CHASSIS INFORMATION - 10
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CAY M A N 2 0 0 7
Coolant System Maintenance
Inspect other components of the cooling
system when performing maintenance. Have
an inspection performed of the surge tank cap
seal and have the cap pressure tested at each oil
change. The charge air cooler and radiator also
require inspection for cracks, broken welds,
secure mounting, and general cleanliness.
It may be necessary to clean the radiator
and external coolers more often under certain
conditions. Road debris and other contaminants
can block the radiator and cooler ns resulting
in reduced cooling system performance.
Blockage can vary depending on road, climate,
and regional conditions. Check the radiator and
external coolers weekly for blockage, and clean
as required.
Compressed air is recommended to clean the
radiator and external coolers. In the event that
road grime, oil, or inadequate cleaning with
compressed air is encountered, a high pressure
washer and degreaser may be used with caution
to avoid excess pressure that can bend the
radiator ns.
Refer to the OEM manual for detailed
maintenance and service procedures. These
services include: draining the engine coolant,
ushing/cleaning the cooling system, inspecting
the water pump standpipe, replacing the
thermostat, gasket and seal, and replacing the
coolant and SCA element.
Coolant Hoses:
Rotten, swollen and worn hoses, as well
as loose connections, are frequent causes of
coolant system problems. Overheating can be
caused by a collapsed hose or a clog caused by
rubber shedding from a rotton hose. Replace any
hose found to be cracked, swollen or damaged.
Connections should be inspected periodically
and hose clamps tightened.
INSPECTION:
Check all hoses, clamps, and fittings
for leaks due to cracking, softness, and
loose clamps/fittings. Look for signs
of fluid leaks, damaged end fittings,
ballooning, chafed, kinked, or crushed
hoses, and loose clamps and fittings.
Correct any deficiencies found.
Coolant Overheated:
If the engine is overheated, never pour cold
coolant into a hot engine. The sudden change
in temperature may crack the cylinder head or
block. If the engine is hot, ll slowly to prevent
rapid cooling and distortion of engine castings.
INSPECTION:
Inspect the radiator core and CAC for
dirt and debris build-up. Wash any
accumulations using high-pressure
water, being careful not to damage the
fins from excessive pressure. Grease
or oil build-up should be treated first
with a non-caustic degreaser to ensure a
thorough cleaning.
Coolant System - Thawing:
If the coolant system becomes frozen,
the motorhome must be towed. Place the
motorhome in a warm area until completely
thawed. If the engine is operated when the
cooling system is frozen it will result in
engine overheating due to insuf cient coolant
circulation. Once thawed, check engine, radiator
and related components for damage caused by
expansion of frozen coolant.
Radiator/Charge Air Cooler
The diesel engine uses compression to ignite
the fuel/air charge. To increase compression
inside the combustion chamber (resulting in
increased power output) a turbocharger is added
to the engine. The turbocharger is a paired
housing assembly with impellers inside each
housing connected by a common shaft. One
impeller is propelled by the engine exhaust,
which drives the other impeller. The function
of the other impeller is to increase compression
inside the combustion chamber by forcing air
into the intake manifold.
This process works well, however, the intake
air charge is heated two different ways: through
convection by the exhaust gases driving the
turbocharger and when air is compressed. This
negative effect inside the combustion chamber
results in lost power potential. Therefore, a
Charge Air Cooler (CAC) is installed to cool
the intake air before it enters the engine. The
CAC performs the same function as a radiator,
cooling air instead of liquid. Ambient air
passing through the CAC will cool the engine
intake air charge.
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