User Manual

RENR9968-02 21
Systems Operation Section
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Illustration 17
(2) Water temperature regulator housing
(4) Bypass hose
(9) Water pump
(10) O utlet to the radiator
(11) Inlet from the radiator
Two water temperature regulators control the
direction of c oo lant flow. When the coolant
temperature is below the normal operating
temperature, the water temperature regulators are
closed. The coolant is directed through bypass hose
(4) and into the top inlet of the water pump. When the
coolant te mperature reac he s the normal operating
temperature, the water temperature regulators open.
When the water temperature regulators are open, the
bypass is closed. Most of the coolant goes through
the outlet to the radiator for cooling. The remainder
flows through bypass hose (4) and into the water
pump.
Note: The water temperature regulators are an
important part of the cooling system. The water
temperature regulators divide coolant flow between
the radiator and the bypass hose in order to maintain
the normal operating temperature. If the water
temperature regulators are not installed in the
system, there is no mechanical control, and most of
the coolant will travel the path of least resis tance
through the bypass hose. This will cause the engine
to overheat in hot weather and the engine will not
reach normal operating temperature in cold weather.
Coolant Conditioner (If Equipped)
Some conditions of operation can cause pitting. This
pitting is caused by corrosion or by cavitation erosion.
A corrosion inhibitor is a chemical that provides
a reduction in pitting. The addition of a corrosion
inhibitor can keep this type of damage to a minimum.
The coo lant conditioner elemen t is a spin-on element
that is similar to the fuel filter and to the oil filter
elements. The coolant conditioner element attaches
to the coolant conditioner base that is mounted on
the front of the engine. Coolant flows from the water
pump to the coolant conditioner base and back to the
cylinder block. Coolant constantly flows through the
coolant conditioner element when the valves are in
the OPEN position.
The element has a specificamountofinhibitorfor
acceptable cooling syste m protection. As the coolant
flows through the element, the corrosion inhibitor
goes into the solution. The corrosion inhibitor is a dry
solution, so the inhibitor diss olves. T he corro sion
inhibitor then mixes to the correct c oncentration.
Two basic types of elements are used for the
cooling system. The two elements are the precharge
elements and the m aintenance elements. Each
type of element has a specific use. The elements
must be used correctly in order to get the necessary
concentration for cooling system protection. T he
elements also contain a filter. The coolant conditioner
elements should remai n in the system after the
conditioner material h a s dissolved.
The precharge element contains more than the
normal amount of inhibitor. The precharge element is
used w hen a system is first filled with new coola nt.
This element must add enough inhibitor in order to
bring the comp lete cooling syste m up to the correct
concentration .
The m aintenance elements have a normal amount
of inhibitor. The maintenance elements are installed
at the first change interval. A sufficient amount of
inhibitor is provided by the maintenance elements
in order to maintain the corrosion protection at an
acceptable lev el. Afte r the first change interval,
only maintenance elements are installed. In order
to provide the coo ling system with protection ,
maintenan ce elements are installed at specific
intervals.