2021 HYUNDAI TUCSON HYBRID engine coolant

Maintenance
9-6
While operating your vehicle:
• Note any changes in the sound of the
exhaust or any smell of exhaust fumes
in the vehicle.
• Check for vibrations in the steering
wheel. Notice if there is any increased
steering effort or looseness in the
steering wheel, or change in its
straight-ahead position.
• Notice if your vehicle constantly turns
slightly or “pulls” to one side when
traveling on smooth, level road.
• When stopping, listen and check for
unusual sounds, pulling to one side,
increased brake pedal travel or “hard-
to-push” brake pedal.
• If any slipping or changes in the
operation of your transmission occurs,
check the transmission fluid level.
• Check the automatic transmission P
(Park) function.
• Check the parking brake.
• Check for fluid leaks under your
vehicle (water dripping from the air
conditioning system during or after
use is normal).
At least monthly:
• Check coolant level in the engine
coolant reservoir.
• Check the operation of all exterior
lights, including the stoplights, turn
signals and hazard warning flashers.
• Check the inflation pressures of all
tires including the spare for tires that
are worn, show uneven wear, or are
damaged.
• Check for loose wheel lug nuts.
At least twice a year:
• Check radiator, heater and air
conditioning hoses for leaks or
damage.
• Check windshield washer spray and
wiper operation. Clean wiper blades
with a clean cloth dampened with
washer fluid.
• Check headlamp alignment.
• Check muffler, exhaust pipes, shields
and clamps.
• Check the seat belts for wear and
function.
At least once a year:
• Clean body and door drain holes.
• Lubricate door hinges and hood
hinges.
• Lubricate door and hood locks and
latches.
• Lubricate door rubber weather strips.
• Check the air conditioning system.
• Inspect and lubricate automatic
transmission linkage and controls.
• Clean the battery and terminals.
• Check the brake fluid level.

Maintenance
9-8
The following maintenance services must be performed to ensure good emission control and performance.
Keep receipts for all vehicle emission services to protect your warranty. Where both mileage and time are shown, the frequency of
service is determined by whichever occurs first.
MAINTENANCE INTERVALS
MAINTENANCE
ITEM Number of months or driving distance, whichever comes first
Months 12 24 36 48 60 72 84 96 108 120 132 144 156 168 180 Milesx1,000 8 16 24 32 40 48 56 64 72 80 88 96 104 112 120Kmx1,000 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195
HSG belts
*1
Inspect every 8,000 miles (13,000 km) or 12 months,
and replace every 56,000 miles(90,000 km) or 84 months
Engine oil and engine oil filter
*2 *3
R R R R R R R R R R R R R R R
Fuel additives
*4
Add every 8,000 miles (13,000 km) or 12 months
Air cleaner filter I I R I I R I I R I I R I I R
Spark plugs Replace every 46,000 miles (75,000 km)
Rotate tires Rotate tires every 8,000 miles (13,000 km)
Climate control air filter I R I R I R I R I R I R I R I
Vacuum hose I I I I I I I I I I I I I I I
Engine coolant / Inverter coolant At first, replace at 80,000 miles (130,000 km) or 10 years.
After that, replace every 24,000 miles (39,000 km) or 24 months
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace or change.*1 : The drive belt should be replaced when cracks occur or tension is reduced excessively.
*2 : Requires API SN PLUS (or above) grade engine oil. If a lower grade engine oil is used, then the engine oil and engine oil filter
must be replaced at every 5,000 miles (8,000 km) or 6 months as indicated for severe maintenance condition.
*3 : As it is normal for engine oil to be consumed during driving, the amount of engine oil should be checked regularly.
*4 : If TOP TIER Detergent Gasoline is not available, one bottle of additive is recommended. Additives are available from your
authorized HYUNDAI dealer along with information on how to use them. Do not mix other additives.
Normal Maintenance Schedule

09
9-13
Engine oil and filter
The engine oil and filter should be
changed at the intervals specified in the
maintenance schedule. If the vehicle
is being driven in severe conditions,
more frequent oil and filter changes are
required.
HSG (Hybrid Starter & Generator)
belt
The HSG belt should be changed at the
intervals specified in the maintenance
schedule.
Fuel lines, fuel hoses and
connections
Check the fuel lines, fuel hoses and
connections for leakage and damage.
We recommend an authorized HYUNDAI
dealer replace any damaged or leaking
parts immediately.
Fuel filter
A clogged filter can limit the speed
at which the vehicle may be driven,
damage the emission system and cause
multiple issues such as hard starting. If
an excessive amount of foreign matter
accumulates in the fuel tank, the
filter may require replacement more
frequently. After installing a new filter,
run the engine for several minutes,
and check for leaks at the connections.
Fuel filters should be installed by an
authorized HYUNDAI dealer.
Vapor hose and fuel filler cap
The vapor hose and fuel filler cap should
be inspected at those intervals specified
in the maintenance schedule. Your
HYUNDAI dealer will help to determine if
replacement is needed.
Air cleaner filter
A genuine HYUNDAI air cleaner filter
is recommended when the filter is
replaced.
Spark plugs
Make sure to install new spark plugs of
the correct heat range.
When installing new spark plugs, be sure
that the ignition coils are clean and free
of any oil or debris. Clean and wipe off
the bottom portion of the ignition coil in
order to prevent any contamination with
the spark plug during installation.
WARNING
Do not remove spark plugs from the
vehicle when the engine is hot. You
may damage the engine and may also
risk burn injury.
Cooling system
Check cooling system components, such
as radiator, coolant reservoir, hoses and
connections for leakage and damage.
Replace any damaged parts.
Engine coolant/inverter coolant
The coolant should be changed at the
intervals specified in the maintenance
schedule.
Automatic transmission fluid
The automatic transmission fluid level
does not need to be checked under
normal usage conditions.
We recommend that the automatic
transmission fluid is changed by an
authorized HYUNDAI dealer according to
the maintenance schedule.
Explanation of schEdulEd maintEnancE itEms

