2007 ISUZU KB P190 engine

Engine Cooling – V6 Engine Page 6B1–26

10 Pressure test the cooling system. Refer to 3.7 Pressure Testing in this Section.
Engine

Refer to ‘
‘‘
‘
Environmental Issues ’
’’
’
in 3.1
Service Notes, before draining the coolant.
1 Drain the cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.

Always wear eye protection when working
with spring-type hose clamps. Failure to do
so may result in eye injury.
2 Remove the upper and lower radiator hoses from the coolant outlet housing and coolant inlet pipe connections. Refer to Figure 6B1 – 22.
3 Remove the thermostat housing from the rear of the engine block. Refer to 6A1 Engine Mechanical – V6..
4 Remove the thermostat from the thermostat housing and reinstall the housing to the rear of the intake manifold. Refer to 3.8 Thermostat in this Section.
5 Remove both heater hoses (1) and (2) from their connections at the heater pipe assembly, noting
which hose was connected to which connection.
Seal the heater pipe assembly connections by
looping the heater inlet connection to the outlet
connection using a suitable piece of hose and two
hose clamps.
6 Install a lead-away hose to the coolant inlet pipe connection and a length of suitable hose between
the coolant outlet housing connection and the
flushing equipment.
7 Connect and operate the flushing equipment as recommended by the manufacturer.
Figure 6B1 – 23
8 Continue flushing until the water from the lead-away hose runs clear.
9 Remove the coolant recovery reservoir, flush it out with clean water and install. Refer to 3.9 Coolant Recovery Reservoir in this Section.
10 Install the thermostat. Refer to 3.8 Thermostat in this Section.
11 Install all disconnected hoses, ensuring that they are correctly positioned and securely clamped.
12 Fill the cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.
13 Pressure-test the cooling system. Refer to 3.7 Pressure Testing in this Section.

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Engine Cooling – V6 Engine Page 6B1–27

Heater Hoses and Core

Refer to ‘
‘‘
‘
Environmental Issues ’
’’
’
in 3.1
Service Notes, before draining the coolant.
1 Drain the cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.

Always wear eye protection when working
with spring-type hose clamps. Failure to do
so may result in eye injury.
2 Remove both heater hoses (1) and (2) from their connections at the heater pipe assembly, noting
which hose was connected to which connection.
3 Direct the hose (1) that was connected to the heater pipe assembly’s front connection into a
suitable container.
4 Attach the hose (2) from the rear-most connection to the flushing gun.
5 Cycle the heater switch to ensure that the water valve is open.


Figure 6B1 – 24
6 Connect and operate the flushing equipment as recommended by the manufacturer.

Apply air pressure gradually and not in
excess of 130 kPa, otherwise heater core
damage will result.
7 Install all disconnected hoses, ensuring that they are correctly positioned and securely clamped.
8 Fill the cooling system. Refer to 3.3 Draining and Filling Cooling System in this Section.
9 Pressure test the cooling system. Refer to 3.7 Pressure Testing in this Section.

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ISUZU KB P190 2007

Engine Cooling – V6 Engine Page 6B1–28

3.5 Drive Belt Tension
An automatic tensioner assembly provides drive belt tension. The tensioner is an idler pulley mounted on a spring-loaded
arm that maintains the drive belt at the proper tension, without imposing undue loads on the various components.

Throughout its functional travel, the tensioner mechanism
will maintain correct belt tension, using a pulley (1) mounted
to a spring-loaded arm (2), which compensates for increases
in belt wear and stretch.
W hen the indicator pointer (3) on the tensioner has reached
minimum tension range (4), the tensioner has reached the
full extent of its travel and replacement of the belt (5) is
necessary.
The maximum tension range is shown at (6).
Drive belt tension can be checked using Tool No. BT3373-F.
Refer to 6A1 Engine Mechanical.
Figure 6B1 – 25

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Engine Cooling – V6 Engine Page 6B1–29

Inspect
The four views in Figure 6B1 – 26 show the various stages of drive belt wear, to assist in belt replacement decisions.
NOTE
Condition of the belt ribs can be better assessed
if the belt is wrapped over the coolant pump drive
pulley.

