Page 1
12. COOLING SYSTEM
12-0
GRAND DINK 125/ 15 0
12
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
__________________________________________________________________________________
COOLING SYSTEM
__________________________________________________________________________________
SCHEMATIC DRAWING ---------------------------------------------- 12- 1
SERVICE INFORMATION -------------------------------------------- 12- 2
TROUBLESHOOTING ------------------------------------------------- 12- 2
COOLING SYSTEM TESTING --------------------------------------- 12- 4
RADIATOR -------------------------------------------------------------- 12- 4
WATER PUMP ---------------------------------------------------------- 12- 9
THERMOSENSOR ------------------------------------------------------ 12-15
THERMOSTAT---------------------------------------------------------- 12-16
12
Page 2
12. COOLING SYSTEM
12-1
GRAND DINK 125/ 15 0
SCHEMATIC DRAWING
Torque: 9.8_ 13.7N-m
Left Hand Threads
＊
Page 3
12. COOLING SYSTEM
12-2
GRAND DINK 125/ 15 0
SERVICE INFORMATION
GENERAL INSTRUCTIONS
• The water pump must be serviced after removing the engine. Other cooling system service can be
done with the engine installed in the frame.
• The engine must be cool before servicing the cooling system.
When the coolant temperature is over 100℃ , never remove the radiator cap to release the
pressure because the boiling coolant may cause danger.
• Avoid spilling coolant on painted surfaces because the coolant will corrode the painted surfaces.
Wash off any spilled coolant with fresh water as soon as possible.
• After servicing the system, check for leaks with a cooling system tester.
SPECIAL TOOL
Mechanical seal driver
TORQUE VALUES
Water pump impeller 9.8_ 13.7N-m
Water pump cover bolt 7.8_ 11.8N-m
TROUBLESHOOTING
Engine temperature too high Coolant leaks
• Faulty temperature gauge or thermosensor • Faulty pump mechanical (water) seal
• Faulty radiator cap • Deteriorated O-rings
• Faulty thermostat • Damaged or deteriorated water hoses
• Insufficient coolant
• Passages blocked in hoses or water jacket
• Clogged radiator fins
• Passages blocked in radiator
• Faulty water pump
Temperature gauge pointer does not register
the correct coolant temperature
• Faulty temperature gauge or thermosensor
• Faulty thermostat
Page 4
12. COOLING SYSTEM
12-3
GRAND DINK 125/ 15 0
SPECIFICATIONS
Radiator cap relief pressure
0.9±0.15kg/cm_
Begins to open
80±2℃
Thermostat temperature
Full-open
90℃
Valve lift
3.5_ 4.5mm
Coolant capacity
Total system
1400±20cc
Radiator: 1000±20cc
Reserve tank: 400±20cc
COOLANT GRAVITY
Temp. ℃
Coolant
concentration
05101520253035404550
5%
1.009
1.009
1.008
1.008
1.007
1.006
1.005
1.003
1.001
0.009
0.997
10%
1.018
1.107
1.017
1.016
1.015
1.014
0.013
1.011
1.009
1.007
1.005
15%
1.028
1.027
1.026
1.025
1.024
1.022
1.020
1.018
1.016
1.014
1.012
20%
1.036
1.035
1.034
1.033
1.031
1.029
1.027
1.025
1.023
1.021
1.019
25%
1.045
1.044
1.043
1.042
1.040
1.038
1.036
1.034
1.031
1.028
1.025
30%
1.053
1.051
1.051
1.049
1.047
1.045
1.043
1.041
1.038
1.035
1.032
35%
1.063
1.062
1.060
1.058
1.056
1.054
1.052
1.049
1.046
1.043
1.040
40%
1.072
1.070
1.068
1.066
1.064
1.062
1.059
1.056
1.053
1.050
1.047
45%
1.080
1.078
1.076
1.074
1.072
1.069
1.056
1.063
1.062
1.057
1.054
50%
1.086
1.084
1.082
1.080
1.077
1.074
1.071
1.068
1.065
1.062
1.059
55%
1.095
1.093
1.091
1.088
1.085
1.082
1.079
1.076
1.073
1.070
1.067
60%
1.100
1.098
1.095
1.092
1.089
1.086
1.083
1.080
1.077
1.074
1.071
COOLANT MIXTURE (WITH ANTI-RUST AND ANTI-FREEZING EFFECTS)
Freezing Point
Mixing Rate
KYMCO SIGMA Coolant Concentrate
Distilled Water
-9℃
20%
-15℃
30%
425cc
975cc
-25℃
40%
-37℃
50%
-44.5℃
55%
Cautions for Using Coolant:
• Use coolant of specified mixing rate. (The
mixing rate of 425cc KYMCO SIGMA
coolant concentrate + 975cc distilled
water is 30%.)
