Cooling Systems

Cooling Systems

About the engine cooling systems:

• The engine cooling system is designed not only to cool the engine but also to not over cool the engine. There is two types of engine cooling systems - (Air Cooling & Liquid Cooling)
• In automotive engines the hot air is drawn down through the radiator & cooled to a warm operating temperature then passed back through the engine.
• Coolant is what is pumped through the engine & radiator, Coolant/ Liquid being water mixed with antifreeze.
• Antifreeze is usually Ethylene Glycol or Propylene Glycol mixed with a small amount of Corrosion Inhibitor.

 Construction:

• The radiator has multiple parts that help the cool the engine.

Radiator cap

Coolant Expanding - When the coolant rises it pushes against the lower seal, it press's against the Pressure spring, which then the lower seal begins to rise letting the coolant past & dumped into the overflow bottle through the reservoir.

• Coolant Contracting - Is a smaller version of coolant expanding. When the radiator is running low on coolant it sucks through to the area where the vacuum valve is, once pressure has built up from the coolant. The vacuum spring then opens up the vacuum valve allowing the coolant to pass through.
• Filler neck - Is what the radiator cap twists on to.

Radiator Fins/ Core of the Radiator:

• The core of the radiator is were all the cooling of the coolant happens.
• The coolant passes through the tubes & the heat from the coolant is passed through to the fins & then evaporates to the air.
• Having more tubes in the radiator will create better cooling efficiency
• After the coolant passes through the radiator it then gets pushed through the engine & keeps the engine at a good operating temp

Pressure Testing The Cooling System

Remove the radiator cap & replace with the pressure tester cap.
make sure everything is connected properly.












Once connected then start pumping away until you can't pump no more.

Before doing any of the above we need to check for any leaks on the radiator & hoses.
The longer you leave this the better results.

Antifreeze Hydrometer - To check that the coolant in the radiator is right. At the green mark is good.

Thermostat

What is a thermostat:

The thermostat opens and closes to regulate the temperature within the engine. When the coolant/ water gets hot from the engine warming up, the wax pallet starts to melt allowing the rod (that is sealed in a rubber diaphragm which is then coated with the wax) to move opening up the thermostat valve. Once the valve has opened then the coolant/water is allowed through to begin to cool the engine down, when the engine has been bought back down to the right temperature it then close's.

The thermostat close's only by the cooled water running through thermostat & the wax begins to harden.

The thermostat is located within the thermostat housing, attached to the thermostat housing is the upper radiator hose, Thermo switch & the heater hose. There is a gasket that seals the housing together and prevents any leaks from happening.