During the operation of a tractor, wear and aging of its components are inevitable, leading to a deterioration in its technical condition, a decrease in power, an increase in fuel consumption, and a constant occurrence of malfunctions. In order to prevent malfunctions, timely and correct maintenance and upkeep of tractors are necessary to extend their service life and reduce operating costs. During the investigation of the technical status of agricultural tractors, it was found that the maintenance and upkeep of some parts were not given due attention, resulting in many adverse consequences.

Neglecting the maintenance of diesel filters

The diesel filter has always played the role of a cleaner, with its main function being to filter out particulate impurities and moisture from diesel, ensuring the normal operation of the engine. But there are also many diesel car drivers who believe that every time they add diesel, it has been deposited for a long time, and the impurities and water in the oil are already very clean. Therefore, they choose to give up installing or not maintain the diesel filter for a long time. In fact, this often leads to small losses.

Diesel filters should be inspected, cleaned or replaced after 200-300 hours of use. Pay attention to the following points:

(1) There should be no air leakage in the sealing parts of the air filter assembly. When installing the sealing ring, do not twist it and install it firmly.

(2) Regularly clean the filter element. Paper filter elements cannot be cleaned with diesel and must be brushed off with a soft bristled brush or blown back with an air cylinder. When the filter element is broken or blocked, it should be replaced. The oil bath air filter should be regularly replaced with engine oil, the oil pan should be cleaned, and the oil should be added to the appropriate height, not too full or too little.

(3) After disassembling and maintaining the filter, reassembling it and installing it on the tractor, the air inside should be drained completely.

Long term non replacement of valve springs

Due to the high temperature experienced by the valve spring, long-term non replacement can easily cause annealing, resulting in insufficient elasticity. Meanwhile, due to the constant alternating stress on the valve spring, long-term non replacement may result in plastic deformation, leading to a shortened free length and insufficient elasticity. The result of insufficient elasticity will inevitably lead to slow valve movement, delayed closing, and also result in loose valve closure, leading to insufficient cylinder pressure.

Neglecting the maintenance of small holes

(1) Not attaching importance to the role of starting the spray hole. Long term failure to remove carbon deposits in the startup nozzle can cause blockage or blockage of the nozzle. The function of starting the nozzle is to enable diesel to be directly injected into the cylinder through the nozzle earlier, and first ignite and burn in the main combustion chamber to increase the temperature inside the cylinder and improve the combustion conditions of the mixed gas in the main combustion chamber. Therefore, if the starting nozzle is not smooth or blocked, it will worsen the starting conditions and lead to difficulty in starting.

(2) Fuel tank cap vent hole. After the hole is blocked, the fuel tank is no longer connected to the atmosphere, and negative pressure will occur in the upper part of the tank due to the decrease in oil level, causing fuel supply interruption; After the fuel is heated and evaporates, the pressure inside the fuel tank increases, which can cause oil leakage at the fuel tank switch. Therefore, this hole cannot be blocked.

(3) Crankcase air change hole. When the engine is working, there is always a certain amount of exhaust gas leaking into the crankcase through the piston rings. After using the oil engine for a long time, with the wear of the cylinder liner and piston ring, the clearance increases, the elasticity of the piston ring decreases, and more exhaust gas leaks into the crankcase. After the air change hole is blocked, the exhaust gas inside the crankcase accumulates more and more, and the air pressure inside the crankcase increases, which will cause oil leakage. High humidity exhaust gas will mix into the oil, accelerate oil deterioration, and accelerate mechanical wear. Therefore, it is necessary to clear this hole during maintenance.

(4) Oil pump drain hole. The blockage of the oil drain hole on the fuel pump can cause a small amount of diesel to leak into the fuel injection pump between the push rod and the conduit, diluting the lubricating oil in the housing and accelerating the wear of the parts. Therefore, this hole cannot be blocked.

(5) Water pump drain hole. If this hole is blocked, the leaked water cannot be discharged from the pump body and enter the bearing seat, which will accelerate the damage of the bearing. Therefore, it is necessary to clear this hole during maintenance.

(6) The oil spray holes on the cylinder head cover have not been unblocked for a long time. Due to factors such as unclean engine oil, it is easy for the spray holes to become blocked or obstructed, resulting in poor lubrication and rapid wear of parts such as valves, valve guides, and rocker arms. This can lead to problems such as loose valve closure, insufficient intake, unclean exhaust, and decreased power.

Long term non adjustment of valve clearance

When the engine is working, the valves and valve transmission components will expand due to temperature rise. If the engine does not use hydraulic tappets, there will be no gap or too small gap between the valves and valve transmission components in the cold state. In the hot state, the valve will not close tightly due to the thermal expansion of the valves and their transmission components, causing air leakage during compression and power stroke of the engine. Therefore, normal valve clearance is essential. The adjusted valve clearance may also increase due to wear and tear of the valve train components, resulting in reduced valve lift, insufficient inflation, poor exhaust, and abnormal knocking sounds. Therefore, after using the tractor for a period of time, the valve clearance should be checked and adjusted.

5. Cooling scale is not removed all year round

Failure to remove scale all year round can lead to excessive scaling, deterioration of the body's heat dissipation performance, resulting in high engine temperature, thinning and deterioration of engine oil, decreased mechanical strength of parts, and early wear of components. At the same time, it will also reduce intake and decrease power; Excessive expansion of parts can affect their normal technical performance, and in severe cases, phenomena such as tile burning and shaft hugging may occur. To this end, before maintenance, fill the cooling system with a solution prepared in a ratio of 10 L of water, 750 g of caustic soda, and 250 g of kerosene. After running the engine at medium speed for 5-10 minutes, leave the solution for 10-12 hours (note: keep warm or work continuously in winter to prevent freezing), then restart the engine at medium speed for 5-10 minutes, release the washing solution, and carefully rinse it with clean water.

6 Neglecting the maintenance of the oil filter

After a period of use, the engine lubrication system is mixed with metal shavings and other mechanical impurities generated by the friction of engine parts, as well as gum produced by the engine oil itself. If these impurities enter the lubricating oil circuit with the engine oil, they will accelerate the wear of engine parts and may also block oil pipes and passages. In order to prevent these impurities from entering the main oil passage, an oil filter is installed in the engine lubricating oil circuit. The oil filter should be replaced once every 7500 kilometers of vehicle travel. For vehicles that frequently drive on harsh road conditions, the oil condition should also be checked regularly, and the deadline for replacing the oil filter should be shortened if necessary.