Mercury MerCruiser MCM 454 Mag MPI Service Manual page 872

SERVICE MANUAL NUMBER 23
2. Start engine and run AT IDLE. Add coolant solution to heat exchanger, as required, to
3. Remove cap from coolant recovery reservoir and fill to "Full" mark with coolant solution.
4. Lift recovery bottle and plastic tubing above heat exchanger filler neck. Allow coolant
5. Install pressure cap on heat exchanger.
6. With engine still running, check hose connections, fittings and gaskets for leaks. Also
Allow engine to cool down before removing pressure cap. Sudden loss of pressure
could cause hot coolant to boil and discharge violently. After engine has cooled
down, turn cap 1/4-turn to allow any pressure to escape slowly, then push down and
turn cap all the way off.
7. Recheck coolant level after first boat test and add coolant, if necessary.
8. Maintain coolant level in coolant recovery reservoir between "Add" and "Full" marks with
Coolant section of Closed Cooling System should be kept filled year around with recom-
mended coolant solution. DO NOT drain coolant from fresh water section for storage, as this
will promote rusting of internal surfaces. If engine will be exposed to freezing temperatures,
make sure that coolant section is filled with Extended Life 5/100 Coolant and water solution,
mixed to manufacturer's recommended proportion, to protect engine to lowest temperature
to which it will be exposed.
Index
90-861326--1 MARCH 1999
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maintain coolant level at filler neck. After engine has reached normal operating tempera-
ture (thermostat is fully open), and coolant level remains constant, fill heat exchanger
until coolant level is into filler neck and begins to flow into coolant recovery bottle plastic
tubing.
Reinstall cap.
to flow down through tubing to purge air through filler neck fitting.
observe engine temperature gauge to make sure that engine operating temperature is
normal. If gauge indicates excessive temperature, stop engine immediately and
examine for cause.
engine at normal operating temperature.
CLOSED COOLED (FRESH WATER) MODELS
WARNING
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