Truck engines are very delicate parts, and very small impurities can damage the engine. When the air filter is too dirty, the engine air intake is insufficient and the fuel burns incompletely, resulting in unstable engine operation, reduced power, and increased fuel consumption. At this time, the air filter, the patron saint of the engine, is particularly important in maintenance.
In fact, the maintenance of the air filter is mainly based on the replacement and cleaning of the filter element. The air filter used on the engine can be divided into three types: inertial type, filtering type and comprehensive type. Among them, according to whether the filter element material is immersed in oil, it can be divided into three types. There are two kinds of wet and dry. We explained several common air filters on the market.
01
Maintenance of dry inertial filter
The dry-type inertial air filter device is composed of a dust cover, a deflector, a dust collecting port, a dust collecting cup, etc. Please pay attention to the following matters during maintenance:
1. Frequently check and clean the dust exhaust hole on the centrifugal dust removal hood, remove the dust attached to the deflector, and pour the dust into the dust collection cup (the amount of dust in the container should not exceed 1/3 of its volume). During installation, the sealing performance of the rubber gasket at the connection should be ensured, and there should be no air leakage, otherwise it will cause a short circuit of the air flow, reduce the air speed, and greatly reduce the dust removal effect.
2. The dust cover and deflector should maintain the correct shape. If there is a bulge, it should be shaped in time to prevent the airflow from changing the original design flow direction and reducing the filtering effect.
3. Some drivers fill the dust cup (or dust pan) with fuel, which is not allowed. Because the oil is easy to splash into the dust outlet, deflector and other parts, this part will absorb dust, and ultimately reduce the filtering and separation capabilities.
02
Maintenance of wet inertia filter
The wet inertial air filter device is composed of a center tube, an oil pan, etc. Please pay attention to the following during use:
1. Regularly clean the oil pan and change the oil. The viscosity of the oil should be moderate when changing the oil. If the viscosity is too large, it is easy to block the filter of the filter device and increase the air intake resistance; if the viscosity is too small, the oil adhesion ability will be reduced, and the splashed oil will be easily sucked into the cylinder to participate in the combustion and produce carbon deposits.
2. The oil level in the oil pool should be moderate. The oil should be added between the upper and lower engraved lines or the arrow on the oil pan. If the oil level is too low, the amount of oil is insufficient, and the filtering effect is poor; if the oil level is too high, the amount of oil is too much, and it is easy to be burned by the suction cylinder, and it may cause “overspeed” accidents.
03
Dry filter maintenance
The dry air filter device consists of a paper filter element and a sealing gasket. Pay attention to the following points during use:
1. Check regularly to ensure cleanliness. When removing the dust on the paper filter element, use a soft brush to remove the dust and dirt on the surface of the filter element along the direction of the crease, and tap the end surface lightly to make the dust fall off. When performing the above operations, use a clean cotton cloth or rubber plug to block both ends of the filter element, and use a compressed air machine or an inflator to blow air out of the filter element (air pressure should not exceed 0.2-0.3MPA to prevent damage to the filter paper) to remove stickiness. Dust adheres to the outer surface of the filter element.
2. Do not clean the paper filter element with water, diesel or gasoline, otherwise it will block the pores of the filter element and increase the air resistance; at the same time, diesel is easily sucked into the cylinder, causing the limit to be exceeded after installation.
3. When the filter element is found to be damaged, or the upper and lower ends of the filter element are warped, or the rubber sealing ring is aging, deformed or damaged, replace the filter element with a new one.
4. When installing, pay attention to the gasket or sealing ring of each connection part not to be missed or installed incorrectly to avoid air short circuit. Do not overtighten the wing nut of the filter element to avoid crushing the filter element.
04
Maintenance of wet filter filter
This device is mainly composed of a metal filter dipped in engine oil. Pay attention to:
1. Clean the dust on the filter with diesel or gasoline regularly.
2. When assembling, soak the filter screen with engine oil first, and then assemble after the excess engine oil drips out. When installing, the cross frame on the filter plate of the cake filter should be overlapped and aligned, and the inner and outer rubber rings of the filter should be well sealed to prevent short circuit of the air intake.
With the development of truck technology, the use of paper-core air filters in engines has become more and more common. Compared with oil-bath air filters, paper-core air filters have many advantages:
1. The filtration efficiency is as high as 99.5% (98% for oil-bath air filters), and the dust transmission rate is only 0.1%-0.3%;
2. The structure is compact, and it can be installed in any position without being restricted by the layout of vehicle parts;
3. No oil is consumed during maintenance, and a large amount of cotton yarn, felt and metal materials can be saved;
4. Small quality and low cost.
05
Maintenance attention:
It is very important to use a good paper core when sealing the air filter. Preventing unfiltered air from bypassing the engine cylinder becomes a crucial step for replacement and maintenance:
1. During installation, whether the air filter and the engine intake pipe are connected by flanges, rubber pipes or directly, they must be tight and reliable to prevent air leakage. Rubber gaskets must be installed on both ends of the filter element; fixed air filter The wing nut of the outer cover of the filter should not be tightened too tightly to avoid crushing the paper filter element.
2. During maintenance, the paper filter element must not be cleaned in oil, otherwise the paper filter element will become invalid and easily cause a speed accident. During maintenance, you can only use vibration method, soft brush removal method (to brush along the wrinkles) or compressed air blowback method to remove dust and dirt attached to the surface of the paper filter element. For the coarse filter part, the dust in the dust collection part, blades and cyclone tube should be removed in time. Even if it can be carefully maintained every time, the paper filter element cannot fully restore its original performance, and its air intake resistance will increase. Therefore, generally when the paper filter element needs to be maintained for the fourth time, it should be replaced with a new filter element. If the paper filter element is broken, perforated, or the filter paper and the end cap are degummed, it should be replaced immediately.
3. When using, it is necessary to prevent the air filter from being wetted by rain, because once the paper core absorbs a large amount of water, it will greatly increase the air intake resistance and shorten the service life. In addition, the paper core air filter should not be in contact with oil and fire.
4. In fact, the filtration manufacturers are not encouraged to disassemble and clean the air filtration system. After all, how to clean the filtration effect will be greatly reduced.
But for drivers who are pursuing efficiency, cleaning once is to save one time. Generally, cleaning once for 10,000 kilometers, and the number of cleanings should not exceed 3 times (depending on the working environment of the vehicle and the cleanliness of the filter element). If it is in a dusty place such as a construction site or desert, the maintenance mileage should be shortened to ensure that the engine breathes and intakes smoothly and cleanly.
Do you now know how to better maintain and replace truck air filters?
Post time: Nov-25-2021