Cooling System: Description and Operation

General Description





The Cooling System is a pressurized type, where the water pump, which is cambelt driven, forces the circulation of the coolant through the cylinder block and head. The thermostat regulates the flow of coolant between the radiator and the bypass circuit. The heater is part of the bypass circuit. The throttle body pre-heat is a separate circuit which is not regulated by the thermostat. An oil cooler may be fitted as part of this circuit.

Water Pump





The water pump is centrifugal type and is driven by timing belt.

Thermostat





The thermostat is a bypass type and is a wax pellet type with a air hole (1).

Radiator





The radiator is a flow type with corrugated fins.

Antifreeze Solution
^ Relation between Mixing ratio and Freezing temperature of the engine coolant varies with the ratio of antifreeze solution in water. Proper mixing ratio can be determined by to the chart. Supplemental inhibitors or additives claiming to increase cooling capability that have not been specifically approved by Isuzu are not recommended for addition to the cooling system.





^ Calculating mixing ratio

Note: Antifreeze solution + Water = Total cooling system capacity.





^ Total Cooling System Capacity
7.2 Lit (1.90 US gal)

^ Mixing ratio
Check the specific gravity of engine coolant in the cooling system temperature ranges from 0° C to 50° C using a suction type hydrometer, then determine the density of the engine coolant by to the table.