12. COOLING SYSTEM Downtown 125 i
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 1.2 kgf-m (12 N-m, 9 lbf-ft) Left hand threads
Water pump cover bolt 1.0 kgf-m (10 N-m, 7 lbf-ft)
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
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