Water-cooled engines are widely used in tricycles, and the system adopts forced cooling cycle. In the market due to the use of unqualified coolant and incorrect coolant adding method lead to water cavity blockage, coolant does not circulate phenomenon occurs from time to time, resulting in high engine temperature, piston top burning through, burning piston ring and other accidents. It has brought great trouble to users and maintenance personnel. This paper explains the matters needing attention in the use of coolant.

1. Before filling antifreeze, the engine cooling system must be cleaned carefully. Because the antifreeze is added with descaling agent and cleaning agent, if the engine cooling system is not carefully cleaned before use, after the antifreeze is directly added, the original scale in the engine cooling system will fall off after contacting the antifreeze, causing the antifreeze The liquid becomes turbid, thickened, or even discolored or stale. In severe cases, the water pipe, water channel or precipitate in the lower elbow joint of the water tank will be blocked, resulting. In order to prevent the occurrence of these phenomena, before adding antifreeze, you should soak the water tank with 10% caustic soda aqueous solution for one hour, then discharge the flushing fluid, and then repeatedly rinse with softened water for 2-3 times to remove the accumulated scale in the engine cooling system. Antifreeze can only be added after flushing.

      2.Before adding antifreeze, check the engine cooling system for leakage, and remove it in time before using antifreeze.

      3.It is forbidden to directly add antifreeze mother liquor. Some drivers and repairers think that the purer the antifreeze, the better, and the greater the concentration of ethylene glycol, the better, and directly add the antifreeze mother liquor. This will not only fail to meet the freezing point requirements of the antifreeze, but will cause some unexpected phenomena., Such as deterioration of antifreeze, high concentration, high density, increased low-temperature viscosity, and high engine temperature. Therefore, when using antifreeze mother liquor, it must be modulated as required and direct use is prohibited.

      4.Regular inspection shall be carried out during the use of antifreeze. The validity period of antifreeze is generally 4 years, so there is continuity in use. In order to reduce waste, do not replace the antifreeze at will after filling. However, regular item checks should be carried out on antifreeze in use. Antifreeze can be inspected every year in combination with seasonal maintenance. The inspection content should include freezing point inspection and specific gravity inspection. At the same time, the appearance inspection of the antifreeze in use should also be carried out. It is found that the specific gravity increases, the antifreeze becomes thicker, the freezing point rises, and the antifreeze becomes turbid, deteriorated, tasty, foaming, etc

      5.Antifreeze produced by different manufacturers cannot be mixed. Mixing is easy to corrode the engine and water tank

      6.Avoid using natural water instead of antifreeze in summer, because antifreeze also has anti-rust function. If natural water is used instead of antifreeze, it will accelerate the corrosion of water tank, cylinder block and other parts and produce scale, causing poor engine heat dissipation, leading to high temperature and shortening Engine service life.

      7.If general natural water is added for special reasons, when replacing the antifreeze, it is necessary to idle the engine after starting to ensure that the engine water pump and the reserved natural water below the drain pipe are fully discharged.