CAP-SEAL 3E4051 - Caterpillar

This engine has a pressure type cooling system that is equipped with an expansion tank (2) and a recovery bottle (1).
Illustration 1 g01040648
(1) Recovery Bottle with a vented cap
(2) Expansion Tank with a pressure relief capA 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 (1) 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
Illustration 2 g03325167
SCAC circuit flow schematic (thermostat closed)
(3) Tank
(4) CAC
(5) Heat exchanger
(6) FC
(7) Water pump
(8) Thermostat housing
(9) Vent location
(10) Vent flow (full time)
(11) Vent flow (checked)
Illustration 3 g03325498
SCAC circuit flow schematic (thermostat open)
(3) Tank
(4) CAC
(5) Heat exchanger
(6) FC
(7) Water pump
(8) Thermostat housing
(9) Vent location
(10) Vent flow (full time)
(11) Vent flow (checked)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 pump is used when sea water enters the system. This type of pump will resist the corrosive action of the coolant that passes through the pump.
A cast iron pump is used when the coolant is pure and noncorrosive.Raw water is drawn in through the inlet of the auxiliary water pump. The raw water will flow through the fuel cooler before the auxiliary water pump inlet if the engine is equipped with the optional fuel cooler. The raw water is forced out of the pump and into the aftercooler. The raw water flows through the aftercooler and exits at the end of the aftercooler. The raw water then travels through the marine gear cooler(if equipped), the heat exchanger, and the exhaust elbow (if equipped). The raw water is then discharged.Coolant Flow Circuit
Illustration 4 g03325505
Jacket water circuit flow (thermostat open)
(3) Tank
(5) Heat exchanger
(7) Water pump
(8) Thermostat housing
(9) Vent location
(10) Vent line (full time)
(11) Vent line (checked)
(12) Deaerator
(13) Exhaust manifold
(14) Oil cooler
(15) Turbocharger
Illustration 5 g03325541
Jacket water circuit flow (thermostat closed)
(3) Tank
(5) Heat exchanger
(7) Water pump
(8) Thermostat housing
(9) Vent location
(10) Vent line (full time)
(11) Vent line (checked)
(12) Deaerator
(13) Exhaust manifold
(14) Oil cooler
(15) TurbochargerThe water pump is located on the side 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. The coolant exits the