LINK-TRACK-LH 9G8736 - Caterpillar

Water pump inlet pipe (13) is connected to the expansion tank outlet. Coolant from the pump (12) flows through the piping to oil cooler (11). On D399 Engines, a portion of the coolant from the piping is directed into cylinder block (10). The flow from the oil cooler is to flywheel housing (9).
FLOW OF COOLANT (SCHEMATIC)
1-Aftercooler. 2-Elbow. 3-Exhaust manifold. 4-Cylinder head. 5-Temperature regulator housing. 6-Outlet pipe. 7-Expansion tank. 8-Bypass line. 9-Flywheel housing. 10-Cylinder block. 11-Oil cooler. 12-Water pump. 13-Inlet pipe. 14-Keel cooler.The flywheel housing has two separate passages. The upper passage carries the flow of coolant to the junction housing, at the left side of the flywheel housing. From the upper connection on the junction housing, part of the flow is directed through the pipe to the front core of the aftercooler (1). The crossover pipe, on the right side of the aftercooler, directs the flow through the rear core. Coolant then flows through the pipe connected to the lower connection on the junction housing where it joins with the bypassed coolant from the flywheel housing upper passage.Coolant flows back across the flywheel housing through the lower passage where the flow is divided, an equal part going to each bank of cylinders of the cylinder block.On engines with an attachment, such as a marine gear where an oil cooler is used, an adapter is mounted on the left of the flywheel housing. Part of the coolant is directed to the oil cooler from the adapter. This coolant passes through the attachment oil cooler and joins the flow of coolant in the lower passage of the flywheel housing.In the lower passage of the flywheel housing the flow of coolant is divided to each bank of the cylinder block (10) where it circulates upward around the cylinder liners, through the cylinder block to the cylinder heads (4).The coolant flows from the cylinder heads, through the elbows (2) to the exhaust manifold shields (3). The coolant circulates completely through the exhaust manifold shields forward to the temperature regulator housings (5) located at the front of each of the exhaust manifolds.
FLOW OF COOLANT (D399 Illustrated)
1-Aftercooler. 2-Elbow. 3-Exhaust manifold shields. 4-Cylinder head. 5-Temperature regulator housing. 6-Outlet pipe. 7-Expansion tank. 9-Flywheel housing. 10-Cylinder block. 11-Oil cooler. 12-Water pump. 13-Inlet pipe.Regulators, positioned in each housing, control the flow of coolant. With the regulators in the closed position, the coolant passes through a bypass line (8) to the water pump.When coolant has reached operating temperature, the regulators open. The coolant flows through the outlet pipe (6) to the keel cooler (14). The coolant then passes to the expansion tank (7) and on to the pump through the inlet pipe (13).Overheating
If difficulty is experienced with the engine overheating, check the following possible causes:1. Coolant Level. Insufficient coolant in cooling system. If the coolant level has been allowed to fall so low that the coolant is no longer properly circulating, the engine should be stopped immediately and allowed to cool before adding coolant. If there is still good