How to Read a Cooling System Diagram

Knowing how to read a cooling system diagram is important if you want to able to do regular maintenance work on your car yourself. The cooling system in your car is responsible for ensuring that the engine does not get overheated. A cooling system in a car is essential because most of the energy from the fuel is converted into heat, and in the absence of a cooling system, there will be no outlet for all that heat. That said; the cooling system has a host of other functions, critical to the smooth running of your vehicle.

An important aspect of the cooling system is to enable the engine to heat up quickly. This is because your car’s optimum performance requires that the engine run at a high temperature. It is the cooling system that ensures the engine heats up to and stays at the required temperature. Any cooling system will have certain key components, and the most important goal of the cooling system is to move the coolant through the engine so that heat is dissipated.

In order to be able to read a cooling system diagram, it is necessary to understand what the common elements shown in the figure are and how they work.


This is the most important component of the cooling system. The coolant that has been transferred from the engine is pumped through the radiator tubes and is then cooled off for the next round.

Radiator Hoses

As important as your radiator is, the rubber hoses (top and bottom) connected to it are equally important, as fluids are transported through the cooling system through them. You need to ensure that these hoses are in good condition, and if you spot any cracks or damage, it is best to replace them as soon as possible.

Water Pump

As the name suggests, the water pump is responsible for pumping the coolant throughout the cooling system. Apart from race cars, all other cars have a water pump that is belt driven.

Thermostat and Thermostat Housing

The thermostat is critical to the working of the cooling system because your car engine does not have a constant temperature. The thermostat in the cooling system ensures that the coolant flow in the system is regulated in keeping with the engine requirement.

Electric Cooling Fan

The electric cooling fan is intended to assist the coolant. When your car is moving at a slow speed, the electric fan sucks out air from the radiator to keep the engine cool.

Thermo-time Switch

Simply put, this is the switch for the electric fan. It is a temperature sensor that alerts the electric fan when the radiator needs to cool down.

If you were to look at a cooling system diagram, you will be able to spot the radiator, and next to it, will be the thermostat. The belt driven water pump is connected to the crank shaft of your vehicle’s engine. Then, you have the rubber hoses from the radiator that branch off around the engine to cool it. These tubes are also connected to the core of the car’s heater. The tubes join back together into the radiator. The radiator of a car engine doubles up as a reservoir as well as a heat exchanger.