Cooling Systems

Car Repair & Service (Cooling Systems) Molendinar | Gold Coast

At Fleet Tec Automotive we consider your Cooling System to be in integral part of your vehicle that needs to be inspected at regular intervals to help insure the longevity and reliability of the overall system. Whilst inspecting a system we inspect the condition of the overall system by testing the coolant concentrate level and also test for possible electrolysis in the coolant – This is caused by stray current that can cause the system to corrode and fail prematurely if not rectified. As well as testing for Coolant Condition, We Inspect things such as Fan Operation, Radiator and Radiator Cap Condition, Inspect for any Coolant Leaks, Inspect all Coolant Hoses and Clamps and obviously that the engine is not running hotter than recommended by Factory.

Every Car on today’s road needs a Cooling System of some sort to ensure the engine does not over heat. There are two types of Cooling Systems in the motor industry today which are water/fluid Cooled Systems and Air Cooled systems, with the most common and effective system being fluid cooled systems. In a Fluid Cooled Cooling System an Anti-Freeze/Boil Solution is added with water to help assist in the cooling process, this is also known as Coolant. As well as assisting in temperature control Coolant also acts as an anti-corrosive agent to help maintain the overall condition of the engine block and Cooling System.

The operation of a Cooling System is to dissipate heat generated by the engine. Whilst the engine is running it is constantly producing heat from the combustion process that occurs within the combustion chamber of the engine from fuel being ignited in the cylinders. The combustion of fuel dissipates heat which is then absorbed by the liquid in the surrounding area in the engine block, this is transferred through the cylinder walls into the Coolant which is forced throughout the engine by the water pump to the top of the engine into the radiator, then forced done through the radiator tubes where it is cooled by the passing air and returned back to the lower half of the engine.

Air cooled systems require small fins around the cylinders to dissipate the heat generated by the combustion process that takes place while the engine is running. These air cooling systems are more common in the motor cycle industry and stationary engines.

In the water/ fluid systems there are a number of components needed within the system to ensure that it works to its full potential. These are –

  • Radiator
  • Radiator pressure cap
  • Radiator fans
  • Expansion tank
  • Thermostat
  • Water Pump
  • Coolant
  • Coolant Hoses

The Radiator is designed for heat dissipation and usually is made of either brass or aluminium structure with thin flattened tubes surrounded with attached ribbing to dissipate the heat generated from the coolant as it passes through the tubes for this purpose. In older vehicles the tanks were on the top and bottom of the radiator and generally made or a copper core with brass tanks, but in more recent times radiators are generally now made of aluminium with plastic tanks on the side and the coolant passes the unit horizontally. The advantages of this style of Radiator is the cost of manufacturing the Component is reduced and also the use of plastic compounds to help prevent corrosion from affecting the condition of the radiator. Another advantage is the ability to integrate a cooling core inside one of the tanks to cool the transmission fluid.

The Radiator Pressure Cap is there to relieve any possible excess pressure in the system as the cooling liquid heats up and expands. In later systems this then escapes into the expansion tank whereas the engine cools off the liquid then returns to the radiator allowing for expansion and a cooling system that is always full. N This type of cap is different than a pressure cap only that allows the coolant to escape under pressure and heat but won’t allow the coolant to return to the cooling system, this is indicative of older systems in the mid-1950s to 1980.

As explained above the Expansion Tank is there to store over pressurised and heated coolant until the engine has cooled down and then lets the coolant return to the cooling system.

Radiator fans are essential to the cooling system as they force or draw air passed the radiator tubes and ribbed to intensify the amount of cooling capacity from the outside atmosphere. Traditionally in the middle of the century all fans were engine driven by the crank shaft and vee belt, as time has passed we now have electric fans and either thermostatically controlled or more recently computer controlled by sensors in the engine.

The Thermostat is a device that opens to allow coolant to pass through at a given temperature. All motors have a thermostat to control engine temperature usually constructed of a heat sensitive material such as copper with a bi metal configuration that is manufactured to a given specification and temperature to not operate until the engine has developed enough heat to the open the thermostat gradually to provide a consistent temperature in the engine.

The Water Pump is usually an integral part of the engine and driven by the crankshaft by a vee belt pulley. This obviously is a pump that forces coolant through the engine normally from the bottom of the block up passed the pistons into the head and through the radiator to be cooled again before repeating the process. In more recent times we have aftermarket electric water pumps of which Australia is one of the market leader within the industry. Some manufacturers are adopting the same reasoning and using electric pumps with the advantages or reducing fuel consumption and a more consistent cooling flow with in the whole system.

Coolant in today’s industry is an important factor. Gone are the days when water needed to be distilled and have some form of corrosion inhibitor and a little colour to keep the engine happy. Coolant today must be able to with stand temperatures well below freezing and not boil at temperatures well above water boiling point. Coolant today is a mixture of ethylene glycol (antifreeze) and water with the recommended amount being a fifty percent ratio.

Coolant Hoses are designed with the sole purpose to carry the Coolant from the Radiator through to the engine. There will be several Coolant Hoses on an engine which will carry the Coolant through to different components such as the heater core inside of the car, Automatic Transmission Coolers and of course the Radiator itself.

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