TAYO Zontes ZT125-M 2022, Maintenance Manual

Page: 138 / 188

138 / 188
1-Water tank front guard bolt*4 2-Water tank front guard 3-Water tank 4-Fan nut 5-Fan 6-Fan motor
7-Fan Guard 8-Fan Guard Bolt*3 9-Fan Motor Bolt*3
6. Water and oil shared sensor
For details on sensor detection and disassembly methods, please refer to the section "Electronic Injection System" chapter EFI
Parts Fault Diagnosis and Elimination.
7. Thermostat
7.1 Inspection
Check the appearance for damage and leakage.
Simple test method (test on the whole vehicle):
After the cold car is started, immediately open the water filler cap. If there is no fluctuation
in the liquid level, the thermostat is normal, otherwise it is abnormal. Check that when the
water temperature is lower than 70°C (158 F), the thermostat should be in a closed state. When
the temperature is higher than the initial opening temperature, the expansion valve of the
expansion cylinder will gradually open, and the circulating coolant in the radiator will begin to
flow.
After the temperature rises, check the inlet pipe of the small water tank. You should be able to clearly feel the signs of water
flow or the temperature of the pipe wall, otherwise the pump or waterway will be blocked.
When the temperature reaches 80°C (176 F), the heating rate slows down, and the thermostat works normally. If the water
temperature has been rising rapidly, when the internal pressure reaches a certain level, the sudden overflow of boiling water
indicates that the valve is stuck.
If it is stuck or closed loosely, it can be removed and cleaned or repaired first, otherwise it should be replaced.
7.2 Failure phenomenon
When the water temperature gauge indicates high, the engine temperature is overheated, but the coolant temperature in the
water tank is not high, it is not hot when touching the radiator by hand, and the small water tank fan rotates normally. It
indicates that the big circulation is blocked or blocked, which can be preliminarily judged as abnormal thermostat.
There are generally two cases of abnormal thermostat:
a. The main valve is closed for a long time, and the coolant is circulated in a small circulation route regardless of the water
temperature, which causes the engine to overheat.
b. The main valve is in the open state for a long time, and the phenomenon is that the water temperature rises slowly when
starting, especially in winter, the slow rise of the coolant temperature makes the engine not work at the normal temperature,
and the engine temperature is too low.
7.3 Disassembly
Checking method of thermostat assembly:
Seal the two ports, pass in compressed air of 181 kPa (1.85 Kgf/cm2, 26.3 psi) from the other port, put it in the water and let it
stand to see if there are bubbles, if there is leakage.