2005 Honda Civic Owner's Manual - Page 162
2005 Honda Civic Manual
Page 162 highlights
Engine Coolant 3. The coolant level should be up to the base of the filler neck. Add coolant if it is low. Pour the coolant slowly and carefully so you do not spill. Clean up any spill immediately; it could damage components in the engine compartment. 4. Put the radiator cap back on and tighten it. Maintenance RADIATOR CAP RESERVE TANK 1. When the radiator and engine are cool, relieve any pressure in the cooling system by turning the radiator cap counterclockwise, without pressing down. 2. Remove the radiator cap by pushing down and turning counterclockwise. 5. Pour coolant into the reserve tank. Fill it to halfway between the MAX and MIN marks. Put the cap back on the reserve tank. Do not add any rust inhibitors or other additives to your vehicle's cooling system. They may not be compatible with the coolant or engine components. 163