Chrysler RAM TRUCK 2500 1994 Service Manual page 48

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LUBRICATION AND MAINTENANCE 0 - 23
ENGINE COOLING SYSTEM
WARNINGS AND PRECAUTIONS
WARNING: A N T I F R E E Z E IS AN E T H Y L E N E G L Y C O L
B A S E C O O L A N T AND IS HARMFUL IF SWAL­
LOWED OR INHALED. IF S W A L L O W E D , DRINK
TWO G L A S S E S O F WATER AND INDUCE VOMIT­
ING. IF INHALED, MOVE TO F R E S H AIR A R E A .
S E E K MEDICAL ATTENTION IMMEDIATELY. DO NOT
S T O R E IN O P E N OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY A F T E R
COMING IN CONTACT WITH E T H Y L E N E G L Y C O L .
K E E P OUT O F R E A C H O F C H I L D R E N .
D I S P O S E O F G L Y C O L B A S E C O O L A N T P R O P ­
ERLY, CONTACT YOUR D E A L E R OR G O V E R N M E N T
A G E N C Y FOR LOCATION O F C O L L E C T I O N C E N T E R
IN YOUR A R E A .
DO NOT O P E N A COOLING S Y S T E M WHEN T H E
ENGINE IS AT RUNNING T E M P E R A T U R E , P E R ­
SONAL INJURY CAN RESULT.
AVOID RADIATOR COOLING FAN WHEN ENGINE
COMPARTMENT R E L A T E D S E R V I C E IS P E R ­
FORMED, P E R S O N A L INJURY CAN RESULT.
CAUTION: Do not use straight antifreeze a s engine
coolant, inadequate engine running temperatures
can result.
Do not operate vehicle without proper concentra­
tion of recommended ethylene glycol coolant, high
running temperatures and cooling system corrosion
can result.
The engine cooling system will develop internal
pressure of 97 to 123 kPa (14 to 18 psi) at normal op­
erating temperature. Allow the vehicle approximately
one half hour to cool off before opening the cooling
system. As an indicator of pressure, squeeze the up­
per radiator hose between index finger and thumb. I f
it collapses with little effort the system would have
low internal pressure and should be safe to open to
the first safety notch of the radiator cap. Refer to
Group 7, Cooling System.
COOLING SYSTEM INSPECTION
Coolant level should be inspected when other en­
gine compartment service is performed or when cool­
ant leak is suspected. Coolant recovery tank level
should read between the M I N and MAX marks, lo­
cated on the side of recovery tank, when the engine
is at normal operating temperature. Normal coolant
level maintenance does not require the removal of ra­
diator cap. Cooling system freeze protection should
be tested at the onset of the winter season or every
12 months. Service is required i f coolant is low, con­
taminated, rusty or freeze protection is inadequate.
To properly test cooling system, see Group 7, Cooling
System.
The cooling system factory fill is a mixture of 50%
Glycol based antifreeze and 50% water. Using a suit­
able hydrometer, measure antifreeze concentration in
the radiator when the engine is cool. I f the cooling
system has recently been serviced, allow coolant to
circulate for at least 20 minutes before taking hy­
drometer reading. Properly mixed coolant will protect
the cooling system to -37°C (-35°F). I f the freeze pro­
tection is above -28°C (-20°F), drain enough coolant
from the cooling system to allow room to add anti­
freeze to achieve adequate protection. A mix table on
the coolant container indicates the amount of anti­
freeze required to winterize the cooling system based
on the capacity, see Capacity Chart i n General Infor­
mation section of this group.
SELECTING ANTIFREEZE
Chrysler Corporation recommends Mopar Anti­
freeze/Summer Coolant, or equivalent be used to win­
terize and protect cooling system.
RADIATOR CAP
The radiator cap must be secure to provide proper
pressure release and coolant recovery. Inspect and
test radiator cap when cooling system service is per­
formed or when problem is suspected.
COOLING SYSTEM SERVICE
The cooling system should be drained, flushed and
filled with the proper coolant mixture at the inter­
vals described i n the Lubrication and Maintenance
Schedules. Refer to General Information section of
this group. For proper service instructions see Group
7, Cooling System.
ENGINE AIR CLEANER
The engine air filter should be serviced only when
the Filter Minder™ on the air cleaner lid indicates
restricted air flow (Fig. 5). Refer to Group 25, Emis­
sion Control Systems for proper service procedures.
EMISSION CONTROL SYSTEM
Inspect all emission control components and hoses
when other under hood service is performed. Refer to
emission system Vacuum Hose Label located on the
inside of the hood i n the engine compartment and
Group 25, Emission Control Systems fof proper ser­
vice procedures.
BATTERY
Inspect battery tray, hold down and terminal con­
nections when other under hood service is performed.
For proper diagnostic procedures refer to Group 8A,