(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE - STANDARD PROCEDURE - DRAINING
COOLING SYSTEM).
(2) Refill cooling system with clean water (Refer to
7 - COOLING/ENGINE - STANDARD PROCEDURE
- FILLING COOLING SYSTEM).
(3) Run engine with pressure cap installed until
upper radiator hose is warm.
(4) Stop engine and drain water from system. If
water is dirty, fill, run and drain system again until
water runs clear.
(5) After system is clean, fill cooling system with
the proper mixture of Mopart Antifreeze/Coolant and
distilled water (Refer to 7 - COOLING/ENGINE -
STANDARD PROCEDURE - FILLING COOLING
SYSTEM).
COOLANT
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. 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, CONTACT
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
protection and less boiling 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. Then coolant 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 requires special corrosion protection.
Mopart Antifreeze/Coolant, 5 Year/100,000 Mile For-
mula (MS-9769), or the equivalent ethylene glycol base
coolant with hybrid organic corrosion inhibitors called
HOAT, (Hybrid Organic Additive Technology) is recom-
mended. This coolant offers the best engine cooling
without corrosion when mixed with 50% Ethylene Gly-
col and 50% distilled water to obtain a freeze point of
-37°C (-35°F). If it loses color or becomes contaminated,
drain, flush, and replace with fresh properly mixed cool-
ant solution.
The green coolant MUST NOT BE MIXED with
the orange or magenta coolants. When replacing cool-
ant the complete system flush must be performed
before using the replacement coolant.
CAUTION: MoparT Antifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Doing so
will reduce the corrosion protection and may result
in premature water pump seal failure. If non-HOAT
coolant is introduced into the cooling system in an
emergency, it should be replaced with the specified
coolant as soon as possible.
DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION TESTING
Coolant concentration should be checked when any
additional coolant was added to 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
(-35°F) to -46°C (-50°F). The use of a hydrometer or a
refractometer can be used to test coolant concentra-
tion.
A hydrometer will test the amount of glycol in a
mixture by measuring the specific gravity of the mix-
ture. The higher the concentration of ethylene glycol,
the larger the number of balls that will float, and
higher the freeze protection (up to a maximum of
70% by volume glycol).
A refractometer will test the amount of glycol in a
coolant mixture by measuring the amount a beam of
light bends as it passes through the fluid.
Some coolant manufactures use other types of gly-
cols into their coolant formulations. Propylene glycol
is the most common new coolant. However, propylene
glycol based coolants do not provide the same freez-
ing protection and corrosion protection and is only
recommended for limited usage. Refer to appropriate
Technical Service Bulletin(s) regarding use of propy-
lene glycol based coolants.
CAUTION: Do not mix types of coolant—corrosion
protection will be severely reduced.
ZB ENGINE 7 - 15
ENGINE (Continued)
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