Mercury MERCRUISER Service Manual

Cooling System
Section 6C - Models with Closed Cooling
Table of Contents
Specifications.....................................................................6C-2
Heat Exchanger Assembly—Exploded View..................... 6C-3
Crossover for Closed Cooling—Exploded View................ 6C-4
Description.........................................................................6C-4
Meeting the Minimum Seawater Flow Specifications........ 6C-4
Bravo Models with Closed Cooling.............................6C-4
Installing the Y‑Fitting................................................. 6C-5
Installing the Seawater Supply Hose..........................6C-6
Through‑the‑Hull Seawater Pickup System.......................6C-6
Seawater Strainer.......................................................6C-7
Seawater Pickup.........................................................6C-7
Seacock......................................................................6C-8
Seawater Strainer.............................................................. 6C-9
Seawater Strainer Mounting Requirements................6C-9
Seawater Strainer Installation.....................................6C-9
Cleaning the Seawater Strainer, if Equipped............6C-10
Coolant............................................................................ 6C-10
Coolant Recommendations...................................... 6C-10
Maintaining Coolant Level........................................ 6C-11
Pressure Cap Maintenance and Testing......................... 6C-11
Testing the Closed‑Cooling System................................ 6C-12
Testing Coolant for Alkalinity.................................... 6C-12
Pressure Testing the System................................... 6C-12
Seawater Pressure Test........................................... 6C-13
Testing for a Cylinder Head Gasket Leak.................6C-14
Thermostat.......................................................................6C-14
Thermostat Removal................................................ 6C-14
Thermostat Testing...................................................6C-14
Thermostat Installation............................................. 6C-15
Changing Coolant............................................................ 6C-15
Closed‑Cooling Section............................................ 6C-15
Draining the Closed Cooling System........................6C-15
Cleaning the Cooling System................................... 6C-16
Filling the Cooling System........................................ 6C-16
Heat Exchanger Assembly.............................................. 6C-17
Testing—Internal Leaks............................................6C-17
Blockage...................................................................6C-17
Heat Exchanger Removal.........................................6C-17
Heat Exchanger Disassembly.................................. 6C-18
Cleaning and Inspection........................................... 6C-18
Heat Exchanger Repair............................................ 6C-18
Heat Exchanger Installation......................................6C-19
Models with Closed Cooling
90-8M0099748 eng DECEMBER 2015 © 2016 Mercury Marine Page 6C-1
6
C

Mercury MERCRUISER Specifications

General

Brand	Mercury
Model	MERCRUISER
Category	Engine
Language	English