Cooling System - Honda Hawk GT NT650 1988 Service Manual

5. COOLI NG SYSTEM
SERVICE INFORMATION
TROUBLESHOOTING
SYSTEM TESTING
COOLANT REPLACEMENT
SERVICE INFORMATION
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THERMOSTAT
RADIATOR/COOLING FAN
WATER PUMP
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GENERAL
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Do not remove the radiator cap when the engine is hot. The coolant is under pressure and severe scalding could result. The engine
must be cool before servicing the cooling system.
If the engine must be running to do some work, make sure the area is well-ventilated. Never run the engine in an enclosed area.
The exhaust contains poisonous carbon monoxide gas that may cause loss of consciousness and lead
to
death.
• Use only distilled water and ethylene glycol in the cooling system. A 50- 50 mixture is recommended for maximum corro-
sion protection. Do not use alcohol-based antifreeze.
• Add coolant at the reserve tank. Do not remove the radiator cap except to refill. or drain the system. or to test the coolant
mixture.
• Avoid spilling coolant on painted surfaces.
• After servicing the system, check for leaks with a cooling system tester.
• For temperature sensor and thermostatic switch inspection, refer to section 18.
SPECIFICATIONS
ITEM SPECIFICATIONS
Radiator cap relief pressure 88-127 kPa (0.9-1.3 kg/cm
2 ,
13-18 psi)
Freezing point (Hydrometer test): 55% Distilled water
+
45% ethylene glycol: -32°C
(-25°F)
50% Distilled water
+
50% ethylene glycol: -37°C
(-34°F)
45% Distilled water
+
55% ethylene glycol: -44.5°C (-48°F)
Coolant capacity: Coolant change: 1.60 lit (1.51 US qt, 1.28 Imp qt)
Total system: 2.20 lit (2.32 US qt, 1.94 Imp qt)
Thermostat
Begins to open: 80° to 84°C (176° to 183°F)
Valve lift: Minimum of 8 mm at 95°C (0.3 in at 203°F)
Boiling point (with 50- 50 mixture):
Unpressurized: 107.7°C (226°F)
Cap on, pressurized: 125.6°C (258°F)
TROUBLESHOOTI NG
Engine temperature too high
Faulty temperature gauge or sensor
Thermostat stuck closed
Faulty radiator cap
Insufficient coolant or coolant level too low
Passages blocked in radiator, hoses or water jacket
Cooling fan motor does not turn
- Burned or loose sub-fuse
- Faulty fan motor
- Faulty thermostatic switch
- Poor connector contact or open circuit in harness
Faulty water pump
Engine temperature too low
• Thermostat stuck open
Coolant leaks
Faulty pump mechanical seal
• Deteriorated a-rings
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