2001 Toyota Prius Owners Manual - Page 217

Checking brake fluid 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. Your coolant must contain ethylene-glycol type coolant for a proper corrosion protection of your hybrid system that contains aluminum components. Use "TOYOTA Long Life Coolant" or equivalent. In addition to preventing freezing and subsequent damage to the hybrid system, this type of coolant will also prevent corrosion. Further supplemental inhibitors or additives are neither needed nor recommended. Read the coolant container for information on freeze protection. Follow the manufacturer's directions for how much to mix with plain water (preferably demineralized water of distilled water). The total capacity of the cooling system is given on page 234 in Section 9. We recommend to use 50% solution for your Toyota, to provide protection down to about -35°C (-31°F). When it is extremely cold, to provide protection down to about -50°C (-58°F), 60% solution is recommended. Do not use more than 70% solution for better coolant performance. 82p002a NOTICE Do not use alcohol type antifreeze or plain water alone. To check the fluid level, simply look at the see-through reservoir. The level should be between the "MAX" and "MIN" lines on the reservoir. It is normal for the brake fluid level to go down slightly as the brake pads wear or when the fluid level in the accumulator is high. If the reservoir needs frequent refueling, it may indicate a serious mechanical problem. 210