 | |
| Illustration 1 | g01071916 |
992G Wheel Loader (S/N: 7HR) or 854G Wheel Dozer (S/N: 1JW) Cooling System | |
 | |
| Illustration 2 | g01070023 |
992G Wheel Loader (S/N: ADZAZX) or 854G Wheel Dozer (S/N: AMPA4W) Cooling System | |
The water pump draws coolant directly from the radiator. For the 992G Wheel Loader (S/N: 7HR) or the 854G Wheel Dozer (S/N: 1JW), the coolant flow from the pump is divided into two directions. Coolant is pumped through the engine oil cooler and the transmission oil cooler. Then, the coolant is pumped through the block of the engine. The coolant enters the cylinder block at the right rear cylinder. The coolant flows to both sides of the block through distribution manifolds. The distribution manifolds are connected to the water jacket of all the cylinders. The main distribution manifold is located just above the main bearing oil gallery. The remainder of the coolant from the water pump flows to the aftercooler before entering the cylinder block at the rear center of the engine.
For the 992G Wheel Loader (S/N: ADZAZX) or the 854G Wheel Dozer (S/N: AMPA4W), the water pump draws coolant directly from the radiator. Coolant is pumped through the engine oil cooler and the transmission oil cooler. Then, the coolant is pumped through the block of the engine. The coolant enters the cylinder block at the right rear cylinder. The distribution manifolds are connected to the water jacket of all the cylinders. The main distribution manifold is located just above the main bearing oil gallery. The water pump does not flow into two directions. The coolant that flows to the aftercooler is supplied by a separate water pump. This pump is the auxiliary water pump. Refer to the Section "Separate Circuit Aftercooler" for the separate aftercooler cooling system.
For the engine, the coolant flows upward through the cylinder water jacket. The coolant flows around the cylinder liners from the bottom to the top. Near the top of the cylinder liners, the water jacket is smaller. This is the area that has the hottest temperature. This shelf (smaller area) causes the coolant to flow faster for better liner cooling. Coolant from the top of the liners flows into the cylinder head. The coolant circulates around the parts that have the hottest temperature. Coolant flows to the top of each cylinder head. The coolant flows out of the cylinder head through an elbow into a water manifold. Then, the coolant flows through the manifold to the regulator housing.
For the 992G Wheel Loader (S/N: 7HR) or the 854G Wheel Dozer (S/N: 1JW), the water temperature regulator housing has an upper section and a lower flow section. The housing has four water temperature regulators. The sensing bulbs of the four water temperature regulators are in the lower section of the housing. These regulators normally block the flow of coolant back to the radiator and coolant is diverted through the bypass line to the inlet of water pump. As the temperature of the coolant increases, the water temperature regulators start to open and coolant flow to the bypass line is restricted. Some coolant is sent through the outlets to the source for coolant. Also, coolant flows from the upper section of the water temperature regulator housing to bearing housing for turbocharger. The coolant is then returned to the radiator.
For the 992G Wheel Loader (S/N: ADZAZX) or the 854G Wheel Dozer (S/N: AMPA4W), the water temperature regulator housing has two sections. The sections are divided by the water temperature regulators. These regulators normally block the flow of coolant to the radiator and coolant is diverted through the bypass line to the inlet of water pump. As the temperature of the coolant increases, the water temperature regulator starts to open. Then, coolant that is flowing to the bypass line is restricted. Coolant flows out of the regulator housing to the radiator.
Separate Circuit Aftercooler
 | |
| Illustration 3 | g01071438 |
Separate Circuit Aftercooler (1) Aftercooler. (2) Auxiliary water pump. (3) Inlet for the auxiliary water pump. | |
 | |
| Illustration 4 | g01071443 |
(1) Aftercooler. | |
For the 992G Wheel Loader (S/N: ADZAZX) or 854G Wheel Dozer (S/N: AMPA4W), the machine has a separate aftercooler. In the separate aftercooler system, coolant flows to the auxiliary water pump from the radiator. The auxiliary water pump sends coolant through a tube and into the aftercooler. The coolant flows through the aftercooler into a tube that allows coolant flow back to the radiator.
Radiator
 | |
| Illustration 5 | g01071434 |
Radiator Group (4) Hydraulic oil cooler. (5) Steering oil cooler. (6) Axle oil cooler. (7) Air conditioning condenser. | |
The radiator is the source of coolant for the cooling system. The radiator is made up of the following three sections. radiator top tank, radiator bottom tank and radiator core assembly.
The radiator top tank is separate for the radiator. The tank is used in order to fill the cooling system. The tank has one section for the cooling system and another section for the separate circuit aftercooler.
The radiator bottom tank is divided into two sections. The rear section accepts the return coolant from the water regulator housing and the aftercooler cooling system. The front section is connected to the inlet of the water pump.
The radiator core assembly is made up of two paths with a connection between the paths at the top of each core. As the coolant is returned to the radiator, the coolant flows into the rear section of the bottom tank. The coolant flows up the core through the rear three tube rows. As the coolant gets to the top of the core, the coolant flows through the crossover tank. Then, the coolant flows through the three front tube rows to the front section of the bottom tank.
As the coolant flows through the radiator cores in both directions and the air is pulled around the radiator core, the temperature of the coolant will be reduced.
Also, the radiator assembly consists of the refrigerant condenser, the hydraulic oil cooler, the steering oil cooler, and the axle oil cooler.
Reference: For additional information about the refrigerant condenser, refer to the Service Manual module Systems Operation, SENR5664, "Air Conditioning and Heating R-134a All Caterpillar Machines ".
Reference: For additional information about cooling the hydraulic system, refer to the Service Manual module Systems Operation, SENR1369 or RENR2126, "Hydraulic Fan System".
Reference: For additional information about cooling the steering system, refer to the Service Manual module Systems Operation, SENR1349, "General Information".
Reference: For additional information about the axle oil cooler, refer to the Service Manual module Systems Operation, SENR1346, "Axle Oil Cooler".