MAINTENANCE G. COOLING SYSTEM Coolant Use fresh water or normal tap water as a coolant. Do not use strong acid or alkaline water. Use the coolant with genuine Hitachi Long-Life Coolant (LLC) mixed by 30 to 50 %. If the air temperature is expected to fall below 0°C (32°F), fill the cooling system with an genuine Hitachi Long-Life Cool- ant (LLC) and soft water mix. As a general rule, the ratio of LLC should range between 30% and 50% as shown in the table below. If the ratio is below 30%, the system may de- velop rust, and if it is above 50%, the engine may overheat. 7-65