Isuzu Trooper (1998-2002 year). Manual - part 256

ENGINE COOLING

6B–1

ENGINE

ENGINE COOLING

CONTENTS

Service Precaution

6B–1

. . . . . . . . . . . . . . . . . . . . . . 

General Description

6B–2

. . . . . . . . . . . . . . . . . . . . . 

Diagnosis

6B–5

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Draining and Refilling Cooling System

6B–6

. . . . . 

Water Pump

6B–7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Water Pump and Associated Parts

6B–7

. . . . . . . 

Removal

6B–7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection

6B–7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

6B–7

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Thermostat

6B–8

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Thermostat and Associated Parts

6B–8

. . . . . . . . 

Removal

6B–8

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection

6B–8

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

6B–8

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Radiator

6B–9

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Radiator and Associated Parts

6B–9

. . . . . . . . . . 

Removal

6B–9

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Inspection

6B–10

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

6B–11

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Drive Belt and Cooling Fan

6B–12

. . . . . . . . . . . . . . . 

Drive Belt and Associated Parts

6B–12

. . . . . . . . . 

Inspection

6B–12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Installation

6B–12

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Main Data and Specifications

6B–13

. . . . . . . . . . . . . 

Special Tool

6B–14

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Service Precaution

WARNING: IF SO EQUIPPED WITH A
SUPPLEMENTAL RESTRAINT SYSTEM (SRS),
REFER TO THE SRS COMPONENT AND WIRING
LOCATION VIEW IN ORDER TO DETERMINE
WHETHER YOU ARE PERFORMING SERVICE ON OR
NEAR THE SRS COMPONENTS OR THE SRS
WIRING. WHEN YOU ARE PERFORMING SERVICE
ON OR NEAR THE SRS COMPONENTS OR THE SRS
WIRING, REFER TO THE SRS SERVICE
INFORMATION. FAILURE TO FOLLOW WARNINGS
COULD RESULT IN POSSIBLE AIR BAG
DEPLOYMENT, PERSONAL INJURY, OR
OTHERWISE UNNEEDED SRS SYSTEM REPAIRS.

CAUTION: Always use the correct fastener in the
proper location. When you replace a fastener, use
ONLY the exact part number for that application.
ISUZU will call out those fasteners that require a
replacement after removal. ISUZU will also call out
the fasteners that require thread lockers or thread
sealant. UNLESS OTHERWISE SPECIFIED, do not
use supplemental coatings (Paints, greases, or other
corrosion inhibitors) on threaded fasteners or
fastener joint interfaces. Generally, such coatings
adversely affect the fastener torque and the joint
clamping force, and may damage the fastener. When
you install fasteners, use the correct tightening
sequence and specifications. Following these
instructions can help you avoid damage to parts and
systems.

SECTION

6B–2

ENGINE COOLING

General Description

030RW001

Legend

(1) Water Pump
(2) Thermostat
(3) Radiator
(4) Reserve Tank
(5) Cooling Fan
(6) Cylinder Block

(7) Cylinder Head
(8) Right Bank
(9) Throttle Body

(10) Cylinder Block

(11) Cylinder Head

(12) Left Bank
(13) Heater

The cooling system is a pressurized Engine Coolant (EC)
forced circulation type which consists of a water pump,
thermostat cooling fan, radiator and other components.
The automatic transmission fluid is cooled by the EC in
radiator.

Water Pump

The EC pump is a centrifugal impeller type and is driven
by a timing belt.

030RS001

ENGINE COOLING

6B–3

Thermostat

The thermostat is a wax pellet type with a air hole(1) and is
installed in the thermostat housing.

031RW002

Radiator

The radiator is a tube type with corrugated fins. In order to
raise the boiling point of the coolant, the radiator is fitted
with a cap in which the valve is operated at 88.2 

∼

 117.6

kPa (12.8 

∼

 17.0 psi) pressure. (No oil cooler provided for

M/T)

110RS001

Anti Freeze Solution

D

Relation between the mixing ratio and freezing
temperature of the EC varies with the ratio of
anti–freeze solution in water. Proper mixing ratio can
be determined by referring to the chart. Supplemental
inhibitors or additives claiming to increase cooling
capability that have not been specifically approved by
Isuzu are not recommended for addition to the cooling
system.

D

Calculating mixing ratio

F06RW005

6B–4

ENGINE COOLING

NOTE: Antifreeze solution + Water = Total cooling
system capacity.

D

Total Cooling System Capacity

D

M/T 8.8Lit (2.32Us gal)

D

A/T 8.4Lit (2.22Us gal)

B06RW002

D

Mixing ratio

Check the specific gravity of engine coolant in the
cooling system temperature ranges from 0

°

C to 50

°

C

using a suction type hydrometer, then determine the
density of the engine coolant by referring to the table.

NOTE:

1. Even in the areas where the atmospheric

temperature is higher than 0

°

C, be sure not to use

antifreeze solution at a mixing ratio lower than 20% so
that the inside of the engine may not be corroded.

2. If antifreeze solution is used at a mixing ratio higher

than 60%, the specific heat of the coolant falls and the
engine may be overheated. Moreover, antifreeze
performance drop and the coolant may be frozen.
The density of the solution must be adjusted as
occasion calls.

Antifreeze solution lower than 20% may not have
sufficient anticorrosive performance, and therefore,
please never fail to adjust as occasion demands within
the range of 20% to 60%.

B06RW003