radiator cap Lexus GS450h 2007 Instrument cluster / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. OWNER'S MANUAL (OM30727U)

361
4-3. Do-it-yourself maintenance
4
Maintenance and care
Engine compartment
■12 volt battery
P. 3 7 1
Engine oil level dipstick 
( P. 363)
Engine oil filler cap 
( P. 364)
Brake fluid reservoir (P. 370)
Fuse box ( P. 395)Washer fluid tank 
( P. 3 74 )
Gasoline engine/inverter 
coolant reservoir ( P. 368)
Electric cooling fans
Condenser ( P. 369)
Radiator ( P. 369)

368
4-3. Do-it-yourself maintenance
Coolant
The coolant level is satisfactory if it is between the “FULL” and “LOW”
lines on the reservoir when the hybrid system is cold.
Reservoir cap
Full
Low
If the level is on or below the
“LOW” line, add coolant up to the
“FULL” line.
■If the coolant level drops within a short time after replenishing
Visually check the radiator, hoses, reservoir cap, radiator cap, drain cock and water
pump
. 
If you cannot find a leak, have your Lexus dealer pressure test the cap and check for
le
aks in the cooling system.
■Coolant selection
Only use “Toyota Super Long Life Coolant” or similar hig
h quality ethylene glycol
based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life
hybrid organic acid technology.
U.S.A.: “Toyota Super Long Life Coolant” is a
mixture of 50% coolant and 50%
deionized water. (Enabled: -31F [-35 C])
Canada: “Toyota Super Long Life Coolant” is a mixture of 55% coolant and 45% de
ionized water. (Enabled: -44 F [-42C])
For more details about engine/inverter coolant, contact your Lexus dealer.

369
4-3. Do-it-yourself maintenance
4
Maintenance and care
Radiator and condenser
Check the radiator and condenser and clear any foreign objects. 
If either of the above parts are extremely dirty or you are not sure of their
condition, ha

ve your vehicle checked by your Lexus dealer.
CAUTION
■When the coolant may be hot
Do not remove the radiator cap. 
The cooling system may be under pressure and may spray hot coolant if the cap is
removed, causing burns or other injuries.
NOTICE
■When adding the coolant
Coolant is neither plain water not straight antifreeze. The correct mixture of water
and anti freeze must be used to provide proper lubrication, corrosion protection
and cooling. Be sure to read the antifreeze or coolant label.
■If you spill coolant
Be sure to wash it off with water to prevent it damage to parts or paint.
CAUTION
■The radiator and condenser may be hot after driving
To prevent burns, do not touch the radiator or condenser after driving.

476
5-2. Steps to take in an emergency
■Overheating
In the following situations, your vehicle may be overheating.
●The message “HYBRID SYSTEM OVERHEAT” is displayed on the multi-infor-
mation display.
●The engine coolant temperatur e gauge enters the red zone or a loss of power is
experienced.
●Steam is coming from under the hood.
CAUTION
■To prevent an accident or injury when in specting under the hood of your vehicle
●Keep hands and clothing away from the fan and engine drive belt while the hybrid
system is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot. 
Serious injury, such as burns, may resu lt from hot coolant and steam released
under pressure.
Add coolant if required.
Water can be used in an emer -
gency measure if coolant is
una
vailable. ( P. 4 8 4 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos -
sible.
STEP6