Importance of Servicing Your Cooling System
The cooling system of any vehicle performs an important role in the life of your vehicles engine.
The cooling system consists of multiple components, included in this list are the radiator, the radiator cap, the overflow bottle, the cooling fan, the coolant hoses, the thermostat, the water pump, and the heater matrix also known as the heater core.
The Radiator begins the cycle. In most instances it sits at the front of the engine bay and is made out of steel, aluminium, plastic or any combination of each. All radiators share common characteristics. A normal radiator will have either side or top and bottom reservoirs for holding coolant with a series of thinner fins connecting both tanks. As coolant circulates through the radiator it is forced through these fins. The fins, in turn because of their placement at the front of the engine compartment, have cool air directed over them either from driving or from the cooling system fan that is normally installed on one side of the radiator. This cool air helps cool down the coolant inside the radiator.
The radiator cap is important as it has a pressure activated spring inside of it. Normal pressure of a cap varies but the most common are between 10lb and 16lb of pressure. If the cooling system develops more pressure than the cap is rated for, the spring collapses by design and releases the pressure into the overflow bottle. If this cap malfunctions you run the risk of building too much pressure in the cooling system and damaging other portions of the system which are not built to handle higher pressures than the system is rated for.
The overflow bottle has an important function. When a vehicle heats up and coolant expands it needs somewhere to go rather than just being expelled onto the roadway. The overflow acts as a catch can for the expelled pressure and any fluid that comes out with it. If the system is working as designed, then as the vehicle cools it develops a vacuum inside the system and draws the once expelled coolant back into the radiator until such a time as it needs to release pressure again.
Many cooling fans are electric now, but you can still find some vehicles powered by what is called a viscous fan. A viscous fan works with an internal clutch system and draws air over the radiator fins to aid in cooling the fluid in the radiator. If the internal clutch of the fan deteriorates you may notice the temperature gauge of the vehicle running slightly hotter than it normally did when the fan was operating properly. Electrical fans are powered by electrical sensors that tell the fan when to switch on or off. These sensors are called coolant temperature sensors and if one is faulty it can cause the cooling fan to not come on at all causing the vehicle to run much hotter than it normally would under normal circumstances.
The coolant hoses transport the coolant in the system through a large loop. The hoses are normally made of rubber and do not have an infinite life span. They should be checked regularly at normal service intervals to prevent problems at later dates.
The thermostat is another important part of your cooling system. The way a thermostat works is by an internal heat activated spring. The main goal of the thermostat is to regulate the flow of coolant through the entire system. From cold, as coolant sits in the engine block the thermostat is closed. This effectively stops the flow of coolant through the system and allows it to come up to operating temperature. Once operating temperature is reached in the engine the heat is transferred to the spring in the thermostat allowing it to open. This then allows the warm coolant out of the engine and into the radiator and cycles new cool coolant into the engine itself. This cycle carries on until all of the coolant in the cycle is the same operating temperature.
The water pump does exactly what its name implies. Its only purpose is to pump the available coolant through the entire loop of the system.
The heater matrix or heater core as it is also known is normally located behind the dashboard of the vehicle. It is a smaller version of a radiator with a centrifugal fan blowing over the fins of it. When you adjust your climate control dials or buttons to provide heat in the passenger compartment it opens a series of doors behind the dashboard to direct the airflow to the intended target area.
Those are the major components of a properly operating cooling system. When everything is working as it should your cooling system behaves normally and your engine runs at optimal temperature. When the system is not operating properly it can shorten or even end the life of your engine.
Over a period of time sediment circulates through your cooling system. This is caused by a chemical reaction which happens when aluminium parts are bolted in direct contact with steel parts and the process is called a galvanic reaction. Also steel parts in contact with water can rust internally over time creating more debris in the system. This debris can block or restrict the fins of the radiator and heater matrix. if the fins are blocked or restricted the coolant will not be able to flow in its normal loop and the vehicle can overheat causing damage to the engine itself. It is not uncommon to find a vehicle with an engine that has failed and then being able to trace the failure directly to the maintenance of the cooling system.
Coolant or anti-freeze as it is also known serves 3 main functions. Properly mixed coolant increases the boiling point of the water it is mixed with so when the vehicle is running at operating temperature it will not boil over. Coolant also lowers the freezing point of the water it is mixed with so in the colder winter months the water inside the engine block cannot freeze. If you were running plain water and it did freeze, frozen water expands, this in turn would push out on the weakest part of the engine which is normally called a core plug or freeze plug. If those plugs get pushed out then once the vehicle is started you loose the remaining coolant in the engine and then damage it from overheating. The final duty of properly mixed anti-freeze or coolant is that it has built in lubricants in it and rust inhibitors. When maintained properly these lubricate the bearings in the water pump, the springs on the thermostat and the rust inhibitors stop some of the normal corrosion that would occur if you do not service the cooling system regularly. Failure to replenish these rust inhibitors and lubricants shorten the life of the components they are there to protect which would lead to premature failure and possibly damage to the engine.
Considering all the positive reasons to have a normal cooling system service there is no reason to not have them done to protect the second biggest investment most people make in their lives. Your vehicle.