2020 LEXUS NX300 radiator

3286-2. Maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
Radiator/con-
denser
The radiator and con-
denser should be free
from foreign objects.
( P.339)
Washer fluidIs there sufficient washer
fluid? ( P.342)
Vehicle interior
ItemsCheck points
Accelerator
pedal
The accelerator pedal
should move smoothly
(without uneven pedal
effort or catching).
Automatic
transmission
“Park” mecha-
nismWhen parked on a slope
and the shift lever is in P,
is the vehicle securely
stopped?
Brake pedal
• Does the brake pedal
move smoothly?
• Does the brake pedal have appropriate
clearance from the
floor?
• Does the brake pedal have the correct
amount of free play?
ItemsCheck points
Brakes
• The vehicle should not pull to one side when
the brakes are
applied.
• The brakes should work effectively.
• The brake pedal should not feel
spongy.
• The brake pedal should not get too
close to the floor
when the brakes are
applied.
Head restraints
Do the head restraints
move smoothly and lock
securely?
Indica-
tors/buzzersDo the indicators and
buzzers function prop-
erly?
LightsDo all the lights come
on?
Parking brake
• Does the parking brake switch operate
normally?
• When parked on a slope and the parking
brake is on, is the vehi-
cle securely stopped?
Seat belts
•Do the seat belts operate smoothly?
• The seat belts should not be damaged.
ItemsCheck points

3316-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
6-3.Do-it-yourself maintenance
Do-it-yourself service pre-
cautions
If you perform maintenance by
yourself, be sure to follow the cor-
rect procedure as given in these
sections.
Maintenance
ItemsParts and tools
Battery condi-
tion (P.340)
•Warm water
• Baking soda
•Grease
• Conventional wrench
(for terminal clamp
bolts)
Brake fluid level
( P.340)
•FMVSS No.116 DOT
3 or SAE J1703;
FMVSS No.116 DOT
4 or SAE J1704 brake
fluid
• Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/inter-
cooler coolant
level ( P.338)
•“Toyota Super Long
Life Coolant” or a sim-
ilar high quality eth-
ylene glycol-based
non-silicate, non-
amine, non-nitrite and
non-borate coolant
with long-life hybrid
organic acid technol-
ogy
For the U.S.A.:
“Toyota Super Long
Life Coolant” is pre-
mixed with 50% cool-
ant and 50% deion-
ized water.
For Canada:
“Toyota Super Long
Life Coolant” is pre-
mixed with 55% cool-
ant and 45% deion-
ized water.
• Funnel (used only for adding coolant)
Engine oil level
( P.336)
•“Toyota Genuine
Motor Oil” or equiva-
lent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses
( P.358)Fuse with same amper-
age rating as original
Light bulbs
( P.361)Bulb with same number
and wattage rating as
original
Headlight aimPhillips-head screw-
driver
Radiator and
condenser
( P.339)
—
ItemsParts and tools

3326-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
Tire inflation
pressure
( P.351)• Tire pressure gauge
• Compressed air
source
Washer fluid
( P.342)
• Water or washer fluid
containing antifreeze
(for winter use)
• Funnel (used only for adding water or
washer fluid)
WARNING
The engine compartment contains many
mechanisms and fluids that may move
suddenly, become hot, or become elec-
trically energized. To avoid death or seri-
ous injury, observe the following
precautions.
■When working on the engine com-
partment
●Keep hands, clothi ng and tools away
from the moving fan and engine drive
belt.
●Be careful not to touch the engine,
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 and 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 cautions when working
on the battery. It contains poisonous
and corrosive sulfuric acid.
ItemsParts and tools■When working near the electric cool-
ing fans or radiator grille
Be sure the engine switch is off.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. ( P.339)
■Safety glasses
Wear safety glasses to prevent flying or
falling material, fluid spray, etc. from get-
ting in your eyes.
NOTICE
■If you remove the air cleaner filter
Driving with the air cleaner filter
removed may cause excessive engine
wear due to dirt in the air.

3356-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
Fuse box (P.358)
Engine coolant reservoir ( P.338)
Engine oil filler cap ( P.336)
Engine oil level dipstick ( P.336)
Intercooler coolant reservoir ( P.338)
Battery ( P.340)
Brake fluid reservoir ( P.340)
Radiator ( P.339)
Condenser ( P.339)
Electric cooling fans
Washer fluid tank ( P.342)
Engine compartment
Components
A
B
C
D
E
F
G
H
I
J
K

3396-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
6
Maintenance and care
■Intercooler coolant reservoir
Reservoir cap
“FULL” line
“LOW” line
If the level is on or below the “LOW” line,
add coolant up to the “FULL” line.
■Coolant selection
Only use “Toyota Super Long Life Coolant”
or a 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 mix-
ture of 50% coolant and 50% deionized
water.
(Minimum temperature: -31°F [-35°C])
Canada:
“Toyota Super Long Life Coolant” is a mix-
ture of 55% coolant and 45% deionized
water.
(Minimum temperature: -44°F [-42°C])
For more details about coolant, contact
your Lexus dealer.
■If the coolant level drops within a short
time of replenishing
Visually check the radiator, hoses, engine
coolant reservoir cap, drain cock and water
pump.
If you cannot find a leak, have your Lexus
dealer test the cap and check for leaks in
the cooling system.
Check the radiator and condenser and
clear away any foreign objects.
If either of the above parts is extremely
dirty or you are not sure of their condi-
tion, have your vehicle inspected by
your Lexus dealer.
A
B
C
WARNING
■When the engine is hot
Do not remove the engine coolant reser-
voir and the intercooler coolant reservoir
cap.
The cooling system may be under pres-
sure and may spray hot coolant if the cap
is removed, causing serious injuries, such
as burns.
NOTICE
■When adding coolant
Coolant is neither plain water nor
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 pre-
vent it from damaging parts or paint.
Checking the radiator and con-
denser
WARNING
■When the engine is hot
Do not touch the radiator or condenser
as they may be hot and cause serious
injuries, such as burns.

