General information and precautions

Cooling, heating and ventilation systems / General information and precautions

General information
1 The cooling system is of pressurised type, including a pump, an aluminium crossflow radiator, electric cooling fan, and a thermostat. The system functions as follows.

Cold coolant is pumped around the cylinder block, head passages, expansion tank, inlet manifold and heater matrix by the coolant pump. After cooling the cylinder bores, combustion surfaces and valve seats, the coolant is returned to the water pump via the metal tube at the rear of the engine. With the engine cold, the thermostat is initially closed and there is no circulation through the radiator.

2 When the coolant reaches a predetermined temperature, the thermostat opens and the coolant passes through to the radiator. As the coolant circulates through the radiator it is cooled by the inrush of air when the car is in forward motion. Airflow is supplemented by the action of the electric cooling fan when necessary. From the bottom of the radiator the coolant passes through the thermostat to the coolant pump and the cycle is repeated. In this system the thermostat is located in the return line to the coolant pump.

3 The electric cooling fan mounted on the rear of the radiator is controlled by a thermostatic switch. At a predetermined coolant temperature the switch actuates the fan.

Precautions
Warning: Do not attempt to remove the expansion tank filler cap or disturb any part of the cooling system while the engine is hot, as there is a high risk of scalding. If the expansion tank filler cap must be removed before the engine and radiator have fully cooled (even though this is not recommended) the pressure in the cooling system must first be relieved. Cover the cap with a thick layer of cloth, to avoid scalding, and slowly unscrew the filler cap until a hissing sound can be heard. When the hissing has stopped, indicating that the pressure has reduced, slowly unscrew the filler cap until it can be removed; if more hissing sounds are heard, wait until they have stopped before unscrewing the cap completely. At all times keep well away from the filler cap opening. Warning: Do not allow
antifreeze to come into contact with skin or pain ted surfaces of the vehicle. Rinse off spills immediately with plenty of water. Never leave antifreeze in an open container or in a puddle in the driveway or on the garage floor. Children and pets are attracted by its sweet smell. Antifreeze can be fatal if ingested.

Warning: If the engine is hot, the electric cooling fan may start rotating even if the engine is not running, so be careful to keep hands, hair and loose clothing well clear when working in the engine compartment.