Lexus ES-300 2001 Manual page 433

ENGINE
62E006b
" 1 Reservoir cap
2 Upper line
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 ethylene–glycol
type coolant for a proper corrosion protection of
aluminum components.
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.
Always use ethylene–glycol type coolant for a proper
corrosion protection of aluminum components. See
information in the next column.
416
3 Lower 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, 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.