Fiat Kobelco EX355 Tier2, Technical Manual

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EX355 W5-5-1
ENGINE COOLING
SERVICE PRECAUTION
• Be sure to use the correct fastener in the proper
location. If a used fastener is replaced with a new
one, the new fastener must be identical to the
previous one.
• Some fasteners must always be replaced with new
ones following removal. These fasteners are speci-
fied in this Manual.
• Some fasteners require thread locker or thread
sealant. These fasteners are specified in this
Manual.
• Supplemental fastener coatings (paint, grease, or
corrosion inhibitor) affect fastener torque and
clamping force. They may damage the fastener. Do
not use them unless specifically called for.
• Tighten all fasteners to the specified torque. If there
is a tightening sequence, follow it exactly.
GENERAL DESCRIPTION
Coolant Flow
The engine cooling system consists of the radiator,
the surge tank, the water pump, the cooling fan, and
the thermostats.
When the engine and coolant are cold, the thermostat
with jiggle valve is completely closed. The water
pump circulates the coolant through the radiator
by-pass directly back to the cylinder body (coolant
does not pass through the radiator). This provides a
rapid increase in coolant temperature and smooth
engine operation.
When the coolant temperature reaches 82 °C
(180 °F), the thermostat begins to open. A gradually
increasing amount of coolant passes through the
radiator before returning to the cylinder block.
When the coolant temperature reaches 95 °C
(203 °F), the thermostat is fully open. All coolant now
passes through the radiator before returning to the
cylinder block. Effective engine cooling is ensured.
SM7286
Radiator
Reserve
tank
Water outlet pipe
Thermostat
Water jacket, Cylinder head
Water
jacket,
Cylinder
body
Water drain Oil cooler
Water
pump