Isuzu N-Series. Service manual - part 606

6B-10 ENGINE COOLING

4JB1

Tighten:

• Generator Fixing Belt to 40 N

⋅m (4.1 kg⋅m/30 lb⋅ft)

• Adjust Plate Fixing Belt to 19 N

⋅m (1.9 kg⋅m/14 lb⋅ft)

• A/C Idler Pulley Lock Nut to 27 N

⋅m (2.8 kg⋅m/20 lb⋅ft)

• P/S Idler Pulley Lock Nut to 27 N

⋅m (2.8 kg⋅m/20 lb⋅ft)

8. Cooling Fan Assembly

• Mount fan pulley and cooling fan assembly on the

water pump and tighten to the specified torque.

Tighten:
Fan Pulley Nut to 8 N

⋅m (0.8 kg⋅m/69 lb⋅in)

9. Fan Shroud

• Install the fan shroud and reservoir tank hose and

bypass hose.

• Connect the battery ground cable.
• Pour coolant.
• Start the engine and check coolant leakage.

mm (in)

Initial tension

AC Generator drive belt
A/C compressor drive belt
Power Steering pump drive belt

8 — 12

(0.31 — 0.47)

Legend

1. A/C compressor drive belt & P/S pump drive 

belt

2. AC generator & fan pulley drive belt

N6A3295E

N6A3379E

ENGINE COOLING 6B-11

THERMOSTAT

Component

Removal

Preparation:

• Disconnect battery ground cable.
• Drain coolant from the radiator and engine.

1. Switch Harness
2. Outlet Pipe

• Remove mounting bolt and remove outlet pipe to-

gether with radiator hose.

3. Gasket
4. Thermostat

Inspection

Submerge the thermostat assembly in the water.
Place wooden blocks on the bottom of the water con-
tainer.
Not to directly heat the thermostat.
Gradually increase the water temperature. Stir the water
so that the entire water is same temperature.

• Make sure that primary valve begins to open at the

specified temperature.

• Make sure that secondary valve opens fully at the

specified temperature.

Legend

1. Switch harness

3. Gasket

2. Outlet pipe

4. Thermostat

N6A3385E

Valve Opening Temperature

°C(°F)

82 (180)

Valve Full Open Temperature

°C(°F)

95 (203)

6B-12 ENGINE COOLING

Make necessary repair and parts replacement if ex-
treme wear or damage is found during inspection.

Installation

1. Thermostat
2. Gasket
3. Outlet Pipe

• Connect outlet pipe and tighten bolts to the speci-

fied torque.

Tighten:
19 N

⋅m (1.9 kg⋅m/14 lb⋅ft)

4. Switch Harness

• Install switch harness.

• Install battery ground cable.
• Pour coolant.
• Start the engine and check coolant leakage.

N6A3386E

N6A3387E

ENGINE COOLING 6B-13

RADIATOR

Component

Removal

Preparation:

• Disconnect battery ground cable.
• Loosen drain plug to drain coolant.

1. Reservoir Tank Hose & Bypass Hose

• Disconnect the hose from radiator.

2. Radiator Hose

• Disconnect lower hose and upper hose from the

engine.

3. Air Intake Duct
4. Radiator Stay
5. Condenser

• Remove the condenser from radiator and tempo-

rarily tighten the condenser to cab body front side,
use the wire.

6. Cushion Rubber

• Remove cushion rubbers on both sides of the bot-

tom.

7. Radiator Assembly

• Remove upward the radiator assembly with hose,

taking care not to damage the radiator core by fan
blade.

Inspection

Radiator Valve

• Apply air pressure from filler neck using radiator

cap tester and check the opening pressure of radi-
ator valve. If the valve opening pressure is out of
the standard value range, replace with a new radi-
ator valve.

Legend

1. Reservoir tank hose & Bypass hose

5. Condenser

2. Radiator hose

6. Cushion rubber

3. Air intake duct

7. Radiator assembly

4. Radiator stay

N6A3388E

Radiator valve opening pressure

kPa (kg/cm

2

 /psi)

93 — 123 (0.95 — 1.25/13.5 — 17.8)