Engine cylinder head gasket, referred to as cylinder gasket, is an elastic sealing element placed between the cylinder block and the cylinder head. Since it is impossible to be absolutely flat between the cylinder block and the cylinder head, a cylinder head gasket is required to prevent high-pressure gas, lubricating oil and cooling water from escaping from between them.

The water tank cover should be opened when draining the water. The water tank cover is mainly used to tightly cover the water inlet of the water tank, so that the engine cooling system forms a completely closed circulating cooling system isolated from the atmosphere. When discharging the cooling water, if the water tank cover is not opened, part of the cooling water can flow out, but because the water tank cover is closed, as the water volume in the radiator decreases, a certain degree of vacuum will be generated in the system, thereby slowing down the water flow or stopping the water discharge , causing the cooling water in the engine cooling system to not be completely drained, resulting in frost cracking and damage to parts.

Remove the clutch assembly in the gearbox body: first remove the coupling bolts between the clutch cover and the flywheel, and then remove the clutch from the flywheel.
Carefully observe the structural characteristics of each component, and be familiar with the names and functions of each component. Also after learning how it works, clean it and assemble it as required.

First unscrew the external screws, then remove the transmission casing, and observe the installation position of the transmission and its connection with the engine. Understand the structural characteristics of the transmission control mechanism, observe the transmission mode of each gear, and then remove the gears to clean the transmission. After cleaning, reassemble the parts after the teacher explained the working principle in detail.

1. The water tank cover should be opened when draining the water. The water tank cover is mainly used to tightly cover the water inlet of the water tank, so that the engine cooling system forms a completely closed circulating cooling system isolated from the atmosphere. When discharging the cooling water, if the water tank cover is not opened, part of the cooling water can flow out, but because the water tank cover is closed, as the water volume in the radiator decreases, a certain degree of vacuum will be generated in the system, thereby slowing down the water flow or stopping the water discharge , causing the cooling water in the engine cooling system to not be completely drained, resulting in frost cracking and damage to parts.

2. Water should not be released immediately when the temperature is high. Before the engine is turned off, if the water temperature of the engine is very high, the engine should not be stopped immediately to drain the water, so as to avoid the sudden drop in temperature of the cylinder block, cylinder head, and the outer surface of the water channel in contact with the water, which will cause a large difference in internal and external temperature and cause the cylinder block, cylinder The cover is cracked. The correct way is: unload the engine first, let the engine idle for a few minutes, and then turn off the water when the water temperature drops to 40°C to 50°C.

3. Turn off the flame after drying the residual moisture. In the cold winter in the north, if the engine cooling water cannot be completely drained, it is very easy to cause the engine body, water pump, water seal and other components to freeze and crack due to freezing and expansion of stored water. Therefore, the cooling water in the cooling system must be completely drained according to the correct method of draining water. The correct way is: after the engine has drained the water, start the engine and run it at idle speed for a few minutes, and use the engine temperature to dry the remaining water in the body, water pump, etc. When it is extremely cold, when the engine water temperature drops to 40°C to 50°C, the engine can be ignited to release water at idle speed to prevent the phenomenon of freezing while discharging water, which will cause dirty cooling water discharge and cause parts to freeze and crack.