What is the purpose of a motorcycle auxiliary water tank?
2 Answers
The auxiliary water tank serves as a liquid reservoir. When the coolant expands due to high water temperature, the excess coolant flows into the auxiliary tank. Conversely, when the water temperature drops, some coolant returns to the cooling system through the pipeline. Below is a relevant introduction to the auxiliary water tank: 1. Function: When the engine temperature rises and the liquid expands, a portion of the coolant flows into the auxiliary tank through the radiator cap. When the temperature decreases and the cooling system pressure becomes negative, the system draws coolant from the auxiliary tank back into the cooling system via the radiator cap. Additionally, the auxiliary tank has corresponding markings indicating the liquid level, providing a clear indication of whether the current water level is sufficient. 2. Working principle: Thermal expansion and contraction. During vehicle operation, the increase in water temperature raises the internal pressure of the radiator, causing some water to flow out through the diversion pipe connected to the upper water chamber of the radiator. When the vehicle stops, the radiator's temperature drops, reducing the internal pressure, which allows the water in the auxiliary tank to flow back into the radiator.
I've been riding motorcycles for almost twenty years, and the role of the coolant overflow tank is quite significant. When the engine heats up, the coolant expands, and the excess is pushed into the overflow tank for storage. Once the bike cools down, the coolant contracts, and it gets sucked back in. This maintains a stable coolant level in the entire cooling system, preventing excessive pressure that could lead to hose bursts or leaks. Without the overflow tank, the expanding coolant would have nowhere to go, potentially spraying out and causing harm to people or damaging the bike. It's especially crucial during long summer rides when engine temperatures fluctuate significantly—the overflow tank helps prevent overheating. Additionally, regular checks of the coolant level are essential. Usually, there are marked lines on the overflow tank to ensure the level stays between the min and max. If the level is too low, air may enter the system, affecting cooling efficiency; if it's too high, it may overflow and waste coolant. In short, though small, this component is vital for safety. I make it a habit to check it during every maintenance session—never overlook it.
