.6%, the filtration efficiency of particles above 510 microns is 99.8%, and the filtration efficiency of particles above 10 microns is required to be 99.9%. While ensuring high filtration efficiency, small flow resistance must also be met to ensure the reliable operation of the engine and sufficient power.

How to deflate the diesel fine filter:
1. Because air has great compressibility and elasticity, when there is a leak point in the oil pipe between the fuel tank and the diesel engine oil pump section, the air will infiltrate when air leakage occurs. Thereby reducing the vacuum in this section of the pipeline, the suction of the fuel in the fuel tank is weakened, and even the flow is cut off, causing the engine to fail to start;
2. In the case of less mixed air, the oil flow can still be maintained and sent from the fuel delivery pump to the fuel injection pump, but the engine will be difficult to start or the engine will stop after a short time after starting;
3. When the amount of air mixed in the oil circuit is a little too much, it will cause several cylinders to cut off the fuel or the fuel injection amount will be significantly reduced, and the diesel engine cannot be started. At this time, the air in the oil circuit must be drained.
4. Secondly, we need to check for leaks in the pipeline. The fuel supply system of a diesel engine is divided into a low-pressure oil circuit and a high-pressure oil circuit.

The replacement of the fuel filter is as follows:
1. First of all, we first understand the role of the fuel filter. The main function of the fuel filter is to filter the impurities in the gasoline, so that the fuel that enters the combustion engine is clean, burns more fully, reduces the formation of carbon deposits in the cylinder, and provides better power input;
2. Long-term failure to replace the fuel filter will cause the filter element inside the fuel filter to be too dirty and fail to filter. Severely, it will cause the gasoline to be blocked, the vehicle cannot be started or it is stalled during driving, so the gasoline filter needs to be replaced regularly;
3. There are two types of fuel filters for vehicles, one is a built-in fuel filter and the other is an external fuel filter;
4. The built-in fuel filter is usually together with the gasoline pump and is installed in the fuel tank because it is troublesome to replace and the cost is relatively high. Generally, it is replaced once every 100,000 kilometers. The external fuel filter is usually installed on the gasoline pipeline. It is more convenient to replace. Generally, it is replaced every 2W kilometers.