As performance increases, heat generation increases, and to reduce engine noise, “water-cooling” is the norm for modern engines. The cooling medium is a long-life coolant (commonly known as LLC), but keep in mind that it is not OK to fill the radiator cap to the brim and that LLC must be replaced periodically.
Here, we focus on the coolant in water-cooled engines, where the needle on the water temperature gauge now points higher than before.
- Use good LLCs and cleaning agents.
- Don’t just pull the drain and flush it out! Actively drive it out.
- Blow compressed air backward to check the situation.
Use good LLCs and cleaning agents.
How often should coolant = LLC be replaced? For large vehicles, it is normal to replace the coolant every two years for vehicle inspections. Especially for younger models, it is advisable to replace the coolant as early as possible in order to know the internal condition of the engine from various angles. When the coolant is drained, if it is dirty or the color of the LLC has faded, it is time to perform a flushing practice. If the inside of the radiator and cooling passages become dirty, the original cooling performance will not be achieved.
Don’t just pull the drain and flush it out! Actively drive it out.
It is best to change the coolant when the engine is cooling down after warming up, as with an oil change, not when the engine is hot or completely cool. When the engine is hot, it is not advisable to touch or loosen the radiator cap directly with the fingers, as this will cause burns and hot coolant to spurt out. While the engine is cooling down, remove the coolant drain bolt and then the radiator cap. To determine the condition of the coolant in the coolant passages, prepare a bucket and then drain the coolant. If it drips on the ground, it will be difficult to determine the condition. After removing the coolant, insert a water hose into the radiator inlet and apply pressure to clean the inside of the cooling passages. After that, apply an air gun to the inlet and blow air inside the cooling channel as if covering the mouth with the palm of your hand.
Blow compressed air backward to check the situation.
Blow air not only from the radiator side but also from the drain side, and confirm that water vapor rises from the radiator cap side. If, for example, the inside of the radiator passage is sludged with hot water stains, you can see the hot water stains splashing around the radiator cap during this operation.