Figure 4. - Radiator Top Tank Used With Continuous
Deaeration Cooling System
When the cooling system is filled through the upper portion of
the tank, coolant enters the main cooling system at the water
pump and fills the radiator core and the engine from the
bottom, forcing air out the vents.
The basic design of the radiator top tank, used with the
continuous deaeration cooling system, can be seen in Figure
3. The tank piping can be seen in Figure 2. These
illustrations are not for a particular installation, but only a
On some IH chassis, the radiator does not have a two section
top tank. But, the chassis still has a continuous deaeration
cooling system. On such chassis, the upper section of the
radiator top tank is replaced with a remote mounted surge
tank, with external housing, that duplicates the function of the
vent tube and the coolant make-up line.
ENGINE WATER JACKET
The water jacket permits coolant to be circulated around the
cylinder walls, combustion chambers and valve assemblies.
Some of the coolant passages are small and can become
clogged If the cooling system does not receive the proper
Close inspection should be given to the following areas:
These are sometimes mistakenly termed "freeze plugs".
The plugs are present due to engine block casting methods
and not to protect against expansion from freezing.
Core plugs that show signs of leaking or rusting through
should be replaced. Refer to respective Engine Manual for
core plug replacement.
The drain plugs located in the water. jacket should receive
seasonal care and be kept free of rust and scale.
Must be in good condition to prevent both internal and external
leaks. If there are external leaks around gaskets, there may
also be internal leaks into the engine.
Proper tightening of the head bolts with a torque wrench is
essential for preventing leaks around the head gasket.
The water pump circulates the coolant through the cooling
system. It should be checked carefully for leaks and proper
lubrication. If leaking or in bad condition, it should be rebuilt or
replaced promptly. For water pump rebuild, refer to
respective Engine Manual.
The fan should be checked for loose or bent blades. A loose
blade could work free during operation and cause damage. A
bent blade will reduce the fans efficiency.
Thermostats provide a means of retarding or restricting the
circulation of coolant during engine warm-up. An inoperative
thermostat can cause engine overheating and a subsequent
loss of coolant. Thermostats can be tested by submerging in
hot water and noting the opening and closing temperature.
Use an accurate high temperature thermometer for making
this test. Refer to Engine Manual for proper opening and
HOSES AND CLAMPS
The only coolants which are recommended for use in IH
cooling systems are those which contain an ethylene glycol
base. Other base coolants may damage rubber hoses,
especially those made of silicone rubber. Type of rubber used
can usually be determined by color. Silicone hoses are made
in "COLOR" while other rubber hoses are "BLACK". If
coolants used are not of ethylene glycol base, this may affect
your engine warranty.
RECOMMENDED FOR USE WITH IH ENGINES. THESE
INTERNAL SEALS AND COOLANT HOSES AND CREATE A
POTENTIAL FIRE HAZARD DUE TO LOWER FLASH
POINTS THAN ETHYLENE GLYCOL TYPE ANTI-FREEZE.
Hoses and clamps should be checked regularly as they are
often the source of hidden trouble. Hoses may appear in good
condition on the outside but the inside may be partially
deteriorated. If there are any doubts about