Expansion Tank
An expansion tank is found under the hood of your vehicle and is used to retain the coolant that is forced out of your radiator by pressure caused from running your car’s engine. A vehicle’s temperature rises as the engine runs. When that pressure builds to a specific point, the radiator cap will force the coolant into the expansion tank through a small tube. Once the vehicle’s engine cools, the coolant is returned to the radiator. This typically takes a couple of hours. If a vehicle was not equipped with an expansion tank or coolant reservoir, anti-freeze and water would simply be spilled out onto the road whenever the pressure in the radiator reached a specific point.
Coolant is typically a combination of anti-freeze and water. Anti-freeze is made from chemicals such as anticorrosion compounds and ethylene glycol. This solution can be very dangerous to animals when drank so having an expansion tank to prevent spilling the solution on the ground or on the road is very important. When the mixture of anti-freeze and water is heated it expands. The expansion tank is a storage space for the coolant when it is heated. It is typically made from plastic and connects directly to the radiator via a small rubber tube. This is known as the overflow tube.
Not every vehicle on the road will have an overflow or expansion tank and the tank itself is not completely necessary for a vehicle to be driven. It does however help to keep the vehicle from overheating due to loss of coolant. If you do not have an expansion tank on your vehicle and heated coolant spills out onto the road while you are driving, you run the risk of running your car’s engine without enough coolant to keep it protected. If you have an expansion tank on your vehicle then your radiator will always be filled as the extra fluids in the reservoir or expansion tank will ensure that there is always enough coolant to safely run your vehicle’s engine. The expansion tank is also very helpful in removing air bubbles from the coolant which allows the coolant to absorb heat much more effectively.
Vehicle engines generate very high levels of heat due to the combustion process. Having a properly working cooling system which includes a properly functioning expansion tank can help to keep your engine from overheating. Allowing your engine to overheat can cause damage to your vehicle that could cost thousands of dollars to repair. The complete cooling system of a vehicle is made up of several different components that all work together to maintain the temperature of your engine.
For older vehicles that did not come equipped with a standard expansion tank, an aftermarket expansion reservoir can be installed. This installation is fairly easy and can typically be completed in just a matter of an hour or so. You will need to first purchase an aftermarket expansion tank and then find a place near your radiator to install the tank. Next, you will need to find and purchase an overflow tube to connect the expansion tank to your radiator. You may also need to purchase a replacement radiator cap to ensure that the new coolant system is working properly.
In order to fill your expansion tank you will need to first allow your engine to completely cool. Once the engine is cooled, simply prop open your hood and find the expansion tank. You will need to lift the cap. This is typically done by simply pulling up on the cap. Now you will simply need to fill the expansion tank up to the fill line that should be marked on the side of the tank. Be certain that you do not overfill the tank and you may want to consider wearing safety goggles to ensure that you do not splash coolant into your eyes.