2006 Lexus GS 300 Owners Manual - Page 551

ENGINE CHECKING THE ENGINE COOLANT LEVEL Look at the see−through coolant reservoir when the engine 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 engine temperature. However, if the level is on or below the "LOW" line, add coolant. Bring the level up to the "FULL" line. G62007 If the coolant level drops within a short time after replenishing, there may be a leak in the system. Visually check the radiator, hoses, engine coolant filler cap, radiator cap and 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. "GS430 1 Reservoir cap 2 "FULL" line 3 "LOW" line CAUTION To prevent burning yourself, do not remove the radiator cap when the engine is hot. G62008 "GS300 1 Reservoir cap 2 "FULL" line 3 "LOW" line 527