Checking Coolant Level - Mercury MerCruiser D2.8L D-Tronic Service Manual

SERVICE MANUAL NUMBER 22

Checking Coolant Level

Alcohol or methanol base antifreeze or plain water are not recommended for use
in cooling system at any time.
Before starting engine each day, check to ensure that coolant is visible in coolant recovery
bottle.
Do NOT remove coolant pressure cap when the engine is hot - coolant may dis-
charge violently, causing severe burns. Let the engine cool before removing the
pressure cap.
If the coolant should get extremely low and the engine very hot, let the engine cool
for approximately 15 minutes before adding coolant; then, with the engine operat-
ing, add coolant slowly. Adding cold coolant to a hot engine may crack the cylinder
head or crankcase. Never use only water in the closed coolant section.
If coolant is not visible, check coolant (fresh water) section of cooling system, including
coolant recovery system, for leaks and repair as necessary. Refill coolant section with
required coolant solution.
If coolant is visible, start engine and operate until it reaches normal operating
temperature, then recheck coolant level in coolant recovery bottle. Coolant level MUST BE
between the Add and Full marks (on front of bottle). If level is low, remove fill cap from
coolant recovery bottle and add needed amount of required coolant. If frequent additions
of coolant are required, check closed cooling section for leaks.
Occasionally, check to ensure that coolant recovery system is functioning properly by
removing pressure cap from heat exchanger and checking the coolant level. After engine
has cooled down, turn pressure cap 1/4 turn to allow any pressure to escape slowly,
then push down and turn cap all-the-way off. Coolant level should be up to bottom of heat
exchanger filler neck. If low, inspect entire closed cooling coolant (fresh water) section
(especially coolant recovery system) for leaks and repair, as necessary.
IMPORTANT: When reinstalling pressure cap, tighten it until it contacts locking tabs
on filler neck.
90-860074-1 FEBRUARY 2002
CAUTION
WARNING
CAUTION
CLOSED COOLING SYSTEM
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