Seawater Flow Thru Exhaust
Manifolds
2. Start engine and run AT IDLE. Add coolant
solution to heat exchanger, as required, to
maintain coolant level at filler neck. After engine
has reached normal operating temperature (ther-
mostat 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.
!
CAUTION
Alcohol or Methanol base antifreeze or plain wa-
ter, are not recommended for use in coolant sec-
tion of Closed Cooling System at any time.
3.
Remove cap from coolant recovery reservoir and
fill to “Full” mark with coolant solution. Reinstall
cap.
It is recommended that coolant section of Closed
Cooling System be filled with a 50/50 mixture of ethy-
lene glycol antifreeze and pure, soft water. Antifreeze
MUST BE used regardless of whether freezing tem-
peratures are or are not expected to provide ade-
quate corrosion protection. In areas where ethylene
glycol antifreeze is not available and the possibility of
freezing DOES NOT exist, it is permissible to use a
solution of rust inhibitor and pure, soft water (mixed
to manufacturer’s recommendations).
4. Lift recovery bottle and plastic tubing above heat
exchanger filler neck. Allow coolant to flow down
through tubing to purge air through filler neck
fitting.
5.
Install pressure cap on heat exchanger.
6. With engine still running, check hose connec-
tions, fittings and gaskets for leaks. Also 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.
NOTE: Coolant section capacity is approximately 4
U.S. Gallons (15 L).
1.
Fill coolant section of Closed Cooling System
with coolant mixture as follows:
!
WARNING
a. Open bleeder valve on thermostat housing.
Allow engine to cool down before removing pres-
sure 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 al-
low any pressure to escape slowly, then, push
down and turn cap all-the-way off.
b. Fill with coolant mixture through heat ex-
changer fill neck until coolant appears at
bleeder valve opening.
c. Close bleeder valve securely.
d. Continue filling until coolant level is into filler
neck and begins to flow into coolant recovery
bottle plastic tubing.
7.
Recheck coolant level after first open-throttle
boat test and add coolant, if necessary.
!
CAUTION
8. Maintain coolant level in coolant recovery reser-
voir between “Add” and “Full” marks with engine
at normal operating temperature.
DO NOT operate engine without water flowing
thru seawater pickup pump, as pump impeller
may be damaged and subsequent overheating
damage to engine or stern drive unit may result.
Coolant section of Closed Cooling System should be
kept filled year around with recommended coolant
solution. DO NOT drain coolant, fresh water section,
forstorage,asthiswillpromoterustingofinternalsur-
faces. If engine will be exposed to freezing tempera-
tures, make sure that coolant section is filled with
ethylene glycol antifreeze and water solution, mixed
to manufacturer’s recommended proportion, to pro-
tect engine to lowest temperature to which it will be
exposed.
•
Front of engine should be higher than rear to
purge trapped air out of the system during initial
filling. This will minimize the possibility of air be-
ing trapped in the closed cooling section which
can cause engine to overheat.
IMPORTANT: This closed cooling system flows
coolant at a high rate. Higher idle speeds in-
crease dispersion of trapped air into system
making it more difficult to purge trapped air. Op-
erate at idle during filling and air purging when
specified.
Index
6B-16 - CLOSED COOLING SYSTEMS
90-823224--2 796
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
Thank you