1. Check the pump

　　冷却系统冷却水连续循环的动力来源是泵。泵能否产生足够的压力是冷却系统能否正常运行的关键。当加入冷却水时，冷却液位随着发动机转速的增加而显著降低，说明泵工作正常。反之，泵与叶轮可能松动，冷却水不能循环。在国内叉车知识型发动机中，泵、发电机和冷却风机共用一条皮带，皮带的松紧程度直接影响泵、风机和发电机的转速。用手指按下腰带中部，较低的挠度应正常在11-13mm(CPC3L型号)。如果它太大，水温就会太高;如果太小，水泵轴承和发电机轴承会损坏。

　　The power source of continuous cooling water circulation in cooling system is pump. Whether the pump can generate enough pressure is the key to the normal operation of the cooling system. When cooling water is added, the cooling liquid level decreases significantly with the increase of engine speed, indicating that the pump works normally. Conversely, the pump and impeller may be loose and the cooling water can not be circulated. In domestic forklift knowledge-based engines, pumps, generators and cooling fans share a belt. The belt tightness directly affects the speed of pumps, fans and generators. Press the middle part of the belt with your finger. The lower deflection should be between 11 and 13 mm (CPC3L). If it is too big, the water temperature will be too high; if it is too small, the bearing of pump and generator will be damaged.

　　2. 检查散热器

　　2. Check the radiator

　　叉车百科全书的散热器位于车辆后部。叉车底盘知识低，工厂工作环境差，散热器表面容易堆积杂物和灰尘，如不及时清理，将严重影响散热效果。日常使用后，应仔细清洗散热器表面，避免使用高压水枪。由于散热器管壁很薄，如果清洗压力过高，容易冲凹，影响循环效果。此外，严禁使用冷却水“硬水”，防止散热器内结垢，导致冷却水添加不足。

　　The radiator of forklift encyclopedia is located in the rear of the vehicle. Forklift chassis knowledge is low, factory working environment is poor, radiator surface is easy to accumulate debris and dust, if not cleaned in time, will seriously affect the heat dissipation effect. After daily use, the radiator surface should be carefully cleaned to avoid the use of high-pressure water gun. Because the wall of radiator is very thin, if the cleaning pressure is too high, it is easy to concave, which affects the circulation effect. In addition, the use of cooling water "hard water" is strictly prohibited to prevent scaling in the radiator, resulting in inadequate addition of cooling water.

　　3.检查恒温器

　　3. Check the thermostat

　　目前，发动机使用的主要温控器是蜡温控器。其主要性能指标是恒温器在不同水温下应有不同的扬程。因此，冷却水温度是动态控制的。对于不拆装冷却系统的恒温器进行质量检查，主要通过散热器的进、出口管温差来区分。在发动机冷却机启动时间的个周期内，进气管和出气管应手工有明显的温差，工作一段时间后，温差明显减小。当发动机达到正常工作温度(80℃-90℃)时，无明显温度差。当然，准确的测试方法是取下温控器，将其放入热水中，逐渐加热，检查阀门开启温度和阀升程。

　　At present, the main thermostat used in engine is wax thermostat. Its main performance index is that the thermostat should have different head under different water temperature. Therefore, the cooling water temperature is dynamically controlled. To check the quality of thermostat without disassembling and assembling cooling system, the temperature difference between inlet and outlet pipes of radiator is used to distinguish. During the first cycle of engine cooling machine start-up time, there should be obvious temperature difference between intake and outlet pipes manually. After working for a period of time, the temperature difference decreases obviously. When the engine reaches the normal working temperature (80 - 90 C), there is no obvious temperature difference. Of course, the most accurate test method is to remove the thermostat, put it into hot water, gradually heating, check the valve opening temperature and valve lift.

　　4. 检查冷却风扇

　　4. Check the cooling fan

　　可以在散热器前面放一张薄纸来测量风扇的风量。当发动机运转时，如果纸能被吹开，那么风量就足够了。这与前发动机吸进空气的汽车风扇不同。叶片不能向后安装，风机保护盖应完整有效。

　　A thin sheet of paper can be placed in front of the radiator to measure the fan flow. When the engine is running, if the paper can be blown away, then the air volume is enough. This is different from the car fan in which the front engine sucks air. Blades can not be installed backwards, fan cover should be complete and effective.