General Information; Trouble Diagnosis - Sym HD 125 Service Manual

12. COOLING SYSTEM

General Information

General
Warning:
While the engine is running, never attempt to open the radiator filler cap, the pressurized hot coolant
may shoot out and cause serious scalding injury. No maintenance work is allowed to perform unless
the engine is completely cooled down.
Refill the radiator with distilled water or specified additives.
Add coolant to the reservoir.
The cooling system can be serviced on the motorcycle.
Never spill the coolant to the painted surface.
Test the cooling system for any leakage after the repair.
Please refer to Section 17 for inspection of the temperature sensor switch for the fan motor and the
water thermometer.
Technical Specification
Item
Pressure to open filler cap
Capacity of coolant: Engine + radiator
Reservoir upper
Thermostat
Boiling point
Torque Value
For water pump rotor
Tools Requirement
Special tools
Water pump bearing driver (6901): SYM-9100100
Water pump oil seal driver (Inner): SYM-9120500-H9A
Water pump mechanical seal driver: SYM-1721700-H9A
Inner bearing puller: SYM-6204020

Trouble Diagnosis

The engine temperature is too high
The water thermometer and the temperature
sensor do not work properly.
The thermostat is stuck to closed.
Insufficient coolant.
The water hose and jacket are clogged.
Fan motor malfunction.
The filler cap of the radiator malfunction.
To this chapter contents
Begins to activate at 71-80¢ J
1.0~1.4kgf-m
The engine temperature is too low
The water thermometer and the temperature
sensor malfunction.
The thermostat is stuck to open.
Coolant is leaking
The water pump mechanical seal does not
function properly.
The O ring is deteriorated.
The water hose is broken or aged.
Specification
2
0.75~1.05 kg/cm
780 c.c.
420 c.c.
Stroke: 3.5 ~ 4.5 mm/80¢ J
Not-pressure: 107.7¢ J
Pressurized: 125.6¢ J
12-2