• Do not mix coolant concentrate of
different brands.
• Do not drink the coolant which is
poisonous.
• The freezing point of coolant mixture shall
be 5℃ lower than the freezing point of
the riding area.
Page 5
12. COOLING SYSTEM
12-4
GRAND DINK 125/ 15 0
COOLING SYSTEM TESTING
RADIATOR CAP INSPECTION
Install the radiator cap onto the radiator
tester and apply specified pressure to it. It
must hold specified pressure for at least six
seconds.
Radiator Cap Relief Pressure:
0.9±0.15kg/cm_
Install the radiator tester onto the radiator
and apply specified pressure to it. It must
hold specified pressure for at least six
seconds.
Check the water hoses and connectors for
leaks.
RADIATOR
RADIATOR INSPECTION
Remove the front upper cover. (!2-5)
Remove the front lower cover. (!2-5)
Radiator Cap
Radiator Tester
The test pressure should not exceed 1.05
kg/cm_. Excessive pressure can damage
the radiator and its hose connectors.
＊
Apply water to the cap sealing surface
before testing.
＊
Page 6
12. COOLING SYSTEM
12-5
GRAND DINK 125/ 15 0
Inspect the radiator soldered joints and
seams for leaks.
Blow dirt out from between core fins with
compressed air. If insects, etc., are clogging
the radiator, wash them off.
Carefully straighten any bent fins.
RADIATOR REMOVAL
Drain the coolant. (!3-9)
Disconnect the air vent tube from the
radiator filler.
Remove the overflow tube clamp and
disconnect the overflow tube.
Loosen the hose band and disconnect the
upper hose and lower hose from the
radiator.
Air Vent Tube
Lower Hose
Upper Hose
Overflow Tube
Page 7
12. COOLING SYSTEM
12-6
GRAND DINK 125/ 15 0
Disconnect the thermostatic switch wire
coupler.
Disconnect the fan motor wire coupler.
Remove the two bolts and one nut on the
radiator.
RADIATOR DISASSEMBLY
Remove the four bolts and then remove the
fan/shroud from the radiator.
Fan/Shroud
Radiator
Bolts
Thermostatic Switch Wire
Fan Motor Wire Coupler
Bolts
Thermostatic Switch
Nut
Page 8
12. COOLING SYSTEM
12-7
GRAND DINK 125/ 15 0
Check fan motor by battery.
CHECK THERMOSTATIC SWITCH
When coolant temperature lower then
83~87℃ the thermostatic switch OFF.
When coolant temperature over 88~92℃
the thermostatic switch ON.
Install the fan shroud on the radiator with
the four bolts.
Radiator
Thermostatic Switch
Bolts
Fan Motor
Battery
Fan Shroud
Page 9
12. COOLING SYSTEM
12-8
GRAND DINK 125/ 15 0
RADIATOR INSTALLATION
Install the radiator on the radiator bracket
with the two bolts and one nut.
Connect the upper and lower hoses and
secure them with hose bands.
Connect the thermostatic switch wire and
fan motor wire couplers.
Connect the overflow tube and secure with
the tube clamp.
Connect the vent tube to the radiator filler.
Fill the radiator with coolant. (!3-9)
After installation, check for coolant leaks.
.
Air Vent Tube
Radiator
Upper Hose
Overflow Tube
Lower Hose
Bolts
Thermostatic Switch
Wire
Nut
Page 10
12. COOLING SYSTEM
12-9
GRAND DINK 125/ 15 0
Install the front upper cover.
WATER PUMP
MECHANICAL SEAL (WATER SEAL)
INSPECTION
Inspect the
telltale hole for signs of
mechanical seal coolant leakage.
If the mechanical seal is leaking, remove the
right crankcase cover and replace the
mechanical seal.
WATER PUMP/IMPELLER REMOVAL
Remove the coolant inlet hose and outlet
hose.
Right Crankcase Cover
Telltale Hole
Water Pump
Outlet Hose
Inlet Hose
Page 11
12. COOLING SYSTEM
12-10
GRAND DINK 125/ 15 0
Remove the four bolts and the water pump
cover, gasket and 2 dowel pins.
Remove the water pump impeller.
Inspect the mechanical (water) seal and seal
washer for wear or damage.
Impeller (Left Hand Threads)
Mechanical Seal
Seal Washer (Porcelain)
Water Pump Cover
Bolts
The impeller has left hand threads.
＊
The mechanical seal and seal washer
must be replace as a set.
＊
Impeller
Page 12
12. COOLING SYSTEM
12-11
GRAND DINK 125/ 15 0
WATER PUMP SHAFT REMOVAL
Disconnect the water hose from the right
crankcase cover.
Remove the 3 bolts attaching the water
pump assembly.
Remove the water pump assembly, gasket
and dowel pins.
Remove the water pump bearing snap ring
from the water pump assembly.
