How to deal with the abnormal water temperature of the forklift

The forklift cooling system is relatively simple in terms of structure, and generally consists of cooling fans, radiators, thermostats and other components. The cooling fan is often driven directly by the engine, and the fan speed is consistent with the engine speed. The cooling water temperature is mainly adjusted by the thermostat.

This structure is characterized by convenient maintenance and low cost. The disadvantage is that it is not sensitive to the control of the cooling water temperature. The engine water temperature is mainly related to whether the thermostat is working normally, whether the water pump can build up enough pressure, and whether the cooling fan can reach the standard speed, etc. Judging the failure of the cooling system should also start with judging whether these components are working properly.

Thermostat inspection

At present, the thermostats used on engines are mainly wax thermostats. Its main performance index is that the thermostat should have different lifts at different temperatures, so as to dynamically control the height of the cooling water temperature. To check whether the thermostat is not disassembled, it is mainly judged by the temperature difference between the water inlet pipe and the water outlet pipe of the radiator. In the first period after the engine is cold-started, there should be a significant temperature difference when touching the water inlet and outlet pipes by hand. After working for a period of time, the temperature difference is significantly reduced. When the engine reaches the normal operating temperature, there is no obvious temperature difference feeling when it is touched by hand. Of course, the most accurate way to judge is to remove the thermostat, place it in water, and gradually heat it to check the valve opening temperature and valve lift.

Pump inspection

The power source for the continuous circulation of cooling water in the cooling system comes from the water pump. Whether the water pump can build up enough pressure is the key to the normal operation of the cooling system. When adding cooling water, if the coolant level drops significantly as the engine speed increases, this indicates that the water pump is working normally. Otherwise, the pump and the impeller may become loose and the cooling water cannot circulate.

Cooling fan inspection

In the domestic forklift engine, the water pump, generator, and cooling fan share a belt, so the tightness of the belt directly affects the speed of the water pump, generator, and cooling fan. Press down the middle of the belt with your fingers. The downward deflection should be 11-13mm (CPC3L). It is normal. If it is too large, the water temperature will be too high. If it is too small, it will damage the bearings of the water pump and generator. To check the fan air volume, a thin piece of paper can be placed in front of the radiator water tank, and the paper cannot be attached to the water tank when the engine is running (the engine is behind). The fan blades cannot be installed backwards, and the fan guard is complete and effective.

Radiator inspection

The radiator of the forklift is located at the rear of the vehicle. Due to the low chassis of the forklift and the poor working environment in the factory area, some debris and dust are easy to accumulate on the surface of the radiator. If it is not cleaned in time, it will seriously affect the heat dissipation effect. The radiator should be cleaned carefully every day after the work is completed, and the use of high-pressure water guns should be avoided as much as possible. Because the tube wall of the radiator is very thin, if the cleaning pressure is too high, the tube wall will collapse, which will affect the heat dissipation effect. In addition, it is strictly forbidden to use hard water for cooling water to prevent the generation of scale and lead to insufficient cooling water.

When inspecting the above main components and judging that there is no fault, problems other than the cooling system should be considered. If there is too much carbon in the combustion chamber, the injection time of the diesel engine is incorrect, whether the cylinder head gasket is damaged or whether there are cracks in the cylinder block or cylinder liner. In short, there are many types of engine cooling system failures, but as long as you maintain a calm mind and carefully analyze the failure phenomenon, you will surely be able to find a solution.