Cooling system Cooling System The cooling system consists of: A. Radiator B. Recovery Bottle C. Fan D. Thermostat E. Water Pump F. Fan Belt
A B C D E
To ensure an even temperature within the engine, the cylinder head and cylinder walls of the engine are water-cooled. This water is in turn cooled in the radiator. The water is circulated from the radiator to the engine and back through the radiator by means of a water pump. Radiator The radiator consists of a cluster of hollow tubes enshrined into a number of fins and enclosed at both ends by a Top Tank and a bottom tank. Air sucked by Fan passes through the radiator fins thereby cooling the coolant flowing through radiator tubes. The fins should be kept clear of mud or dirt accumulation. Over heating may be caused by bent or clogged radiator fins. If the spaces between the radiator fins become clogged, clean them with compressed air or coolant blown from engine side. Radiator Cap A pressurized radiator cap is provided which is set at 9.9-psi (0.7 kg/cm2 ) pressure. This cap ensures better cooling and avoids loss of coolant due to evaporation. It also reduces corrosion in engine sleeve & crankcase; hence it is strongly recommended that the engine should not be run without radiator cap. Also ensure that rubber gasket is intact & perfectly sealing the system pressure. Recovery Bottle When the engine is in operation, certain amount of coolant passes out of the radiator overflow pipe. This coolant is not allowed to escape into the atmosphere and captured into a Recovery Bottle.When the engine is not operating and the coolant cools down,certain amount of coolant comes back into the radiator from Recovery Bottle. The Recovery Bottle thus helps to prevent loss of coolant Thermostat This device prevents coolant circulating through the radiator until the engine reaches its operating temperature. With the thermostat closed, the coolant circulates only through the engine block. It is important that if the thermostat is defective, do not attempt to repair it, replace with new. When installing a new thermostat, ensure the valve is facing upward. The thermostat operating temperature is 180°F.
F
When straightening bent fins be careful not to damage the tubes or to break the bond between the fins and tubes.
The cooling system operates under pressure. • It is dangerous to remove the radiator cap while the system is hot. • Always turn the cap slowly to the first stop,and allow pressure to escape before removing the cap completely.
Do not run the engine when the cooling system is empty, and do not add cold coolant or cold antifreeze solution if the engine is hot. The coolant level in surge tank should not fall below the MIN level mark.
Do not run the Engine without Thermostat Valve.
58 Model 25 25 4WD OPM/Sep-07
