What are the functions of the expansion tank?
2 Answers
The main functions of the automotive expansion tank are as follows: 1. The expansion tank serves as an auxiliary to the radiator and is an important component of the cooling system. 2. The radiator generates certain pressure when the temperature fluctuates, and the expansion tank plays a regulatory role. 3. There are corresponding markings on the expansion tank indicating the liquid level, which helps to visually know the current water level in the radiator. Below is an introduction to how the expansion tank works: Thermal expansion: When the car is running, the increase in water temperature causes the air pressure inside the radiator to rise, so some water (more precisely, water vapor) will flow out through the diversion pipe connected to the upper water chamber of the radiator; 1. Cold contraction: When the vehicle stops working, the temperature of the radiator decreases, and the internal air pressure of the radiator decreases, so the water in the expansion tank (or the water storage device connected to the diversion pipe 2) will flow back into the radiator.
The auxiliary tank primarily serves to receive excess coolant when the engine is running and the temperature rises, preventing excessive system pressure. During my daily driving, I've noticed that if the auxiliary tank's fluid level isn't checked promptly, air may enter the system, causing engine overheating. It also acts as a safety buffer, with coolant flowing back to replenish when temperatures drop, maintaining pressure balance. During maintenance, I make it a habit to regularly check if the cap is sealed to prevent leaks and rust. After being connected to the main radiator, it can extend engine life and reduce repair costs. Taking a quick glance at the fluid level before driving can help avoid overheating incidents on the road.
