Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual - part 1699

ENGINE COOLING  6B-1

SECTION 6B

ENGINE COOLING

CONTENTS

PAGE

General Description ....................................................................................................... 6B- 2

Service Precaution ......................................................................................................... 6B- 3

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- 8

Thermostat ...................................................................................................................... 6B- 9

Removal...................................................................................................................... 6B- 9

Inspection................................................................................................................... 6B- 9

Installation.................................................................................................................. 6B- 9

Fan clutch with Cooling Fan.......................................................................................... 6B- 9

Inspection and Repair ............................................................................................... 6B- 9

Radiator ........................................................................................................................... 6B-11

Radiator and Associated Parts ................................................................................. 6B-11

Removal...................................................................................................................... 6B-11

Inspection................................................................................................................... 6B-12

Installation.................................................................................................................. 6B-13

Main Data and Specifications........................................................................................ 6B-13

Special Service Tool....................................................................................................... 6B-14

6B-2  ENGINE COOLING

General Description

Legend

1 Water Pump
2 Thermostat
3 Radiator
4 Reserve Tank

5 Coolant Distributor
6 Cylinder Block and Head
7 Throttle Body
8 Heater

The Cooling System is a pressurized type, where the water
pump, which is cambelt driven, forces the circulation of
the coolant through the cylinder block and head. The
thermostat regulates the flow of coolant between the
radiator and the bypass circuit. The heater is part of the
bypass circuit. The throttle body pre-heat is a separate
circuit which is not regulated by the thermostat. An oil
cooler may be fitted as part of this circuit.

ENGINE COOLING  6B-3

Service Precaution

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.

Water pump

The water pump is centrifugal type and is driven by timing belt.

Thermostat

The thermostat is a bypass type and is a wax pellet type with a
air hole.

Radiator

The radiator is a flow type with corrugated fins.

6B-4  ENGINE COOLING

Antifreeze Solution

• Relation  between  Mixing  ratio  and  Freezing  temperature  of

the engine coolant varies with the ratio of antifreeze 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.

• Calculating mixing ratio
Mixing ratio

=

Antifreeze solution (Lit/gal.)

Antifreeze solution (Lit/gal.) + Water (Lit/gal.)

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

• Total Cooling System Capacity
5.7Lit

• 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%.