MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
60
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 2-12-14 Checking the cooling system
with a tester
Fig. 2-12-15 Checking the water filler cover
with a tester
system. Because they may be incompatible with the
coolant or engine parts.
See Fig. 2-12-13 to determine the correct mixing ratio of
coolant and water.
5.2 Check for the cooling system
Mount the radiator tester on the radiator. Apply the test
pressure to the cooling system to check leakage. See
Fig. 2-12-14.
The test pressure should not exceed the specified
pressure.
196 kPa
5.3 Check for the radiator cover
The radiator filler cover is designed to keep a 88 ~ 118
kPa pressure in the cooling system. Check if the filler
cover meets requirements with a radiator filler cover
tester. See Fig. 2-12-15.
During testing, the radiator filler cover must be replaced if
it cannot keep the specified pressure.
Design pressure of the
radiator filler cover
Pressure valve
88
～
118 kPa
Negative pressure valve
(reference value)
1.0
～
3.9 kPa
Radiator filler cover tester: 5-8840-2036-0.
Fig. 2-12-16 Checking the lift of thermostat
valve
5.4 Check for the thermostat mounting assembly
5.4.1 Check for the thermostat cover and thermostat
Check if the thermostat cover and thermostat are
deformed; they must be replaced if deformed.
5.4.2 Operation test for the thermostat
(1) Dip the thermostat completely in water.
(2) Heat the water and stir it to avoid direct heating to the
thermostat.
(3)
Observe
temperature
changes
through
the
thermometer in the water; check the initial opening
temperature of the thermostat.
Initial opening temperature of the thermostat
76
℃
± 2
℃
(4) Check the temperature when the thermostat is
completely opened. See Fig. 2-12-17.
Temperature when the thermostat is completely opened
