Liquid Coolant Systems
Internal combustion engines create energy by igniting a fuel source with a spark, as a result of this process, heat is produced. A cooling system is required to reduce the amount of heat that remains trapped within the engine. Without a cooling system, an engine would quickly overheat which could result in major mechanical damage.
Today's vehicles use a liquid coolant system, a liquid coolant system circulates coolant to maintain an engine's proper operating temperature. There are many components within the cooling system that need to be routinely inspected and maintained to ensure that the cooling system functions properly.
The primary component of a liquid coolant system is the coolant, coolant has two parts, the first is antifreeze and the second component is water. The two are most commonly combined in a 50/50 ratio, this allows for adequate protection against freezing in the winter. In some areas that have colder temperatures during the winter a combination such as 70/30 may be desired for added freeze protection. If a higher antifreeze to water ratio is used during colder months, it should be reduced to a 50/50 ratio for the summer, as antifreeze cools less efficiently than water.
There are two basic types of antifreeze, the traditional glycol based and the newer Organic Acid Technology (O.A.T.). O.A.T. antifreeze contains rust inhibitors that allow for an extended service range of 100,000 miles versus traditional antifreeze's average of 30,000 miles. If either coolant is used longer the manufactures recommended service range, corrosion can accumulate and cripple the vehicles cooling system.
The water pump is the heart of a liquid coolant system, it continually circulates the coolant through the engine. The water pump is located at the front of the engine and is mechanically driven by a serpentine belt or in older vehicles the water pump has a dedicated belt running from the crankshaft pulley directly to the water pump pulley.
The heater core is not a key component to the coolant system, but it is a vital component to the comfort of a vehicle's occupants during winter months. Hot coolant flows through the heater core and a fan forces air over the heater core, this process produces the heat that you enjoy while sitting in your vehicle.
Another key coolant system component is the thermostat, the thermostat remains closed until the coolant temperature rises, and then the thermostat opens and allows hot coolant to flow to the radiator. Without the thermostat the coolant would remain cool and the heater core would not be able to adequately heat the vehicle.
There are two components that work and are many times mounted together; they are the radiator and the fan. The radiator uses aluminum, copper or brass tubing surrounded by aluminum fins that create a large surface area to dissipate heat quickly from the coolant. The fan pulls outside air through the vehicles grill and across the radiator to add additional cooling power.
Fans are either mechanical or electrical, a mechanical fan is driven by a belt from the crankshaft pulley and an electrical fan is control by a sensor that turns the fan on only when the engine coolant reaches a specified temperature. Electric fans are much more efficient than their mechanical counterpart. Electric fans spin faster, moving more air than mechanical fans and since they run independent of the engine, electrical fans increase horsepower and fuel economy.
Hoses are vital to the overall performance of the liquid cooling system, without hoses the coolant would be unable to circulate from the engine to the radiator and heater core. Hoses can be made from a wide variety of materials, with rubber being the most prominent. The cooling systems hoses can fail for numerous reasons, dry rot and cuts are two of the most common. Thoroughly inspect the hoses regularly and also check the hose clamps to make sure that they are tightened.
There are other components that are vital to the overall safety of a liquid cooling system; they include the relief valve (generally part of the radiator cap) and the overflow. The relief valve, common on older vehicles, releases when the cooling system pressure exceeds the safe limit set by the vehicle manufacturer.
In contrast the overflow, instead of release excess fluid into the environment, contains the pressure within a plastic housing. Since none of the coolant is released into the environment, the overflow is a better option as coolant is hazardous to people, animals and the environment.
