Isuzu NHR 4J Series, Workshop Manual

Page: 47 / 406

SERVICE INFORMATION 00 – 43
needle position of water thermomete, conduct a
5 minutes idling again and stop the engine.
10 When the engine has been cooled, check filler neck
for water level and replenish if required. Should
extreme shortage of coolant is found, Check the
coolant system and reservoir tank hose for leakage.
11 Fill the coolant into the reservoir tank up to “MAX”
line.
Cooling System Inspection
Install a radiator filler cap tester to the radiator. Apply testing
pressure to the cooling system to check for leakage.
The testing pressure must not exceed the specified pressure.
Testing Pressure
kPa (Kg/cm
2
/psi)
147 (1.5/21)
Radiator Cap Inspection
The radiator filler cap is designed to maintain coolant
pressure in the cooling system at 1.05 kg/cm
2
(15 psi / 103
kPa). Check the radiator filler cap with a radiator filler cap
tester. The radiator filler cap must be replaced if it fails to
hold the specified pressure during the test procedure.
Radiator Filler Cap Pressure
Pressure Valve
kPa (Kg/cm
2
/psi)
88 - 118 (0.9 - 1.2/12.8 - 17.1)
Negative Valve (Reference) kPa (Kg/cm
2
/psi)
1.0 - 13.9 (0.01 - 0.04/0.14 - 0.57)
Thermostat Operating Test
1. Completely submerge the thermostat in water.
2. Heat the water.
Stir the water constantly by suitable wood bar (2) to
avoid direct heat being applied use wood plate (3) to
the thermostat.
3. Check the thermostat initial opening temperature.
Thermostat Initial
Opening Temperature
°C (°F)
82 (180)
4. Check the thermostat full opening temperature.
Thermostat Full
Opening Temperature
°C (°F)
95 (203)
Valve Lift at Fully Open Position mm (in)
10 (0.39)
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