Filling The Closed Cooling System - Mercury MerCruiser D2.8L D-Tronic Service Manual

SERVICE MANUAL NUMBER 22

Filling The Closed Cooling System

1. Remove pressure cap from heat exchanger and fill section with specified coolant until
coolant level is 25 mm (1 in.) below filler neck.
Avoid seawater pickup pump impeller damage and subsequent overheating dam-
age to sterndrive unit. DO NOT operate engine without water being supplied to sea-
water pickup pump.
2. With pressure cap off, start engine and operate at fast idle (1500-1800 rpm). Add
recommended coolant solution to heat exchanger, as required, to maintain coolant level
25 mm (1 in.) below filler neck.
3. After engine has reached normal operating temperature (thermostats are fully open),
and coolant level remains constant, fill heat exchanger to bottom of filler neck.
4. Observe engine temperature gauge to make sure that engine operating temperature is
normal.
IMPORTANT: If gauge indicates excessive temperature, stop engine immediately and
examine for cause.
5. Install pressure cap on heat exchanger.
6. Remove cap from coolant recovery reservoir. Fill to FULL mark with recommended
coolant solution. Reinstall cap.
7. With engine still operating, check hose connections, fittings and gaskets for leaks.
Repeat Step 4.
90-860074-1 FEBRUARY 2002
CAUTION
CLOSED COOLING SYSTEM
Page 6B-21