Cooling System, External Cooling - Volvo Penta TAMD74A-A Operator's Manual

Cooling system, external cooling

Introduction
A cooling system with external cooling does not have a heat exchanger but is cooled by heat being transferred
via one or two external cooling circuits. A single circuit system serves all the components being cooled. A dual
circuit system has either two freshwater circuits or one freshwater circuit together with one seawater circuit. In
both cases, one of the circuits cools the engine and the other circuit cools the charge air cooler and the reverse
gear's oil cooler. A "seawater" pump (A) is not included on a one circuit cooling system.
Two circuits
One circuit
One or two
circuits
A
Coolant level. Check
WARNING! Never open the filler cap when the
engine is warm. Steam or hot fluid may spurt
out.
IMPORTANT! Check the coolant level on a cold
stationary engine.
Make sure the level ends up between the MIN and
MAX marks. If there are no marks, the coolant level
should be approx. 5 cm (2") below the top of the filler
cap (1). Fill if necessary with the same type of coolant
that is already in the system.
Maintenance: Freshwater system
1
Two circuits
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