2023 TOYOTA TUNDRA HYBRID coolant reservoir

4576-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
Fuse boxes ( P.486)
Power control unit coolant reservoir ( P.460)
Intercooler coolant reservoir ( P.460)
Engine coolant reservoir ( P.460)
Engine oil filler cap ( P.458)
Engine oil level dipstick ( P.458)
Brake fluid reservoir ( P.461)
Engine radiator ( P.461)
Condenser ( P.461)
Electric cooling fans
Radiator cooling fan ( P.460)
Washer fluid tank ( P.462)
Intercooler radiators ( P.460)
Engine compar tment
Components

4606-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
The coolant level is satisfactory
if it is between the “F” and “L”
lines on the reservoir when the
hybrid system is cold.
Engine coolant Engine coolant reservoir cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up
to the “F” line.
(  P.535)
Intercooler coolant
Intercooler coolant reservoir
cap
“F” line
“L” line
If the level is on or below the “L”
line, add coolant up to the “F” line.
(  P.535)
Power control unit coolant
Power control unit coolant
reservoir cap
“FULL” line
NOTICE
■To prevent serious engine
damage
Check the oil level on a regular
basis.
■When replacing the engine oil
●Be careful not to spill engine oil
on the vehicle components.
●Avoid overfilling, or the engine
could be damaged.
●Check the oil le vel on the dip-
stick every time you refill the
vehicle.
●Be sure the engine oil filler cap
is properly tightened.
■If oil is spilled on the engine
cover
To prevent the engine cover from
being damaged, remove any
engine oil from the engine cover
as soon as possible using a neu-
tral detergent. Do not use an
organic solvent such as brake
cleaner.
Checking the coolant

4616-3. Do-it-yourself maintenance
Owners Manual_USA_M0C052_en
6
Maintenance and care
“LOW” line
If the level is on or below the “LOW”
line, add coolant up to the “FULL”
line. ( P.535)
■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 mixture of 50% coolant
and 50% deionized water.
(Minimum temperature: -31°F [-
35°C])
Canada: “Toyota Super Long Life
Coolant” is a mixture of 55% coolant
and 45% deionized water.
(Minimum temperature: -44°F [-
42°C])
For more details about coolant, con-
tact your Toyota dealer.
■If the coolant level drops within
a short time of replenishing
Visually check the radiator, hoses,
engine coolant reser voir cap, inter-
coolant reservoir cap, 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 sys-
tem.
Check the radiator, condenser
and intercooler radiators 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.
■Checking fluid level
The brake fluid level should be
between the “MAX” and “MIN”
WARNING
■When the hybrid system is
hot
Do not remove the coolant reser-
voir cap.
The cooling system may be under
pressure and may spray hot cool-
ant 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.
Checking the radiator,
condenser and inter-
cooler radiators
WARNING
■When the hybrid system is
hot
Do not touch the radiator, con-
denser or intercooler radiators or
condenser as they may be hot
and cause serious injuries, such
as burns.
Checking and adding the
brake fluid

5357-2. Steps to take in an emergency
Owners Manual_USA_M0C052_en
7
When trouble arises
■If the engine coolant tem-
perature gauge enters the
red zone or “Engine Cool-
ant Temp High Stop in a
Safe Place See Owner’s
Manual” is shown on the
multi-information display
1 Stop the vehicle in a safe
place and turn off the air con-
ditioning system, and then
stop the hybrid system.
2 If you see steam:
Carefully lift the hood after
the steam subsides.
If you do not see steam:
Carefully lift the hood.
3 After the hybrid system has
cooled down sufficiently,
inspect the hoses, engine
radiator core (radiator) and
intercooler radiator core
(radiator) for any leaks.
If a large amount of coolant leaks,
immediately cont act your Toyota dealer.
Cooling fan
Radiator
Intercooler radiators
4 The coolant level is satisfac-
tory if it is between the “F” or
“FULL” and “L” or “LOW”
lines on the reservoir.
If your vehicle overheats
The following may indicate that your vehicle is overheating.
The needle of the engine coolant temperature gauge ( P.91)
enters the red zone or a loss of engine (hybrid system) power i s
experienced. (For example, the vehicle speed does not
increase.)
 “Engine Coolant Temp High Stop in a Safe Place See Owner’s
Manual” is shown on the multi-information display.
Steam comes out from under the hood.
Correction procedures

5367-2. Steps to take in an emergency
Owners Manual_USA_M0C052_en
Engine
Reservoir
“F” line
“L” line
IntercoolerReservoir
“F” line
“L” line
Power control unitReservoir “FULL” line
“LOW” line
5 Add coolant if necessary.
Water can be used in an emer-
gency if coolant is unavailable.
If water was added in an emer-
gency, have the v ehicle inspected
at your Toyota dealer as soon as
possible.
Engine
Intercooler
Power control unit