Owner`s manual

2008 KNIGHT
CHASSIS INFORMATION — 10
213
Good-Quality Water:
Good quality water is important for cooling
system performance. Excessive levels of
calcium and magnesium contribute to scaling
problems, and excessive levels of chlorides and
sulfates cause cooling system corrosion.
Testing the Coolant:
A refractometer must be used to measure the
freezing point of the coolant accurately. DO
NOT use a oating ball hydrometer. Using
oating ball hydrometers can give an incorrect
reading.
Coolant System Sealing Additives:
DO NOT use sealing additives in the cooling
system. The use of sealing additives will:
Build up in coolant low-ow areas.
Plug the radiator and oil cooler.
Possibly damage the water pump seal.
Cooling System Soluble Oils:
DO NOT use soluble oils in the cooling
system. The use of soluble oils will:
Corrode brass and copper.
Damage heat transfer surfaces.
Damage seals and hoses.
Check the coolant level before each trip,
refueling, and when checking the oil level.
Coolant freeze point is checked at every oil
change interval or as specied by the engine
manufacture. Coolant drain and ush intervals
are specied by the engine manufacturer. Refer
to the OEM engine manual for more information
on service maintenance intervals.
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INFORMATION
Refer to the engine OEM manual for
details on engine coolant maintenance.
Coolant Types:
Use a low-silicate antifreeze that meets
ASTM4985 (GM6038M specication)
criteria.
Fully formulated coolant MUST meet
ASTM D-6210/D-6211.
Recommendations include using either
a 50/50 mixture of good quality water
and fully formulated antifreeze or fully
formulated coolant.
NOTE
For detailed information on engine
coolants for Cummins engines, refer to
Cummins Coolant Requirements and
Maintenance Bulletin 3666132.
Engine Coolant Reservoir:
The engine coolant reservoir is connected
to the radiator by a hose. Coolant heats and
expands as the motorhome is driven. Coolant
displaced by expansion, overows from the
radiator into the reservoir. Coolant contracts as
it cools and is drawn back in the radiator by a
vacuum. Thus, the radiator is lled to capacity
with coolant at all times resulting in increased
cooling efciency. The coolant level should be
at, or slightly above, the appropriate mark on the
reservoir tank when the system is cold.
The reservoir is marked MIN (cold
check)/MAX (hot check), or the reservoir
has upper (hot check) and lower (cold check)
sight windows. Maintain coolant between the
appropriate reservoir indicators.
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CAUTION
DO NOT remove the reservoir cap while
the engine is running or if the engine is
hot. Cap removal can result in severe
burns and damage to the engine cooling
system.
NOTE
Be sure to replace cap
after adding fliud.
Coolant Levels:
Check coolant level before
each trip, when refueling,
and when checking the oil
level.
A low coolant alarm will sound and a
low coolant indication will appear on the
instrument panel if coolant level drops
below acceptable levels in the reservoir.
Stop the motorhome and inspect the
coolant level before continued operation.
Coolant level should remain between
the MIN and MAX indicators on the
reservoir when the cooling system is
properly lled.
Supplemental Coolant Additive (SCA):
SCA is required to protect the cylinder
liner/sleeve from cavitation erosion. Cavitation
erosion is caused by minute air pockets that
collect on the cylinder liner. The air pockets will
pop (implode) during engine operation. Over
time this can erode a hole through the cylinder
liner. Supplemental coolant additives inhibit
formation of the air pockets. The SCA content of
the coolant is checked with Litmus paper.
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Coolant Reservoir
cap is rated at 16 lbs.