Figure 6B1 – 26
Legend
A New Belt: No cracks or c hunks.
B Moderately Used Belt: Few cra cks, with some wear on the ribs and in the grooves. Belt replacement not required.
C Severely Used Belt: Several cracks per 30 mm. S hould be replaced before chunking occurs
D Failed Belt: Separation of rib material from backing (chunking). Belt must be replaced immediately.

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Engine Cooling – V6 Engine Page 6B1–30

3.6 Coolant Hoses

Always wear protective safety glasses when
working with spring type hose clamps. Failure
to do so could result in eye injury.
Coolant hoses are installed as shown in the following illustrations, taking note that there are a number of variants,
depending on a specific vehicle specification.
Hose connections should be thoroughly cleaned before installing any new hose.
After all hoses are installed, always refill the cooling system with correct concentration of coolant, refer to 3.3 Draining
and Filling Cooling System and pressure test cooling system, refer to 3.7 Pressure Testing in this Section.

Figure 6B1 – 27
Legend
1 Radiator Hose – Upper
2 Radiator Hose – Lower
3 Hose Clamp – Upper Hose to Engine Outlet Housing 4 Hose Clamp – Upper Hose to Radiator Inlet
5 Hose Clamp – Lower Hose to Radiator Outlet
6 Hose Clamp – Lower Hose to Engine Coolant Inlet Pipe

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Engine Cooling – V6 Engine Page 6B1–31

3.7 Pressure Testing
Coolant Filler Cap Pressure Testing

Refer to 3.1 Service Notes in this Section, for
important safety items.




1 Allow engine to cool to ambient temperature (less than 50 ° C), then remove coolant filler cap.
2 Inspect and clean both sides (1) of coolant filler cap gasket with a wet cloth.
NOTE
Use only water to wet the cleaning cloth.
Figure 6B1 – 28
3 Lift centre vacuum valve. Clean and inspect the gasket and sealing surface under the valve (1).
Figure 6B1 – 29

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Engine Cooling – V6 Engine Page 6B1–32

4 Attach coolant filler cap (2) to a commercially
available cooling system pressure tester (1), using
the pressure cap adaptor.
5 Slowly pressurise cap to 120 – 130 kPa. The cap is serviceable if it unloads slightly above this pressure
range and holds pressure at 120 kPa.
NOTE
Should the cap fail to reach or hold the
specified pressure, replace the cap.

Figure 6B1 – 30
6 Prior to installing coolant filler cap ensure that the coolant filler neck cap seating surface is clean and
free from obstruction.
Figure 6B1 – 31
Cooling System Pressure Testing

Refer to 3.1 Service Notes in this Section, for
important safety items.
1 Allow the engine to cool to ambient temperature (less than 50 ° C), then remove coolant filler cap.
2 Ensure that the coolant level is correct.

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Engine Cooling – V6 Engine Page 6B1–33

3 Install the coolant filler neck adaptor, to a
commercially available cooling system pressure tester
(1).
4 Install the assembly to the engine coolant filler neck.
5 Using compressed air, blow dry any spilled coolant around coolant filler neck.

Do not exceed the stated pressure, as
damage to the cooling system could
otherwise result.
6 Using the cooling system pressure tester pump, pressurise cooling system to 130 kPa absolute
maximum and check for leaks at the following points:
• All hoses and hose connections
• Overflow hose connection at coolant outlet
housing connection

Figure 6B1 –
––
–
32
• Radiator seams and core
• Corroded or faulty engine W elch plugs
• Coolant pump and gasket
• Thermostat housing and coolant inlet pipe connection
• Radiator drain tap and bleed screw
• Vehicle heating system (e.g. heater core and water valve)
NOTE
For heater Removal and Installation, refer to 2A –
Heater and Air-conditioning.
7 Check engine oil dipstick for evidence of engine oil contamination with coolant.
8 If pressure will not hold, there is a leak in the cooling system. Repair as necessary.
NOTE
If visible loss of coolant is not evident from
pressure testing, then the use of a dye and black
light, may be necessary. Refer to 4.7 Black
Light and Dye Leak Diagnosis Method, in this
Section.

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