3406-3. Do-it-yourself maintenance
LEXUS NX300 Owners Manual_USA_M78389_en
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN” lines
on the tank.
■Adding fluid
Make sure to check the fluid type and
prepare the necessary item.
 Fluid type
FMVSS No.116 DOT 3 or SAE J1703;
FMVSS No.116 DOT 4 or SAE J1704
brake fluid
Items
Clean funnel
■Brake fluid can absorb moisture from
the air
Excess moisture in the brake fluid can cause a dangerous loss of braking efficiency. Use
only newly opened brake fluid.
Check the battery as follows.
■Battery exterior
Make sure that the battery terminals
are not corroded and that there are no
loose connections, cracks, or loose
clamps.
Terminals
Hold-down clamp
WARNING
■When the electric cooling fans are
operating
Do not touch the engine compartment.
With the engine switch in IGNITION
ON mode, the electric cooling fans may
automatically start to run if the air condi-
tioning is on and/or the coolant tempera-
ture is high. Be sure the engine switch is
off when working near the electric cool-
ing fans or radiatorgrille.
Checking and adding the brake
fluid
WARNING
■When filling the reservoir
Take care as brake fluid can harm your
hands and eyes and damage painted sur-
faces.
If fluid gets on your hands or in your eyes,
flush the affected area with clean water
immediately.
If you still experience discomfort, see a
doctor.
NOTICE
■If the fluid level is low or high
It is normal for the brake fluid level to go
down slightly as the brake pads wear out
or when the fluid leve l in the accumulator
is high.
If the reservoir need s frequent refilling,
there may be a serious problem.
Checking the battery
A
B

4047-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
radiator core (radiator) for any
leaks.
Radiator
Cooling fans
If a large amount of coolant leaks, immedi-
ately contact your Lexus dealer.
4The coolant level is satisfactory if it
is between the “FULL” and “LOW”
lines on the reservoir.
Engine
Reservoir
“FULL” line
“LOW” line
Intercooler radiatorReservoir
“FULL” line
“LOW” line
5 Add coolant if necessary.
Engine
Water can be used in an emergency if
coolant is unavailable.
Intercooler radiator
Water can be used in an emergency if
coolant is unavailable.
A
B
A
B
C
A
B
C

4057-2. Steps to take in an emergency
LEXUS NX300 Owners Manual_USA_M78389_en
7
When trouble arises
6Start the engine and turn the air
conditioning system on to check
that the radiator cooling fans oper-
ate and to check for coolant leaks
from the radiator or hoses.
The fans operate when the air conditioning
system is turned on immediately after a
cold start. Confirm that the fans are oper-
ating by checking the fan sound and air
flow. If it is difficult to check these, turn the
air conditioning system on and off repeat-
edly.
(The fans may not oper ate in freezing tem-
peratures.)
7If the fans are not operating:
Stop the engine immediately and
contact your Lexus dealer.
If the fans are operating:
Have the vehicle inspected at the
nearest Lexus dealer.
8
Check if “Engine Coolant Temp
High” is shown on the multi-infor-
mation display.
If the message does not disappear:
Stop the engine and contact your
Lexus dealer.
If the message is not displayed:
Have the vehicle inspected at the
nearest Lexus dealer.
WARNING
■To prevent an accident or injury when
inspecting under the hood of your
vehicle
Observe the following precautions.
Failure to do so may result in serious
injury such as burns.
●If steam is seen coming from under the
hood, do not open the hood until the
steam has subsided. The engine com-
partment may be very hot.
●Do not touch within the engine com-
partment or get close when the cool-
ing fan is operating. Body parts,
clothes, etc., may get caught and lead
to an accident, resulting in serious
injury. The cooling fan operates auto-
matically at times when the air condi-
tioner is operating and times when the
coolant temperatures are high. Also, it
may operate for several minutes even
after the engine switch is turned off.
●Keep hands and clothing (especially a
tie, a scarf or a muffler) away from the
fans and belts. Failure to do so may
cause the hands or clothing to be
caught, resulting in serious injury.
●Do not loosen the coolant reservoir
cap while the engine and radiator are
hot.
High temperature steam or coolant
could spray out.
NOTICE
■When adding engine coolant
Add coolant slowly after the engine has
cooled down sufficiently. Adding cool
coolant to a hot engine too quickly can
cause damage to the engine.
■To prevent damage to the cooling sys-
tem
Observe the following precautions:
●Avoid contaminating the coolant with
foreign matter (such as sand or dust,
etc.).
●Do not use any coolant additive.