2007 Toyota Prius Owners Manual - Page 424

CAUTION The coolant heat storage tank reaches high temperature inside. It is dangerous if hot coolant is discharged when replacing. For replacement of the coolant, contact your Toyota dealer. Look at the see−through coolant reservoir when the hybrid system is cold. The coolant level is satisfactory if it is between the "FULL" and "LOW" lines on the reservoir. If the level is low, add the coolant. (For the coolant type, see "Coolant type selection" described below.) The coolant level in the reservoir will vary with hybrid system temperature. However, if the level is on or below the "LOW" line, add coolant. Bring the level up to the "FULL" line. If the coolant level drops within a short time after replenishing, there may be a leak in the system. Visually check the radiator, hoses, radiator cap and drain cock and water pump. If you can find no leak, have your Toyota dealer test the cap pressure and check for leaks in the cooling system. If the fluid level in the inverter coolant reservoir is low, there may be a problem with the cooling system. Have the vehicle checked by your Toyota dealer. For Canada-"Toyota Super Long Life Coolant" is a mixture of 55% coolant and 45% deionized water. This coolant provides protection down to about −42_C ( −44_F). NOTICE Do not use plain water alone. CAUTION To prevent burning yourself, do not remove the radiator cap when the engine is hot. Coolant type selection Use of improper coolants may damage your cooling system. Only use "Toyota Super Long Life Coolant" or similar high quality ethylene glycol based non−silicate, non−amine, non−nitrite, and non−borate coolant with long−life hybrid organic acid technology. (Coolant with long−life hybrid organic acid technology is a combination of low phosphates and organic acids.) For the U.S.A.-"Toyota Super Long Life Coolant" is a mixture of 50% coolant and 50% deionized water. This coolant provides protection down to about −35_C ( −31_F). 407