In this video, each component of the cooling system is removed from a 2001 Toyota Corolla and cut into pieces to demonstrate what's inside and how it works.

The cooling system is responsible for regulating engine temperature during operation. Maintaining optimal temperature is key to efficient combustion.

As the engine produces heat, coolant circulates inside the engine block, absorbing the heat. Hot coolant is piped through the radiator hose to the top of the radiator.

The radiator cap is responsible for building pressure inside the radiator to roughly 15PSI. This increases the heat capacity of the coolant. An overflow reservoir is attached to the top of the radiator as coolant warms and expands out. When cooled, the coolant will get sucked back into the radiator.

The hot coolant then flows across many tubes in the radiator, exchanging heat with the surrounding air. This is aided by electric cooling fans, and the vehicle driving through the air at speed.

Near the bottom of the radiator is an encased tube that runs automatic transmission fluid through it, to help cool the transmission.

The coolant then makes its way through the lower radiator hose, where the thermostat controls the flow of coolant in the engine. The cooling system is self regulated and is not controlled by the ECU directly (with the exception of the cooling fans).

The coolant finally makes its way back to the water pump, where it is pumped back through the engine block and cycled again.

There are separate circuits for the throttle body and heater core that take heat from the engine block.