Isuzu engine 4j series. Manual - part 63

6B - 12  ENGINE COOLING

RADIATOR

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

6. Cushion Rubber

•

Remove cushion rubbers on both sides of the bottom.

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ENGINE COOLING  6B - 13

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 radiator
valve. If the valve opening pressure is out of the
standard value range, replace with a new radiator
valve.

Radiator valve opening pressure

kPa (kg/cm

2

/psi)

                                                                                                                  

93 - 123 (0.95 - 1.25/13.5 - 17.8)

                                                                                                                  

•

Remove the radiator valve and check a negative
pressure valve as the center of the valve seat side. If
the negative pressure valve does not work smoothly,
clean or replace the radiator valve.

Radiator valve fixing torque

N∙m (kg∙m/lb ft)

                                                                                                                  

6 (0.6/4)

                                                                                                                  

•

Conduct cooling system leakage check after
reinstalling the radiator valve.

Radiator Core

•

Deformed radiator fins could reduce radiation effects,
resulting in overheat. Straighten the fins. In such a
case, take care not to damage the fin roots.

•

Remove dust and other foreign materials.

Flushing the Radiator

•

Wash the inside of radiator and the coolant passage
with water and neutral detergent. Remove all scales
and rust.

Checking for Coolant Leakage

•

Clog up the reserver tank hose carefully and check the
cooling system for leakage with a radiator cap tester
by applying an air pressure of 147 kPa (1.5 kg/cm

2

/21

psi) from filler neck to inside the radiator.

•

As the radiator upper tank is provided with a valve, the
pressure fails to rise higher than the valve opening
pressure unless the hose is clogged up.

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6B - 14  ENGINE COOLING

INSTALLATION

7. Radiator Assembly

•

Install the radiator

6. Cushion Rubber

•

Install cushion rubbers on both sides of radiator
bottom.

•

Install radiator assembly with hose, taking care not to
damage the radiator core by a fan blade.

5. Condenser

4. Radiator Stay

3. Air Intake Duct

•

Connect the Duct and tighten clip securely.

2. Radiator Hose

•

Connect inlet hose and outlet hose to the engine.

•

Connect battery ground cable.

•

Pour coolant

•

Pour coolant up to filler neck of radiator, and up to
MAX mark of reservoir tank.

1. Reservoir Tank Hose & Bypass Hose

•

Start engine to warm up, and check for coolant level.

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ENGINE COOLING  6B - 15

DRIVE BELT ADJUSTMENT

INSPECTION

Check drive belts for wear or damage, and replace with
new ones as necessary. Check belts for tension, and
adjust as necessary.

•

Check drive belts tension.

•

Push the middle of belts with a force of 98 N
(10 kg/22 lb) and check each bolt for deflection.

•

Standard deflection

mm (in)

Tension at readjustment

AC generator & fan pulley
drive belt
A/C compressor drive belt
P/S pump drive belt

8 ~ 12 (0.31 ~ 0.47)

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