Isuzu D-Max / Isuzu Rodeo (TFR/TFS). Manual — part 1701

ENGINE COOLING 6B-9

Thermostat

Removal

1. Disconnect battery ground cable.

2. Drain engine coolant from the radiator and engine.

3. Disconnect radiator hose from the inlet pipe.

4. Remove thermostat housing.

5. Remove thermostat from thermostat housing.

Inspection

Suspend the thermostat in a water-filled container using thin
wire. Place a thermometer next to the thermostat.
Do not directly heat the thermostat.
Gradually increase the water temperature. Stir the water so
that the entire water is same temperature.
Confirm the temperature when the valve first begins to open.

Valve opening temperature 92

°°°°C (197.6°°°°F)

Confirm the temperature when the valve is fully opened.

Valve full open temperature 107

°°°°C(224.6°°°°F)

Make necessary repair and parts replacement if extreme wear
or damage is found during inspection.

Installation

1. Before installing thermostat, coat sealing surface with

silicon grease.

2. Install O-ring.

3. Install thermostat housing and tighten bolts to the specified

torque.

Torque: 15 N

⋅⋅⋅⋅m (1.5 kgf⋅⋅⋅⋅m)

4. Installation rubber hose.

5. Replenish engine coolant (EC).

6. Start engine and check for EC leakage.

Fan Clutch with Cooling Fan

Inspection and Repair

Make necessary correction or parts replacement if wear,

damage or any other abnormal condition are found through

inspection.

Visually inspect for damage, leak (silicon grease) or other

abnormal conditions.

1. Inspection (on-vehicle)

1)

Turn the fan clutch by hand when in a low temperature
condition before starting the engine, and confirm that it
can be turned readily.

2)

Start the engine to warm it up until the temperature at the
fan clutch portion gets to around 80

°C. Then stop the

engine and confirm that the fan clutch can be turned with
considerable effort (clutch torque) when turned by hand.

6B-10 ENGINE COOLING

If the fan clutch rotates more readily, however, this
indicates that the silicon grease is leaking internally.
Replace the fan clutch with a new one.

2. Inspection (in unit)

Warm up the bimetal of the fan clutch by using the heat gun

until the temperature gets to about 80

°C when measured

with the thermistor. Then confirm that the fan clutch can be

turned with considerable effort (clutch torque).

If the fan clutch retates more readily at this time, this

indicates that the silicon grease is leaking internally.

Replace the fan clutch with a new one.

ENGINE COOLING 6B-11

Radiator

Radiator and Associated Parts

Legend

1 Radiator
2 Radiator Cap
3 Radiator Upper Hose

4 Radiator Lower Hose
5 Cooling Fan Shroud
6 Cooling Fan

Removal

1. Disconnect battery ground cable.

2. Loosen a drain plug to drain engine coolant (EC).

3. Disconnect radiator inlet hose and outlet hose.

4. Disconnect the reserve tank hose from radiator.

5. Lift out the radiator assembly, taking care not to damage the

radiator core.

6B-12 ENGINE COOLING

Inspection

Radiator Cap

Measure the valve opening pressure of the pressurizing valve
with a radiator filler cap tester.
Replace the cap if the valve opening pressure is outside the
standard range.

Valve opening pressure kPa (psi) 88.3 - 1117.7

(13.5 - 17.8)

Cap tester: 5-8840-0277-0
Adapter: 5-8840-2603-0
Check the condition of the vacuum valve in the center of the
valve seat side of the cap. If considerable rust or dirt is found,
or if the valve seat cannot be moved by hand, clean or replace
the cap.

Valve opening vacuum kPa (psi) 1.9 - 4.9

(0.28 - 0.71)

Radiator Core

1. A bent fin may result in reduced ventilation and overheating

may occur. All bent fins must be straightened. Pay close

attention to the base of the fin when it is being straightened.

2. Remove all dust, bugs and other foreign material.

Flushing the Radiator

Thoroughly wash the inside of the radiator and the engine
coolant passages with cold water and mild detergent. Remove
all sign of scale and rust.

Cooling System Leakage Check

Use a radiator cap tester to force air into the radiator through
the filler neck at the specified pressure of 196 kPa (28.5 psi)
with a cap tester:
• Leakage from the radiator
• Leakage from the coolant pump
• Leakage from the water hoses
• Check the rubber hoses for swelling.
Cap tester: 5-8840-0277-0
Adapter: 5-8840-2603-0