Tractor maintenance and repair require attention to the following eight external holes, which must never be blocked:
1. A blocked fuel injector return hole will cause the needle valve to malfunction, resulting in uneven fuel supply and unstable engine operation.
2. A blocked airflow hole in the thermostat main valve will prevent the complete venting of gas from the engine's water jacket, preventing the water tank from filling completely and easily causing overheating. In cold winters, hot water cannot enter the water tank, potentially damaging it.
3. A blocked water pump drain hole will cause water seal leakage, allowing water to enter the water pump bearing housing, hydrating the grease, reducing lubrication performance, and damaging the water pump bearing.
4. A blocked dust vent in the air filter cover will prevent airborne dust particles from escaping, easily clogging downstream filters, reducing air intake, decreasing power, and even allowing dust particles to enter the combustion chamber, accelerating wear on valves, cylinder liners, pistons, and other components. Fifth, a clogged crankcase vent causes the oil in the oil pan to thin and deteriorate, reducing its lubricating performance and leading to oil burning, thus increasing oil consumption.
Sixth, a clogged drain hole at the pushrod and pushrod sleeve of the oil pump will cause the oil in the oil sump of the oil pump to increase, thin, and overflow.
Seventh, a clogged small hole in the battery cover will prevent exhaust gases from escaping in time, damaging the battery.
Eighth, a clogged small hole at the bottom of the clutch housing, coupled with a leaking rear crankshaft oil seal, will leave oil in the clutch, causing clutch slippage.
