The cooling system of a car may seem to work fine without any additional equipment attached to it, but that will not save your vehicle’s cooling system from any environmental damage like rust due to the way coolant works in a radiator.

Rust can be formed inside your car’s cooling system due to air getting into the radiator after the engine has cooled down.

When the coolant cools after the engine has been turned off, it contracts in volume, resulting in a drop of temperature and pressure inside the radiator, allowing the air to enter the radiator through the radiator cap.

That air will result in the formation of rust in the cooling system when it comes into contact with the metal in the system.

When rust has formed inside the radiator, you will have no choice but to flush out the system and replace the antifreeze. However, a radiator coolant overflow tank can prevent this problem before starting. This saves you the expense of frequent coolant replacements and possibly the expensive cost of replacing a radiator or other components of the cooling system.

How a Radiator Overflow Tank Works

The radiator overflow tank is a relatively simple device, but it can save you money by preventing rust from forming in your car’s cooling system. When the engine is running at its optimum performance, it needs the engine coolant to keep it operational.

The engine coolant absorbs the heat from the engine. When this coolant heats in the radiator, it begins to expand, causing an increase in the pressure in the cooling system of that vehicle.

When the pressure of the coolant in the radiator surpasses the designed pressure of the radiator cap, the antifreeze passes the radiator cap seal. It flows into the coolant reservoir overflow tank through the overflow tube.

When the engine has been turned off, the coolant will also start to cool down. As it cools down, it will contract in volume as well, and this decrease in volume will result in a vacuum because of a pressure drop.

Due to this vacuum, a vacuum valve in the radiator cap opens, allowing the coolant which was flown into the radiator coolant overflow tank back into the radiator.

In older vehicles with no coolant overflow bottle, the air is sucked into the radiator instead of coolant, resulting in rust formation. So, installing an overflow tank in your car is an excellent way to maintain your car’s cooling system and save repairs and replacement expenses in the long run.

If you have more questions about your coolant overflow system, give us a call at KB Motorsports! Our technicians are standing by to answer any questions you have about your coolant system.