|
Several cooling systems make use of a clear plastic container,
which is connected to the overflow tube from the radiator. This
container provides extra storage space for the coolant when it
expands and is called the expansion, or overflow tank. It is also
known as the coolant reservoir, or overflow canister.
As the engine heats up, the coolant inside it expands. Without the
expansion tank, the coolant would flow out of the overflow tube and
be lost from the cooling system onto the street. Instead, the coolant
flows into the expansion tank.
Since a vacuum is created in the cooling system when the engine
cools, the vacuum causes some of the coolant in the expansion tube to
be sucked back into the system. Because a cooling system with an
expansion tank is virtually a closed system, the coolant can flow
between the system and the expansion tank as it expands and
contracts. This way, no coolant is lost if the system is functioning
properly.
Another function of the expansion tank is to remove air bubbles from
the cooling system. Coolant without air-bubbles is much more
efficient than coolant with air bubbles, because it absorbs heat much
faster.
The advantage of the expansion tank is that while the level of
coolant contained in it rises and falls, the radiator is always full.
Older cars can easily be fitted with expansion tanks, simply by
mounting the tank near the radiator, connecting it to the overflow
tube, and replacing the radiator cap.
|
