BOLT 6V5815 - Caterpillar

The coolant system contains the following components:
Header tank
Pressure cap for the header tank
Water pump
Drive pulley for the water pump
Water temperature regulator
Housing for the water temperature regulator
Coolant temperature switch
Heat exchanger (if equipped)
Sea water pump (if equipped)
Keel cooler (if equipped)On engines with a heat exchanger, the coolant flows from the bottom of the header tank to the heat exchanger. From the heat exchanger, the water flows to the water pump. The water pump is installed on the cylinder block above the timing case. The water pump is driven by a pulley. The crankshaft pulley turns a belt which drives the pulley of the water pump.The water pump forces the coolant to flow through the head and the engine block. When the engine is cold, the water temperature regulator is closed. Then, the coolant bypasses the heat exchanger and the coolant is recirculated through the engine. When the engine warms, the water temperature regulator begins to open. Then, the regulator allows some of the coolant to flow to the heat exchanger.The regulator opens fully when the engine reaches the normal operating temperature. When the regulator is fully open, the flow to the heat exchanger is maximum. Coolant flows continuously through the cylinder head and the top of the cylinder block. This coolant flows into the back of the water pump from the cylinder block. This coolant then mixes with the coolant that is pumped from the heat exchanger by the water pump.The water temperature regulator maintains the correct engine temperature by adjusting the direct flow of coolant to the heat exchanger. The coolant is cooled by the heat exchanger. Heat is removed from the coolant by the sea water. The sea water is pumped to the heat exchanger by an auxiliary water pump. The sea water is kept separate from the engine coolant inside the heat exchanger by metal tubes. The raw sea water is pumped from the heat exchanger to the exhaust elbow.This engine may utilize marine keel cooling. In this case, the auxiliary water pump and the heat exchanger are removed. These parts are replaced with a keel cooler that is in contact with the sea water. Marine keel cooling involves circulating the engine coolant through a keel cooler instead of a heat exchanger.The engine has a housing for the water temperature regulator. The housing is installed on the header tank.