MOTOR AS 4W5122 - Caterpillar

Illustration 1 g00929651
Flow diagram of the cooling system
The coolant flows from the bottom of the radiator to the centrifugal water pump. The water pump assists in the flow of the coolant through the system. The water pump is installed on the front of the timing case. The water pump is gear-driven by the fuel injection pump gear.The water pump forces the coolant through a passage in the front of the timing case to the water jacket in the top left side of the cylinder block. The coolant continues to the rear of the cylinder block and some of the coolant passes into the oil cooler. The aluminum cover of the oil cooler covers the element. The element can have either five plates or seven plates. The oil cooler is located on the left side of the cylinder block with no external lines.The coolant flows around the element of the oil cooler to the rear of the cylinder block. The coolant then passes from the rear of the cylinder block and into the rear of the cylinder head.The coolant flows forward through the cylinder head and into the water temperature regulator housing. If the water temperature regulator is closed, the coolant goes directly through a bypass to the inlet side of the water pump. If the water temperature regulator is open, the bypass is closed and the coolant flows to the top of the radiator.