NOTE:
Ethylene glycol-based antifreeze and propylene
glycol-based antifreeze should never be mixed.
Cooling System
COOLANT TYPE -
Your cooling system should always be
sufficiently charged with an adequate mixture of antifreeze and
water, regardless of the climate, in order to maintain a broad
operating temperature range. Your cooling system has been
factory-charged with an ethylene glycol-based antifreeze.
63
FIG 7.07
40%
-23ºC -10ºF
50%
-23ºC -34ºF
60%
-23ºC -65ºF
Ethylene Glycol
FIG 7.06
CHECKING CONCENTRATION -
The radiator cap is
located toward the rear of the engine compartment (fig. 7.05).
Never remove a cap from a hot engine. Always allow the engine
to cool before servicing cooling system.
A 50/50 antifreeze/water mixture is a conservative mixture
which allows good protection against both overheating and
freezing. If a stronger antifreeze mixture is required, be sure not
to exceed the engine manufacturer’s guidelines for antifreeze
mixing. The table in figure 7.07 gives a few examples of
ethylene glycol antifreeze/water mixture protection values.
Consult the engine manufacturer’s handbook for further
information.
Concentration should be checked every 500 hours or at the
beginning of each winter, whichever comes first. It should be
checked using a refractometer; “floating ball”-type density
testers or hydrometers are not accurate enough for use with
heavy duty diesel cooling systems.
FIG 7.05
VII.
SERVICE AND MAINTENANCE
Summary of Contents for STS12
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