Components of water cooling system
RADIATOR
The function of the radiator is to ensure close contact of the hot coolant coming out of the engine with outside air, so as to ensure high rates of heat transfer from the coolant to air. A radiator consists of an upper (or header) tank, core and the lower (or collector) tank. Besides, an overflow pipe in the header tank and drain pipe in the lower tank are provided. Hot coolant from the engine enters the radiator at the top and is cooled by the cross-flow of air, while flowing down the radiator. The coolant collects in the collector tank from where it is pumped to the engine for cooling. There are two basic types of radiator cores, viz., tubular type and cellular type. In the former, it is the coolant that flows through tubes and air passes around them, while in the cellular type the air passes through the tubes and coolant flows in the spaces in between them. Out of these, tubular type cores are the most commonly used which are further classified depending upon the shape of the fins around the tubes, which are meant to increase the area for heat transfer from coolant to the cooling air. Both the core tubes as well as the fins are made from thinnest possible material. Tubes are made from 0.1 mm to 0.3 mm sheet, whereas fins are made from about 0.1 mm thick material. The materials used for radiators should be resistant to corrosion, possess higher thermal conductivity and form easily, apart from having adequate
strength. Copper and yellow brass are the widely used materials for. radiators. Aluminium is also used from weight and cost considerations. Some late model radiators have plastic tanks with aluminium cores. The size of the radiator must be adequate to remove the heat which is approximately equal to the heat, energy utilized producing power in the engine. Alternatively, the radiator size is matched to the displacement volume of the engine. The air conditioned vehicle would require a large radiator due to extra heat load on account of the compressor. Besides, it is also ensured that maximum cooling is attained with minimum air resistance. Thus frontal area of the radiator is kept minimum, which may be achieved by making the core thicker and accommodating more core material into the same volume without increasing the air resistance. For heavy duty applications, radiators shutters are also sometimes used.
These are automatically controlled by means of the compressed air taken from the brake system. Shutter control mechanism is installed with the upper hose of the cooling system. Depending upon the coolant temperature coming from the engine, which itself depends upon the engine temperature, the shutter control mechanism causes the shutter to open or close. Thus, for example, the shutter remains closed during starting and it gradually opens up as the engine attains its working temperature, thus allowing the fresh air to come into contact with the radiator.
COOLINIG SYSTEM SERVICING
The cooling system must operate, be inspected, and be serviced as a system. Replacing one damaged part while leaving others dirty or clogged will not increase system efficiency. Service the entire system to ensure good results. Service involves both a visual inspection of the parts and connections and pressure testing. Pressure testing is used to detect internal or external leaks. The following is a list of places to check for a suspected leak in the cooling system. Although this is not a complete list, it does present the most common areas where a leak can occur.
External Leakage:
Radiator
Loose hose clamp
Hose
Faulty radiator cap
Dented radiator hose connector for the inlet or outlet hose
Heater connection
Water pump, through weep hole
Cracked or porous water pump housing & Heater core
Loose core hole plug in cylinder block
Cracked thermostat housing
Water temperature sending unit
Cylinder head bolts loose or tightened unevenly
Warped or cracked cylinder head
Heater control valve
Cracked cylinder block
Damaged gasket or dry gasket if engine has been stored
Coolant reservoir or hose
Internal Leakage:
Faulty head gasket
Cracked head
Cracked block
Transmission fluid cooler
RADIATOR
The function of the radiator is to ensure close contact of the hot coolant coming out of the engine with outside air, so as to ensure high rates of heat transfer from the coolant to air. A radiator consists of an upper (or header) tank, core and the lower (or collector) tank. Besides, an overflow pipe in the header tank and drain pipe in the lower tank are provided. Hot coolant from the engine enters the radiator at the top and is cooled by the cross-flow of air, while flowing down the radiator. The coolant collects in the collector tank from where it is pumped to the engine for cooling. There are two basic types of radiator cores, viz., tubular type and cellular type. In the former, it is the coolant that flows through tubes and air passes around them, while in the cellular type the air passes through the tubes and coolant flows in the spaces in between them. Out of these, tubular type cores are the most commonly used which are further classified depending upon the shape of the fins around the tubes, which are meant to increase the area for heat transfer from coolant to the cooling air. Both the core tubes as well as the fins are made from thinnest possible material. Tubes are made from 0.1 mm to 0.3 mm sheet, whereas fins are made from about 0.1 mm thick material. The materials used for radiators should be resistant to corrosion, possess higher thermal conductivity and form easily, apart from having adequate
strength. Copper and yellow brass are the widely used materials for. radiators. Aluminium is also used from weight and cost considerations. Some late model radiators have plastic tanks with aluminium cores. The size of the radiator must be adequate to remove the heat which is approximately equal to the heat, energy utilized producing power in the engine. Alternatively, the radiator size is matched to the displacement volume of the engine. The air conditioned vehicle would require a large radiator due to extra heat load on account of the compressor. Besides, it is also ensured that maximum cooling is attained with minimum air resistance. Thus frontal area of the radiator is kept minimum, which may be achieved by making the core thicker and accommodating more core material into the same volume without increasing the air resistance. For heavy duty applications, radiators shutters are also sometimes used.
These are automatically controlled by means of the compressed air taken from the brake system. Shutter control mechanism is installed with the upper hose of the cooling system. Depending upon the coolant temperature coming from the engine, which itself depends upon the engine temperature, the shutter control mechanism causes the shutter to open or close. Thus, for example, the shutter remains closed during starting and it gradually opens up as the engine attains its working temperature, thus allowing the fresh air to come into contact with the radiator.
COOLINIG SYSTEM SERVICING
The cooling system must operate, be inspected, and be serviced as a system. Replacing one damaged part while leaving others dirty or clogged will not increase system efficiency. Service the entire system to ensure good results. Service involves both a visual inspection of the parts and connections and pressure testing. Pressure testing is used to detect internal or external leaks. The following is a list of places to check for a suspected leak in the cooling system. Although this is not a complete list, it does present the most common areas where a leak can occur.
External Leakage:
Radiator
Loose hose clamp
Hose
Faulty radiator cap
Dented radiator hose connector for the inlet or outlet hose
Heater connection
Water pump, through weep hole
Cracked or porous water pump housing & Heater core
Loose core hole plug in cylinder block
Cracked thermostat housing
Water temperature sending unit
Cylinder head bolts loose or tightened unevenly
Warped or cracked cylinder head
Heater control valve
Cracked cylinder block
Damaged gasket or dry gasket if engine has been stored
Coolant reservoir or hose
Internal Leakage:
Faulty head gasket
Cracked head
Cracked block
Transmission fluid cooler
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