GUARD AS-TRACK GUIDE 1531624 - Caterpillar

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Schematic of a heat exchanger cooled separate circuit aftercooled system
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Schematic of a keel cooled separate circuit aftercooled system
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(32) Expansion Tank with a pressure relief cap (33) Recovery Bottle with a vented capThis engine has a pressure type cooling system that is equipped with an expansion tank (32) and a recovery bottle (33) .A pressure type cooling system offers two advantages:
The cooling system can operate safely at a temperature that is higher than the normal boiling point of water.
The cooling system prevents cavitation in the water pump.Cavitation is the sudden formation of low-pressure bubbles by mechanical forces in liquids. The formation of air or steam pockets is more difficult within a pressure type cooling system.The shunt line prevents cavitation by the water pump. The shunt line provides additional flow of coolant to the water pump inlet.The recovery bottle (33) provides space for expansion of the coolant volume while the engine is running. Also, the recovery bottle provides space for expansion during the warm-up cycle. The recovery bottle also provides a means for checking the coolant level.Raw Water Circuit
In many instances, a separate cooling source is used to supply coolant to the aftercooler. The coolant supply can be fresh water, or the coolant supply can be sea water. Because of the possible unknown composition of the cooling water, a special pump is needed to move the coolant through the system. Two types of pumps are available for use in the raw water circuit.
A bronze impeller and/or a rubber impeller pump is used to flow sea water through the cooling system. These types of pumps will resist the corrosive action of the coolant that passes through the pump. Raw water is drawn in through the inlet of the auxiliary water pump . The raw water is forced out of the pump and into the aftercooler. The raw water is then discharged or passed through the gear oil cooler (if equipped) and then discharged.Coolant Flow Circuit
Raw water pump is located on the left front corner of the cylinder block. The water pump is gear-driven from the crankshaft.Coolant from the heat exchanger is pulled into the inlet of the water pump by impeller rotation. After the water exits the water pump, the water is dispersed to the following components: engine oil cooler , cylinder head, cylinder block and turbochargers. Coolant also flows from each cylinder head and each turbocharger to each of the exhaust risers and from the exhaust risers to the exhaust manifolds. Next, the coolant flows through a deaerator in the rear frame of the heat exchanger in order to purge excess air from the coolant to the expansion tank. The coolant is then directed by the water temperature regulator either to the bypass back to the jacket water pump or to the heat exchanger to be cooled.Note: The water temperature regulator controls the direction of flow. When the coolant temperature is below the normal operating temperature, the water temperature regulator is closed. The coolant that is leaving