International VT 365 Service Manual page 42

38
The cooling system keeps the engine within a
designated temperature range.
The centrifugal water pump (hub and impeller) is
mounted in the pump housing of the front cover. The
water pump has a built in reservoir to catch small
amounts of coolant that may seep past the seal.
CAUTION: The water pump impeller may be
damaged if dropped or hit by a hard object.
Front cover housing flow
The water pump draws coolant from the radiator
through inlet of the front cover housing. Coolant flows
from the water pump through three passages in the
front cover.
• Two passages (left and right) direct coolant into
the crankcase (front to rear) to cool the cylinder
walls and the cylinder heads.
• The third passage directs coolant through a
passage in the crankcase to the oil cooler cover.
NOTE: If an oil cooler seal is damaged, weep holes in
the oil filter base allow coolant to seep from the cooler
cover.
Coolant returns to the water pump through three
passages in the front cover.
• Two passages (left and right) from the crankcase
direct coolant to the front cover.
• A third passage directs coolant from the intake
manifold to the front cover.
Return coolant is directed to the thermostat in the front
cover.
• If the thermostat is open, coolant flows to the
radiator.
• If the thermostat is closed, coolant returns to the
water pump through a bypass passage in the front
cover, because the radiator outlet is blocked.
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
ENGINE SYSTEMS
As the engine reaches operating temperatures, the
thermostat opens and directs coolant to the radiator.
This also restricts the bypass opening.
Crankcase and cylinder head flow
Coolant flows through passages in the front cover
to the left and right sides of the crankcase. Coolant
flows through the front of both sides of the crankcase,
evenly distributing coolant around the cylinders, and
exits the rear of the crankcase flowing up to the
cylinder heads.
Coolant flows from the rear of the cylinder heads to
the front of the cylinder heads, exits down a passage
in the crankcase, and returns to the front cover.
Oil cooler and EGR cooler flow
The front cover directs coolant to a passage in the
crankcase. Coolant flows from the crankcase to the
front of the oil cooler cover. The oil cooler and the oil
filter base direct coolant to the front of the oil cooler.
Coolant flows through the oil cooler from the front to
rear and exits through the EGR cooler supply port.
Coolant flows from the rear of the EGR cooler to the
front returning to the front cover though a passage in
the intake manifold.
•
•
NOTE: Earlier engines have a single line from the
air compressor to the deaeration tank. Later engines
have two lines. One from the intake and one from the
air compressor that intersect one line to the deaeration
tank.
EGES295-2
Follow all warnings, cautions, and notes.
© 2006 International Truck and Engine Corporation
The deaeration port is on top of the intake
manifold.
For engines equipped with an air compressor
the deaeration point is at the air compressor and
intake manifold.