Cleaning System
1. Remove seawater drain plug from bottom of heat
exchanger and allow water to drain. After water
has drained completely, coat threads of drain
plug with Quicksilver Perfect Seal and rein-
stall.
Closed Cooling Section
Closed cooling section of closed cooling system
should be cleaned at least once every two years or
whenever decreased cooling efficiency is experi-
enced.
A good grade automotive cooling system cleaning
solution may be used to remove rust, scale or other
foreign material. Always follow manufacturer’s in-
structions for the cleaner.
c
e
a
If closed cooling section is extremely dirty, a pressure
flushing device may be used to flush out remaining
deposits. Flushing should be done in direction oppo-
site normal coolant flow to allow water to get behind
deposits and force them out. Refer to instructions
which accompany flushing device for proper hookup
and flushing procedure.
d
b
72718
NOTICE
Typical V-8 Engine
For information and procedures for draining
and flushing Seawater Section of Closed
Cooling (Coolant) Models, refer to SECTION
1B. For cold weather or extended storage, re-
fer to SECTION 1B.
a - Bolt
b - End Cap
c - Sealing Washer
d - Gasket
e - Drain Plug
2.
Remove bolts which secure end plates to each
end of heat exchanger, then remove end plates,
seal washers and gaskets. Discard seal washers
and gaskets. Clean gasket material from end
plates and heat exchanger.
Seawater Section
Cooling efficiency of an engine with closed cooling is
greatly dependent upon heat transfer through the
tubes within the heat exchanger. During engine oper-
ation, contaminants within the seawater (such as
salt, silt, lime, etc.) collect on the inside of the tubes,
thus reducing heat transfer and greatly decreasing
heat exchanger efficiency. It is, therefore, recom-
mended that the seawater section of the heat ex-
changer be cleaned at least once every two years or
whenever decreased cooling efficiency is suspected,
as follows:
3.
4.
Clean water passages in heat exchanger by in-
serting a suitable size wire brush into each pas-
sage. Use compressed air to blow loose particles
out of water passages.
Apply Quicksilver Perfect Seal to both sides of
new end plate gaskets, then reinstall end plates,
using new gaskets and seal washers. (Be sure to
install seal washers between end plates and gas-
kets.) Torque end plate bolts to specifications.
IMPORTANT: It may be necessary to remove heat
exchanger on some models. If heat exchanger is
removed, be sure to refill closed cooling section
with coolant.
!
CAUTION
Avoid seawater pickup pump impeller damage.
DO NOT operate engine without water being
supplied to seawater pickup pump.
5.
With boat in the water and/or cooling water prop-
erly supplied to seawater pickup pump, start en-
gine and inspect for leaks.
Index
6B-14 - 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.
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