HONDA 6. COOLING SYSTEM SERVICE INFORMATION 6-1 THERMOSTAT 6-4 TROUBLESHOOTING 6-1 RADIATOR/COOLING FAN 6-8 SYSTEM TESTING 6-2 WATER PUMP 6-12 COOLANT REPLACEMENT 6-3 SERVICE INFORMATION GENERAL WARNING 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. • Use only distilled water and ethylene glycol in the cooling system. A 50-50 mixture is recommended for maximum corrosion 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. • All cooling system service can be made with the engine in the frame. • Avoid spilling coolant on painted surfaces. • After servicing the system, check for leaks with a cooling system tester. • Refer to Section 21 for fan motor thermostatic switch and temperature sensor inspections. SPECIFICATIONS Radiator cap relief pressure 0.75-1.05 kg/cm2 (10.7-14.9 psi) 55% Distilled water + 45% ethy ene glycol: —32°C (-25°F) Freezing point (Hydrometer test): 50% Distilled water + 50% ethylene glycol: —37°C (-34°F) 45% Distilled water + 55% ethy ene glycol: —44.5°C (-48°F) Coolant capacity: Radiator and engine V45 SABRE V45 MAGNA Reserve tank Total system 2.4 liters (2.5 US qt) 2.4 liters (2.5 US qt) 0.4 liters (0.42 US qt) 0.45 liters (0.48 US qt) 2.8 liters (2.96 US qt) 2.85 liters (3.0 US qt) Thermostat Begins to open: 80° to 84°C (176° to 183°F) Valve lift: Minimum of 8 mm at 95°C (0.315 in. at 203°F) Boiling point (with 50-50 mixture): Unpressurized: 107.7°C (226°F) Cap on, pressurized: 125.6°C (258°F) TOOLS Special Cooling system Tester Commercially available re- TROUBLESHOOTING Engine temperature too high 1. Faulty temperature gauge or gauge sensor 2. Thermostat stuck closed 3. Faulty radiator cap 4. Insufficient coolant 5. Passages blocked in radiator, hoses, or water jacket 6. Fan blades bent 7. Faulty fan motor Engine temperature too low 1. Faulty temperature gauge or gauge sensor 2. Thermostat stuck open Coolant leaks 1. Faulty pump mechanical seal 2. Deteriorated 0-rings 83 Date of Issue: May, 1982 0 HONDA MOTOR CO., LTD. 6-1