The engines of tractors and agricultural transport vehicles are equipped with air filters, oil filters, and diesel filters, commonly known as "three filters". The operation of the three filters directly affects the performance and service life of the engine. At present, a considerable number of drivers do not perform the required maintenance and upkeep of the "three filters" at the required time and regulations, resulting in frequent engine failures and premature entry into the maintenance period.

Key points for air filter maintenance and upkeep. In addition to maintaining the air filter according to the prescribed time and operating requirements, the following points should also be noted:
1. The guide grille of the air filter should be maintained without deformation or rust, and its inclination angle should be 30-45 °. If it is too small, the resistance will increase, affecting the intake. If it is too large, the airflow rotation will weaken, and the ability to separate dust will decrease. The surface of the blades must not have paint peeling off to prevent oxidation particles from entering the cylinder. The direction of the dust outlet should be based on the ability to discharge dust particles.
2. During maintenance, clean the ventilation mesh holes; For those with dust collection cups, the height of dust particles should not exceed one-third, otherwise they should be removed in a timely manner; The sealing of the dust collection cup should be tight, and the rubber sealing strip should not be damaged or lost.
3. The oil level height of the fine filter should comply with the standard regulations. If it is too high, it will cause the oil to enter the cylinder and accumulate carbon. If it is too low, it will reduce the filtering effect and accelerate wear.
4. For the metal mesh (wire) used as a substitute in the fine filter, the hole or wire diameter can only be slightly smaller and cannot be increased, and the filling amount cannot be reduced, otherwise it will reduce the filtration effect.
5. There should be no air leakage in the intake pipeline, and oil replacement and cleaning should be carried out in a place without wind or dust; Blowing the filter should be done with high-pressure air in an environment with low humidity, and the blowing direction should be opposite to the direction in which the air enters the filter; During installation, the folding directions of adjacent filter screens should cross each other.

Key maintenance points for oil filters. The oil filter must be maintained according to the prescribed time and pay attention to the following points:
Centrifugal oil filter. Special attention should be paid to the installation after disassembly and cleaning when maintaining the centrifugal fine filter:
① There should be no jamming phenomenon. The inspection method is to reassemble the rotor and rotate it with force by hand. After letting go, the rotor can rotate freely for 2-3 turns before stopping, which is considered qualified;
② You can also install the fine filter on the car, start the engine, run it at the rated speed for a few minutes, and when the oil temperature reaches 70 ℃, turn off the engine. At this time, listen outside the casing to hear the rotor continue to rotate for more than 1.5 minutes, which is considered qualified installation. If the above indicators are not met, it indicates that the installation is not qualified and should be reassembled.