Remove the water pump shaft and shaft
inner bearing.
Remove the water pump shaft outer
bearing.
Inner Bearing
Snap Ring
Water Pump Assembly
Bolts
Inner Bearing
Water Pump Assembly
Water Pump Shaft
Water Pump Shaft
Page 13
12. COOLING SYSTEM
12-12
GRAND DINK 125/ 15 0
Water Pump Assembly
MECHANICAL SEAL REPLACEMENT
Drive the mechanical seal out of the water
pump assembly from the inside.
Drive in a new mechanical seal using a
mechanical seal driver.
WATER PUMP SHAFT INS TALLATION
Drive a new water pump shaft
outer bearing
into the water pump assembly from the
inside.
Mechanical Seal (Water Seal)
Mechanical Seal Driver
Water Pump Assembly
Apply sealant to the right crankcase
cover fitting surface of a new mechanical
seal and then drive in the mechanical seal.
＊
Outer Bearing
Page 14
12. COOLING SYSTEM
12-13
GRAND DINK 125/ 15 0
Install the water pump shaft and shaft inner
bearing into the waster pump assembly.
Install the snap ring to secure the inner
bearing properly.
Install the dowel pins and a new gasket and
then install the water pump assembly to the
right crankcase cover.
Tighten the 3 bolts to secure the water
pump assembly.
WATER PUMP/IMPELLER
INSTALLATION
When the mechanical seal is replaced, a new
seal washer must be installed to the
impeller.
Inner Bearing
Snap Ring
Water Pump Shaft
Bolts
Water Pump Assembly
When installing the water pump
assembly, aligning the groove on the
water pump shaft with the tab on the oil
pump shaft.
＊
Mechanical Seal
Seal Washer (Porcelain)
Impeller
Page 15
12. COOLING SYSTEM
12-14
GRAND DINK 125/ 15 0
Install the impeller onto the water pump
shaft.
Torque: 9.8_ 13.7N-m
Install the two dowel pins and a new
gasket.
Install the water pump cover and tighten
the 4 bolts.
Torque: 7.8_ 11.8N-m
Impeller (Left Hand Threads)
Dowel Pins
Water Pump Cover
Bolt
The impeller has left hand threads.
＊
Gasket
Page 16
12. COOLING SYSTEM
12-15
GRAND DINK 125/ 15 0
THERMOSENSOR
THERMOSENSOR REMOVAL
Remove the seat, met-in box and center
cover.
Drain the coolant.
Disconnect the thermosensor wire.
Remove the thermosensor.
THERMOSENSOR INSPECTION
Suspend the thermosensor in a pan of water
over a burner and measure the resistance
through the sensor as the water heats up.
Temperature(
℃ )
5080100
120
Resistance(W)
1545227
16
THERMOSENSOR INSTALLATION
Apply 3-BOND No. 1212 sealant or
equivalent to the thermosensor threads and
install it into the thermostat housing.
Connect the thermosensor wire.
Fill the radiator with coolant. (!3-9)
Install the center cover, met-in box and seat.
(!2-3)
Be sure to bleed air from the cooling
system.
＊
Thermosensor
Thermosensor Wire
Thermosensor
Thermosensor Wire
Thermosensor
Thermometer
Page 17
12. COOLING SYSTEM
12-16
GRAND DINK 125/ 15 0
THERMOSTAT
THERMOSTAT REMOVAL
Remove the seat, met-in box and center
cover.
Drain the coolant.
Disconnect the thermosensor wire from the
thermosensor.
Disconnect the water hose from the
thermostat housing.
Disconnect the air vent tube from the
thermostat housing.
Remove the mounting bolt and the
thermostat housing from the cylinder head.
Remove the two bolts and separate the
thermostat housing halves.
Remove the thermostat from the thermostat
housing.
Thermostat Housing
Thermostat
Bolts
Thermostat
Water Hose
Air Vent Tube
Bolt
Page 18
12. COOLING SYSTEM
12-17
GRAND DINK 125/ 15 0
THERMOSTAT INSPECTION
Suspend the thermostat in a pan of water
over a burner and gradually raise the water
temperature to check its operation.
Technical Data
Begins to open
80±2℃
Full-open
90℃
Valve lift
3.5_ 4.5mm
THERMOSTAT INSTALLATION
The installation sequence is the reverse of
removal.
Fill the cooling system with the specified
coolant. (!3-9)
• Do not let the thermostat touch the pan
as it will give a false reading.
• Replace the thermostat if the valve
stays open at room temperature.
•Test the thermostat after it is opened
for about 5 minutes and holds the
temperature at 70℃ .
＊
O-ring
Thermostat Housing
Thermostat Housing
Replace the O-ring with a new one and
apply grease to it.
＊
Thermostat
Thermometer
Loading...