MAINTENANCE MANUAL OF GW4D20/GW4D20B TURBOCHARGED DIESEL ENGINES
422
Great Wall Baoding Internal Combustion Engine
Manufacturing Company Limited
Fig. 7-2-21 Checking the thermostat
Fig. 7-2-22 Checking the thermostat valve lift
Fig. 7-2-23
①
Installing the thermostat and Its
shield
Check and Repair
(1) Immerse the thermostat assembly in the
noncorrosive neutral clear water as shown in Fig.
7-2-21.
(2) Put the wooden block at the bottom of the water
container. Do not heat the thermostat directly. See
Fig. 7-2-21.
(3) Elevate water temperature progressively and
constantly mix it to make the water temperatures in
the container uniform.
——Ensure that thermostat main valve opens at
specified temperature.
Temperature for thermostat valve to open:
76
℃
——Confirm that the second valve of thermostat fully
opens at specified temperature.
Temperature for thermostat valve to fully open:
88
℃
If any severe wear or damage is found on the
thermostat during the check, then the necessary
repair and parts replacement shall be performed.
(4) Check the thermostat valve lift as shown in Fig.
7-2-22.
The valve lift shall be at least 8.5 mm in the case of a
water temperature at 88
℃
.
If the valve lift does not accord with the requirements,
the thermostat assembly shall be replaced.
Installation
Installing the thermostat shield
④
(1) Clean the thermostat chamber on the left side of
cylinder body.
(2) Install the thermostat cap into the thermostat
chamber on the left side of cylinder body, and ensure
its installation is in place as shown in Fig. 7-2-23.
Installing the thermostat
③
(1) Check whether the rubber seal ring on thermostat
assembly correctness is correctly installed.
(2) Install the thermostat assembly into the
thermostat shield of cylinder body as shown in Fig.
7-2-23.
Thermometer
Heated water
Thermostat
Wooden block
Size of
fully-open
valve
The valve lift shall be at least 8.5 mm in the
case of a water temperature at 88
℃
.
Cylinder
body
Thermostat
shield
Thermostat
