2008 LEXUS RX400H radiator

306
4-2. Maintenance
RX400h_U
General maintenance
Engine compartment
ItemsCheck points
12-volt batteryMaintenance-free. (→P. 3 2 7 )
Brake fluidAt the correct level? ( →P. 3 2 5 )
Engine/power control unit coolantAt the correct level? ( →P. 3 2 3 )
Engine oilAt the correct level? ( →P. 3 1 8 )
Exhaust systemNo fumes or strange sounds?
Radiator/condenser/hosesNot blocked with foreign matter?
(→ P. 3 2 5 )
Wa s h e r f l u i dAt the correct level? ( →P. 3 2 9 )
Listed below are the general maintenance items that should be performed
at the intervals specified in the “Warranty and Services Guide” or
“Owner’s Manual Supplement”. It is recommended that any problem you
notice should be brought to the attent ion of your Lexus dealer or qualified
service shop for advice.

311
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
ItemsParts and tools
Engine oil level (→P. 3 1 8 )
• “Toyota Genuine Motor Oil” or
equivalent
• Rag or paper towel, funnel (used
only for adding engine oil)
Fuses (→ P. 3 5 2 )• Fuse with same amperage rating as
original
Headlight aim ( →P. 364)• Phillips-head screwdriver
Radiator and condenser (→P. 3 2 5 )
Tire inflation pressure ( →P. 3 4 0 )• Tire pressure gauge
• Compressed air source
Wa s h e r f l u i d ( →P. 3 2 9 )
• Water washer fluid containing anti-
freeze (for winter use)
•Funnel

312
4-3. Do-it-yourself maintenance
RX400h_U
CAUTION
The engine compartment contains many mechanisms and fluids that may move sud-
denly, become hot, or become electrically energized. To avoid death or serious injury:
■When working on the engine compartment
●Keep hands, clothing, and tools away from the moving fan and engine drive belt.
●Be careful not to touch the engine, inverter, radiator, exhaust manifold, etc. right
after driving as they may be hot. Oil and other fluids may also be hot.
●Do not leave anything that may burn easily, such as paper or rags, in the engine
compartment.
●Do not smoke, cause sparks or expose an open flame to fuel or the battery. Fuel
and battery fumes are flammable.
●Be extremely cautious when working on the battery. It contains poisonous and
corrosive sulfuric acid.
●Never touch, disassemble, remove or replace the high voltage parts, cables and
their connectors. It can cause severe burns or electric shock that may result in
death or serious injury.
●When the hybrid system is operating with the READY light on, the engine may
suddenly start in some cases. When you inspect the engine compartment, be
sure to turn off the hybrid system.
■When working near the electric cooling fan or radiator grille
Be sure the engine switch is off.
With the engine switch on, the electric cooling fan may automatically start to run if
the air conditioning is on and/or the coolant temperature is high. (→P. 3 2 5 )
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc. from getting
in the eyes.
NOTICE
■If you remove the air cleaner:
Driving with the air filter removed may cause excessive engine wear due to dirt in
the air. Also a backfire could cause a fire in the engine compartment.

316
4-3. Do-it-yourself maintenance
RX400h_U
Engine compartment
Brake fluid reservoir(→P. 325)
Engine oil level dipstick (→P. 318)
Engine oil filler cap (→P. 318)
Power control unit coolant
reservoir ( →P. 323)
Fuse boxes ( →P. 352)Engine coolant radiator
(→P. 325)
Condenser ( →P. 325)
Power control unit coolant
radiator ( →P. 325)
Electric cooling fans
Engine coolant reservoir (→P. 323)
12-volt battery ( →P. 327)
Washer fluid tank (→P. 329)

324
4-3. Do-it-yourself maintenance
RX400h_U
■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
leaks in the cooling system.
■Coolant selection
Only use Toyota Super Long Life Coolant or similar high 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% deionized water. (Enabled: -44 °F [-42 °C])
For more details about coolant, contact 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 antifreeze 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 damaging parts or paint.

325
4-3. Do-it-yourself maintenance
4
Maintenance and care
RX400h_U
Radiator and condenserCheck 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, have your vehicle checked by your Lexus dealer.
Brake fluid■ Checking fluid level
The brake fluid level should be between the MAX and MIN lines on
the tank.
MAX
MIN
If the level is low, take your vehicle
to a Lexus dealer as soon as possi-
ble. Do not drive your vehicle if the
red brake system warning light is
on. Call a Lexus dealer for assis-
tance.
Make sure to check the fluid type.
CAUTION
■When the engine is hot
Do not touch the radiator or condenser, as they may be hot and you may be burned.

424
5-2. Steps to take in an emergency
RX400h_U
If your vehicle overheats
■Electric motor (traction motor) and inverter
If the message WATER TEMP is displayed on the multi-information
display.
■ Gasoline engine
If the needle of the engine coolant temperature gauge enters the
red zone, the gasoline engine has probably overheated.
Observe the following steps:
Stop the vehicle in a safe place and turn off the automatic air
conditioning system.
Check to see if steam is coming out from under the hood.
If you see steam: Stop the hybrid system. Carefully lift the hood after the
steam subsides and then restart the hybrid system.
If you do not see steam: Leave the hybrid system running and carefully lift the hood.
Check to see if the cooling fan is operating.
If the fan is operating: Wait until the temperature of the engine (shown on the
instrument cluste r) begins to fall and then stop the hybrid
system.
If the fan is not operating: Stop the hybrid system immediately and call your local
Lexus dealer.
After the hybrid system has
cooled down sufficiently, check
the engine coolant level and
inspect the radiator core (radia-
tor) for any leaks.
STEP1
STEP2
STEP3
STEP4

5
When trouble arises
425
5-2. Steps to take in an emergency
RX400h_U
■Overheating
If you observe the following, your vehicle may be overheating.
●The message WATER TEMP is displayed on the multi-information display.
●The engine coolant temperature 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 inspecting under the hood of your vehicle
●If steam is seen coming from under the hood, do not open the hood until the
steam has subsided. The engine compartment may be very hot, causing serious
injury such as burns.
●Keep hands and clothing away from the fan and other belts while the hybrid sys-
tem is running.
●Do not loosen the radiator cap while the hybrid system and radiator are hot.
Serious injury, such as burns, may result from hot coolant and steam released
under pressure.
Add engine coolant if required.
Water can be used in an emer-
gency measure if engine coolant
is unavailable. (→P. 4 3 5 )
Have the vehicle checked at your nearest Lexus dealer as soon as pos-
sible.
STEP5