1997 Lexus SC 400 Owners Manual - Page 219

ENGINE 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, drain cock and water pump. If you can find no leak, have your Lexus dealer test the cap pressure and check for leaks in the cooling system. CHECKING THE ENGINE FAN FLUID (SC400 ONLY) ! CAUTION To prevent burning yourself, do not remove the radiator cap when the engine is hot. Engine coolant selection Your coolant must contain ethylene-glycol antifreeze. In addition to preventing freezing and subsequent damage to the engine, this will also prevent corrosion. Further supplemental inhibitors or additives are neither needed nor recommended. Read the antifreeze container for information on freeze protection. Follow the manufacturer's directions for how much to mix with water. The total capacity of the cooling system is given on page 201. We recommend 50% solution be used for your Lexus, or a sufficient quantity to provide protection to about -35_C (-31_F). Park the vehicle at a level spot and look at the see-through reservoir. If necessary, add automatic transmission fluid DEXRONRII or III. NOTICE Do not use alcohol type antifreeze or plain water alone. 210