7-23
TMS800E SERVICE MANUAL POWER TRAIN
Published 01-29-2014, Control # 496-00
WATER COOLING SYSTEM
Description
The cooling system consists of the radiator, coolant recovery
tank, engine cooling circuit, and the connecting hoses
(Figure 7-14). Cooling system capacity is approximately
49.2 l (52 qt). The temperature is controlled by a 83°C
(181°F) thermostat located between the top of the engine
and the top of the radiator.
The water pump is located on the right side of the engine and
is belt driven by the crankshaft pulley. Coolant enters the
pump from the bottom inlet hose or bypass hose. Coolant
flows from the water pump to the cylinder block, cylinder
head, and into the thermostat housing. If the thermostat is
closed the coolant enters the bypass hose and flows back to
the water pump. If the thermostat is open, the bypass hose is
blocked and most of the coolant flows back to the radiator.
At all times, the antifreeze/coolant should be properly
inhibited against corrosion, It is recommended that 50/50
fully formulated antifreeze/coolant be used at all times.
The radiator assembly consists of the engine water cooler,
and shroud.
A sight gauge is installed on the side of the surge tank to
visually check coolant level. A coolant level sensor is also
located in the surge tank. Coolant level high/low signals are
supplied to the engine ECM.
The crane is equipped with cab hot water heaters. Hot water
is supplied by the engine coolant system through electric
operated shutoff valves to each heater. The hot water to the
superstructure heater also passes through a strainer and a
two port water swivel. The strainer is a cleanable type and is
located on the right side of the carrier frame at the front
corner of hydraulic reservoir. Refer to Lubrication, page 9-1
for service of the strainer.
Maintenance
General
The cooling system includes the radiator, coolant recovery
tank, thermostat, the fan, and water pump. Radiator hoses
are also included in this group.
The cooling system is often neglected because the effects or
damage that result from an improperly maintained cooling
system usually occur gradually. The cooling system needs to
be maintained with the same attention as other systems.
The circulation of water through the cooling system relies
entirely upon the water pump. The water pump draws water
from the radiator and forces it through the water jacket and
cylinder head. There it accumulates heat and flows to the top
radiator tank. Then the water flows down through the radiator
core and is cooled by air from the fan. This process of
removing heat from water as it circulates holds the engine to
its efficient operating temperature.
The following paragraphs point out several facts about
cooling system components, the effects of cooling system
neglect, and procedures to be followed for cooling system
maintenance.
Effects Of Cooling System Neglect
Whenever an engine does not perform at top efficiency, a
neglected cooling system may be at fault even though the
engine part directly responsible is not a part of the cooling
system. Most of these problems can be traced to
overheating; however, an engine that is running too cold can
be just as troublesome.
Overheating
An engine that is overheating may lead to troubles such as
the following:
• Low power.
• Burned valves.
• Pinging or knocking.
• Excessive fuel consumption.
• Poor lubrication - increased engine wear.
• Sticking valves.
• Short injector life.
• Engine hot spots.
• Need for higher grade fuel.
Overcooling
An engine that is overcooled can lead to the following:
• Excessive fuel consumption.
• Sludge formation in crankcase.
• Corrosive acids formed in crankcase.
• Excessive fuel deposits in the exhaust system.
Antifreeze/Coolant
Fill the system with a 50/50 blended, fully formulated
extended life antifreeze/coolant at all times. Fully formulated
coolants resist sentimentation and degradation, thus
allowing longer replacement intervals. Refer to Lubrication,
page 9-1. This antifreeze/coolant is intended to provide
protection for a minimum of one (1) year in a properly
maintained cooling system. It provides protection against
freeze-up down to -36.6°C (-34°F) and boil-over up to
129.4°C (265°F) using a 15 psi pressure cap.
Reference Only
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