WARNING: ANTIFREEZE IS AN ETHYLENE-GLYCOL BASE COOLANT AND IS HARMFUL IF SWALLOWED OR
INHALED. IF SWALLOWED, DRINK TWO GLASSES OF WATER AND INDUCE VOMITING. IF INHALED, MOVE
TO FRESH AIR AREA. SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT STORE IN OPEN OR UNMARKED
CONTAINERS. WASH SKIN AND CLOTHING THOROUGHLY AFTER COMING IN CONTACT WITH ETHYLENE-
GLYCOL. KEEP OUT OF REACH OF CHILDREN. DISPOSE OF GLYCOL BASE COOLANT PROPERLY, CON-
TACT YOUR DEALER OR GOVERNMENT AGENCY FOR LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN THE ENGINE IS AT OPERATING TEMPERATURE OR HOT
UNDER PRESSURE, PERSONAL INJURY CAN RESULT. AVOID RADIATOR COOLING FAN WHEN ENGINE
COMPARTMENT RELATED SERVICE IS PERFORMED, PERSONAL INJURY CAN RESULT.

CAUTION: Use of Propylene-Glycol based coolants is not recommended, as they provide less freeze pro-
tection and less corrosion protection.

The cooling system is designed around the coolant. The coolant must accept heat from engine metal, in the cylinder
head area near the exhaust valves and engine block. The coolant then carries the heat to the radiator where the
tube/fin radiator can transfer the heat to the air.

The use of aluminum cylinder blocks, cylinder heads, and water pumps require special corrosion protection. Use
coolant approved to MB 325.0, such as Mopar part number 05066386AA, or an equivalent Extended Life Coolant
with the HOAT inhibitor system. This coolant offers the best engine cooling without corrosion when mixed with 50%
ethylene-glycol and 50% distilled water to obtain a freeze point of -37°C (-35°F). If it loses color or becomes con-
taminated, drain, flush, and replace with a fresh properly mixed coolant solution.

CAUTION: Mixing of coolants other than specified (non-HOAT or other HOAT), may result in decreased cor-
rosion protection, and engine damage could result. The subsequent engine damage may not be covered
under the new vehicle warranty.

COOLANT PERFORMANCE

The required ethylene-glycol (antifreeze) and water mixture depends upon the climate and the vehicle operating
conditions. The coolant performance of various mixtures follows:

Pure Water-Water can absorb more heat than a mixture of water and ethylene-glycol. This is for the purpose of
heat transfer only. Water also freezes at a higher temperature and allows corrosion.

100 percent Ethylene-Glycol-The corrosion inhibiting additives in ethylene-glycol need the presence of water to
dissolve. Without water, additives form deposits in the cooling system. These act as insulation causing the temper-
ature to rise to as high as 149°C (300°F). This temperature is hot enough to melt plastic and soften solder. The
increased engine operating temperature can result in engine detonation. In addition, 100 percent ethylene-glycol
freezes at -22°C (-8°F).

50/50 Ethylene-Glycol and Water-Is the recommended mixture, it provides protection against freezing to -37°C
(-34°F). The antifreeze concentration must always be a minimum of 44 percent, year-round in all climates. If the
percentage is lower, engine parts may be eroded by cavitation. Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which prevents freezing down to -67.7°C (-90°F). A higher percentage
will freeze at a warmer temperature. Also, a higher percentage of antifreeze can cause the engine to overheat
because the specific heat of antifreeze is lower than that of water.

CAUTION: Richer antifreeze mixtures cannot be measured with normal field equipment, and can cause prob-
lems associated with 100 percent ethylene-glycol.

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ENGINE

COOLANT SELECTION AND ADDITIVES

CAUTION: Do not use coolant additives that are claimed to improve engine cooling.

OPERATION

Coolant flows through the engine block absorbing the heat from the engine, then flows to the radiator where the
cooling fins in the radiator transfers the heat from the coolant to the atmosphere. During cold weather the antifreeze/
coolant prevents water present in the cooling system from freezing within temperatures indicated by mixture ratio of
coolant to water.

DIAGNOSIS AND TESTING

COOLANT CONCENTRATION

Coolant concentration should be checked when any additional coolant is added to the cooling system, or after a
coolant drain, flush and refill. The coolant mixture offers optimum engine cooling and protection against corrosion
when mixed to a freeze point of -37°C (-34°F) to -46°C (-50°F). The use of a hydrometer or a refractometer can be
used to test coolant concentration.

A hydrometer will test the amount of glycol in a mixture by measuring the specific gravity of the mixture. The higher
the concentration of antifreeze/coolant, the larger the number of balls that will float, and higher the freeze protection.

A Refractometer, Special Tool 8286, will test the amount of antifreeze/coolant in a coolant mixture by measuring the
amount a beam of light bends as it passes through the fluid.

ENGINE

7 - 21

CAUTION: Do not mix different types of coolant—corrosion protection will be severely reduced.

STANDARD PROCEDURE

DRAINING

WARNING: DO NOT REMOVE THE CYLINDER BLOCK DRAIN PLUGS OR LOOSEN THE RADIATOR DRAIN-
COCK WITH THE COOLING SYSTEM HOT AND UNDER PRESSURE. SERIOUS BURNS FROM COOLANT CAN
OCCUR.

1. DO NOT remove the pressure cap first. With the engine cold, raise and support the vehicle on a hoist and locate

the radiator draincock.

Note: Radiator draincock is located on the left/lower side of radiator facing to rear of vehicle.

2. Attach one end of a hose to the draincock (2). Put the other end into a clean container. Open draincock and

drain the coolant from the radiator. This will also empty the coolant recovery reservoir (1). When the tank is
empty, remove the pressure cap and continue draining the cooling system.

REFILLING

1. Tighten the radiator draincock and the cylinder block drain plug(s) (if removed).

CAUTION: Failure to purge air from the cooling system can result in an overheating condition and severe
engine damage.

2. Fill system using a 50/50 mixture of antifreeze/coolant and low mineral content water. Fill the coolant recovery

reservoir to service line and install pressure cap.

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ENGINE

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