Changing Coolant
Draining Instructions
!
WARNING
NOTICE
Allow engine to cool before removing pressure
cap. Sudden loss of pressure could cause hot
coolant to boil and discharge violently. After en-
gine has cooled, turn cap 1/4 turn to allow any
pressure to escape slowly, then push down and
turn cap all the way off.
For information and procedures on draining
the seawater cooling system of Seawater
Cooled (Raw-water) Cooled Models, refer to
SECTION 6A. For information and procedures
on draining the Seawater Section of Closed
Cooling (Coolant) Models refer to SECTION
1B. For cold weather or extended storage, re-
fer to SECTION 1B.
IMPORTANT: A wire should be inserted into drain
holes to ensure that foreign material is not ob-
structing the drain holes. On some models with
two piece petcock, removal of petcock may be re-
quired so that wire can be inserted completely
into drain hole.
Closed Cooling Section
IMPORTANT: Engine must be as level as possible
to ensure complete draining of cooling system.
Closed cooling section of closed cooling system
should be kept filled year-round with recommended
coolant solution. Do not drain closed cooling section
forstorage,asthiswillpromoterustingofinternalsur-
faces. If engine will be exposed to freezing tempera-
tures, make sure that closed cooling section is filled
with an ethylene glycol antifreeze and water solution,
mixed to manufacturer’s recommended proportions,
to protect engine to lowest temperature to which it will
be exposed. If necessary, change coolant.
IMPORTANT: Closed cooling section must be
kept filled year round with recommended cool-
ant.Ifenginewillbeexposedtofreezingtempera-
tures, make sure closed cooling section is filled
with an ethylene glycol antifreeze and water solu-
tion properly mixed to protect engine to lowest
temperature to which it will be exposed.
IMPORTANT: Do not use Propylene Glycol Anti-
freeze in the closed cooling section of the
engine.
Coolant Recommendations
The following draining instructions apply to all en-
gines equipped with closed cooling. The location of
petcocks that require opening and hoses that require
removal are represented on the following pages for
the individual engines.
!
CAUTION
Alcohol or Methanol base antifreeze or plain wa-
ter are not recommended for use in fresh water
section of cooling system at any time.
IMPORTANT: Observe precautions previously
outlined before proceeding.
It is recommended that the coolant section of closed
cooling system be filled with 50/50 mixture of ethy-
lene glycol antifreeze and water. In areas where the
possibility of freezing DOES NOT exist, it is permissi-
ble to use solution of rust inhibitor and water (mixed
to manufacturer’s recommendations).
1.
2.
Remove pressure cap from coolant tank.
Drain coolant from locations as shown for your
model and engine. (Refer to the appropriate dia-
gram on the following “Draining Diagrams”
pages.)
3.
4.
After coolant has drained completely, reinstall
petcocks and hoses. Tighten clamps and pet-
cocks securely.
Change Intervals
Drain and flush coolant from the closed cooling sys-
tem at least every two years or whenever exhaust
gases have entered the system.
Remove coolant recovery bottle from mounting
bracket and pour out coolant.
5.
6.
Clean system as outlined in “Cleaning System.”
Fill system as outlined in “Filling Closed Cooling
Section.”
Index
6B-10 - 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