1. Causes of tractor failure

(a) Natural factors

For example, parts wear, parts vibration, machine aging, internal pollution and other factors. Due to the above factors, the gap between tractor parts becomes larger, the connection is loose, the seal is not tight, and the operation is abnormal. If not repaired and maintained promptly, it will break.

(b) Human factors

For example, poor manufacturing and maintenance quality, improper operation adjustment, etc. For example, the raw materials of manufacturing parts are poor, the accuracy is not high, and the surface finish and heat treatment do not meet the requirements; Failure to perform maintenance as required by regulations; Long-term overload operation, sudden lifting or clutch pressing, large angle change, etc. The water tank is short of water or the oil tank is short of oil, etc. These factors are not caused over a long period of time, but form in a short period of time or occur suddenly, and human factors are unpredictable.

2. Manifestations of tractor failure

(a) Loss of function

Can't start, can't lift agricultural machinery, automatically shut down, etc. Because the automatic shift exits, the generator does not charge, the oil pipe is clogged, etc.

(b) Abnormal manifestations

Such as insufficient power, unstable operation, abnormal sound, etc. It is mainly caused by factors such as parts wear, aging, and gradual shedding of parts. Usually exhibit black, white or blue smoke; Water leakage, oil leakage, lighting failure; Difficulty in starting, unstable speed, low oil pressure, ineffective clutch operation, insufficient generator power or no generation, etc. There is a shooting sound in the exhaust pipe, and there are abnormal noises in the gearbox and central transmission; The odor is the burning of rubber or friction plates or insulation.

3. Troubleshooting

(a) black, white or blue smoke

1. Black smoke is the free carbon exhaust pipe caused by incomplete combustion of fuel due to the poor state of fuel supply system, air supply system or engine compression system. First, the oil-gas ratio is improperly adjusted, the position of the plunger adjustment rod joint and the oil pump rod of individual oil cylinders moves, and the oil supply of the oil cylinder is too large. In this case, adjust the position of the cylinder plunger adjustment rod and the oil pump rod. Second, the atomization quality of the nozzle is not high, and the fuel is not completely burned, resulting in black smoke. This phenomenon is caused by the weakening or fracture of the nozzle pressure regulating spring. Third, the fuel supply advance angle is incorrect or slightly small, and the fuel is not completely burned and discharged with the air pipe. There are also factors of black smoke and air system. First, the blockage of the air filter leads to poor ventilation; Second, the exhaust gas is unclean and the combustion is incomplete, resulting in black smoke. The reason is that the valve clearance becomes larger, the valve spring is damaged, the elasticity is insufficient, or the valve deposits carbon; The third is overload operation.

2. White smoke is caused by no fuel burning, too much moisture in the fuel, or water leakage into the cylinder. The reasons for this phenomenon are as follows: First, the engine temperature is too low, and the fuel is discharged before it is completely burned, while the unburned fuel is white mist. Secondly, the gasket is damaged or burned out, and cold water enters the cylinder. Under the action of high temperature and high pressure of the cylinder, the cold water is discharged into the air duct in the form of water mist. Third, the fuel supply is not timely, the unburned fuel cannot be completely burned, and the unburned fuel is atomized out of the gas pipe. Fourth, the fuel injector drips backward, the needle valve of the fuel injector is stuck in the open position or the pressure spring of the fuel injector is broken. The oil entering the cylinder cannot be atomized and is discharged from the cylinder after incomplete combustion. Fifth, the plunger pair is worn or of poor quality, the sealing is not good, the fuel injection is delayed, and the exhaust is exhausted after incomplete combustion in the cylinder. Sixth, the fuel quality is poor, the ignition point is high, the combustion time lags behind, and the fuel is discharged from the cylinder before it is completely burned. Seventh, the fuel injector assembly is not tight, resulting in incomplete combustion of some fuel out of the exhaust cylinder. Eighth, the lubricating oil is insufficient or poor lubrication, and the valve is stuck in the open position, so that the cylinder cannot promote contraction normally, resulting in incomplete combustion of fuel.

3. Blue smoke is caused by burning engine oil. The reasons for this phenomenon are as follows: First, the cylinder taper and ovality of the compression system exceed the standard, the gap between the cylinder and the piston is too large, the opening gap and side backlash of the piston ring are too large, the opening of the piston ring coincides, the piston ring deposits carbon, the elasticity becomes smaller, and the position and direction of the torsion ring or tapered ring are incorrect; Second, the strain of the cylinder is large; Third, the gap between the valve and the valve guide is too large; Fourth, the amount of oil in the oil pan of the air filter is too high; Fifth, the oil content in the bottom shell is too high; Sixth, there is no running-in period after a new car or overhaul; Seventh, the quality of fuel is poor, and there are more adulterated oil products.

(b) Difficulty starting the engine

The main causes of engine starting difficulties are the fuel system, air filter, excessive oil buildup in the combustion chamber and insufficient cylinder compression.

1. Fuel system problems. First, the diesel is used up or the fuel tank switch is not turned on; Second, air enters the oil circuit, causing the oil circuit to be blocked; Third, the fuel pipeline or diesel filter is blocked; Fourth, the fuel injector does not inject fuel; Fifth, the plunger is seriously worn; Sixth, the needle valve seal of the oil outlet valve is damaged; Seventh, the needle and seat hole of the oil outlet valve are supported by foreign objects; Eighth, the injection pressure is too low or the fuel supply time is too long or too short; Ninth, the fuel pump does not supply fuel.

2. The air filter is mainly caused by the blockage of the air filter, exhaust pipe or silencer.

3. If there is too much oil in the combustion chamber, pull the throttle handle to the oil-free position, pull the pressure reduction handle to open the valve, turn the crankshaft and drain the oil.

4. The compression force of the cylinder is insufficient. The reasons are: First, the position of the decompression handle is wrong and it is still in the decompression position; Second, the cylinder head gasket leaks; Third, the piston ring is worn; Fourth, when the valve leaks, check the valve clearance, valve spring, valve guide and valve seat sealing.