2021 TOYOTA AVALON HYBRID radiator

3946-2. Maintenance
General maintenance
Listed below are the general maintenance items that should be
performed at the intervals specified in the “Owner’s Warranty
Information Booklet” or “Owner’s Manual Supplement/Sched-
uled Maintenance Guide”. It is recommended that any problem
you notice should be brought to the attention of your Toyota
dealer or qualified service shop for advice.
Engine compartment
ItemsCheck points
Brake fluidIs the brake fluid at the correct
level? (P. 409)
CoolantIs the coolant at the correct level?
(P. 407)
Engine oilIs the engine oil at the correct level?
(P. 404)
Exhaust systemThere should not be any fumes or
strange sounds.
Radiator/condenser
The radiator and condenser should
be free from foreign objects.
(P. 408)
Washer fluidIs there sufficient washer fluid?
(P. 410)
Tr u nk
ItemsCheck points
12-volt battery Check the connections. (P. 4 1 1 )

399
6
Maintenance and care
6-3. Do-it-yourself maintenance
Do-it-yourself ser vice precautions
If you perform maintenance by yourself, be sure to follow the
correct procedure as given in these sections.
ItemsParts and tools
12-volt battery
condition
(P. 411)•Grease
• Conventional wrench (for terminal clamp bolts)
Brake fluid level
(P. 409)
• SAE J1703 or FMVSS No.116 DOT 3
SAE J1704 or FMVSS No.116 DOT 4
• Rag or paper towel
• Funnel (used only for adding brake fluid)
Engine/power
control unit cool-
ant level
(P. 407)
• “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
“Toyota Super Long Life Coolant” is pre-mixed with
50% coolant and 50% deionized water.
• Funnel (used only for adding coolant)
Engine oil level
(P. 404)• “Toyota Genuine Motor Oil” or equivalent
• Rag or paper towel
• Funnel (used only for adding engine oil)
Fuses (P. 442)• Fuse with same amperage rating as original
Hybrid battery
(traction battery)
air intake vent
(P. 434)
• Vacuum cleaner, etc.
• Phillips screwdriver
Radiator/con-
denser (
P. 408)

4006-3. Do-it-yourself maintenance
Tire inflation
pressure
(P. 427)• Tire pressure gauge
• Compressed air source
Washer fluid
(P. 410)• Water or washer fluid containing antifreeze (for win-
ter 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 electrically energized. To avoid death
or serious injury, observe the following precautions.
■When working on the engine compartment
●Make sure that the “ACCESSORY” or “IGNITION ON” on the multi-infor-
mation display and the “READY” indicator are both off.
●Keep hands, clothing and tools away from the moving fan and engine
drive belt.
●Be careful not to touch the engine, power control unit, 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. Fuel fumes
are flammable.
■When working near the electric cooling fan or radiator grille
Be sure the power switch is off.
With the power switch in ON mode, the electric cooling fan may automati-
cally start to run if the air conditioning is on and/or the coolant temperature
is high. (P. 408)
■Safety glasses
Wear safety glasses to prevent flying or falling material, fluid spray, etc.
from getting 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.
ItemsParts and tools

4036-3. Do-it-yourself maintenance
6
Maintenance and care
Engine compartment
Fuse boxes (P. 442)
Engine oil filler cap (P. 405)
Engine oil level dipstick
(P. 404)
Brake fluid reservoir
(P. 409)
Radiator (P. 408)Electric cooling fan
Condenser (P. 408)
Power control unit
coolant reservoir (P. 407)
Engine coolant reservoir
(P. 407)
Washer fluid tank (P. 410)1
2
3
4
5
6
7
8
9
10

4086-3. Do-it-yourself maintenance
■If the coolant level drops within a short time of replenishing
Visually check the radiators, hoses, engine/power control unit coolant reser-
voir caps, drain cock and water pump.
If you cannot find a leak, have your Toyota 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 condition, have your vehicle inspected by your Toyota dealer.
WARNING
■When the hybrid system is hot
Do not remove the engine/power control unit coolant reservoir caps or the
radiator cap.
The cooling system may be under pressure 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 prevent it from damaging parts or paint.
Radiator and condenser
WARNING
■When the hybrid system is hot
Do not touch the radiator or condenser as they may be hot and cause seri-
ous injuries, such as burns.

4947-2. Steps to take in an emergency
■If the needle of the engine coolant temperature gauge enters
the red zone or “Engine Coolant Temp High Stop in a Safe
Place See Owner’s Manual” is shown on the multi-information
display
Stop the vehicle in a safe place and turn off the air conditioning sys-
tem, and then stop the hybrid system.
If you see steam:
Carefully lift the hood after the steam subsides.
If you do not see steam:
Carefully lift the hood.
After the hybrid system has
cooled down sufficiently,
inspect the hoses and radiator
core (radiator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant leaks,
immediately contact your Toyota
dealer.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
●The needle of the engine coolant temperature gauge (P. 98)
enters the red zone or a loss of hybrid system power is experi-
enced. (For example, the vehicle speed does not increase.)
●“Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” or “Hybrid System Overheated Output Power Reduced”
is shown on the multi-information display
●Steam comes out from under the hood.
Correction procedures
1
2
3
1
2

4957-2. Steps to take in an emergency
7
When trouble arises
The coolant level is satisfactory
if it is between the “F” and “L”
lines on the reservoir.
Reservoir
“F” line
“L” line
Radiator cap
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
Start the hybrid system and turn the air conditioning system on to
check that the radiator cooling fan operates and to check for cool-
ant leaks from the radiator or hoses.
The fan operates when the air conditioning system is turned on immedi-
ately after a cold start. Confirm that the fan is operating by checking the fan
sound and air flow. If it is difficult to check these, turn the air conditioning
system on and off repeatedly. (The fan may not operate in freezing tem-
peratures.)
If the fan is not operating:
Stop the hybrid system immediately and contact your Toyota dealer.
If the fan is operating:
Have the vehicle inspected at the nearest Toyota dealer.
4
1
2
3
4
5
6
7

4967-2. Steps to take in an emergency
■If “Hybrid System Overheated Output Power Reduced” is
shown on the multi-information display
Stop the vehicle in a safe place.
Stop the hybrid system and carefully lift the hood.
After the hybrid system has
cooled down, inspect the
hoses and radiator core
(radiator) for any leaks.
Radiator
Cooling fan
If a large amount of coolant
leaks, immediately contact
your Toyota dealer.
The coolant level is satisfac-
tory if it is between the
“FULL” and “LOW” lines on
the reservoir.
Reservoir
“FULL”
“LOW”
Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
1
2
3
1
2
4
1
2
3
5