09
9-15
Checking the engine oil level
Engine oil is used for lubricating,
cooling, and operating various hydraulic
components in the engine. Engine oil
consumption while driving is normal,
and it is necessary to check and refill the
engine oil regularly. Also, check and refill
the oil level within the recommended
maintenance schedule to prevent
deterioration of oil performance.
Check the engine oil following the below
procedure.
1.
Follo
w all of the oil manufacturer’s
precautions.
2.
Be sure the v

ehicle is on the level
ground in P (Park) with the parking
brake set and the wheels blocked.
3.
Turn the engine on and w

arm
the engine up until the coolant
temperature reaches a constant
normal temperature.
4.
Turn the engine o

ff, remove the oil
filler cap and pull the dipstick out.
Wait for 15 minutes for the oil to return
to the oil pan.
5.
Wipe the dipstick clean and r

e-insert
it fully.
ONX4H090002
6. Pull the dipstick out again and check
the le vel. The level should be between
F (Full) and L (Low).
ONX4H090020
7. Check if the oil lev el is between the
F-L line and refill it if the oil level is
below the L, add enough oil to bring
the level to F.
Use only the specified engine oil (Refer
to “Recommended Lubricants and
Capacities” section in chapter 2).
NOTICE
To prevent damage to your engine:
• Do not overfill with engine oil. Add oil
in small quantities and recheck level
to ensure engine is not overfilled.
• The engine oil consumption may
increase while you break in a new
vehicle and it will be stabilized after
driving 3,750 miles.
• The engine oil consumption can be
affected by driving habits, climate
conditions, traffic conditions,
oil quality, etc. Therefore, it is
recommended that you inspect the
engine oil level regularly and refill it
if necessary.
EnginE oil

09
9-17
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the
factory.
Check the antifreeze protection and
coolant level at least once a year, at
the beginning of the winter season and
before traveling to a colder climate.
Checking the coolant level
„„Engine coolant
ONX4H090004
„„Inverter coolant
ONX4H090005
Check the condition and connections
of all cooling system hoses and
heater hoses. Replace any swollen or
deteriorated hoses.
The coolant level should be filled
between the MAX and the MIN marks on
the side of the coolant reservoir when
the engine is cool.If the coolant level is low, add the
selected
an

ti-freeze according to the
proper
coolan
t mix ratio
t
o bring the level
to the MAX mark, but do not overfill.
If frequent additions are required, we
recommend that you see an authorized
HYUNDAI dealer for a cooling system
inspection.
„„Engine coolant cap
ONX4H090006
„„Inverter coolant cap
ONX4H090007
WARNING
Never remove the engine
coolant cap and/or inverter
coolant cap or the drain plug
while the engine and radiator
are hot. Hot coolant and steam
may blow out under pressure,
causing serious injury.
EnginE coolant/invErtEr coolant

Maintenance
9-18
Turn the vehicle off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
cap and/or inverter coolant cap. Wrap
a thick towel around it, and turn it
counterclockwise slowly to the first
stop. Step back while the pressure is
released from the cooling system. When
you are sure all the pressure has been
released, press down on the cap, using
a thick towel, and continue turning
counterclockwise to remove it.
Information
The engine coolant and/or inverter coolant
level is influenced by the hybrid system
temperature. Before checking or refilling
the engine coolant and/or inverter coolant,
turn the hybrid vehicle off.
WARNING
The electric motor for the cooling fan
may continue to operate or start up
when the engine is not running and
can cause serious injury. Keep hands,
clothing and tools away from the
rotating fan blades of the cooling fan.
Always turn off the vehicle unless the
vehicle has to be inspected with the
engine on. Be cautious as the cooling
fan may operate if the negative (-)
battery terminal is not disconnected.
WARNING
Make sure the coolant cap is properly
closed after refilling coolant. Otherwise
the engine could be overheated while
driving.
„„Engine compartment front view
OTMH090008
1. Check if the coolant cap label is
straight In front.
„„Engine compartment rear view
ONX4H090008
2. Make sure that the tiny protrusions
inside the c oolant cap is securely
interlocked.

09
9-19
Recommended coolant
• When adding coolant, use only
deionized water, distilled water or soft
water for your vehicle and never mix
hard water in the coolant filled at the
factory.
• An incorrect coolant mixture can
result in severe malfunction or
engine/hybrid system damage.
• The engine in your vehicle has
aluminum engine parts and must be
protected by an phosphate-based
ethylene glycol coolant to prevent
corrosion and freezing.
• Do not use alcohol or methanol
coolant or mix them with the specified
coolant.
• Do not use a solution that contains
more than 60% antifreeze or less than
35% antifreeze, which would reduce
the effectiveness of the solution.
For mixing percentage, refer to the
following table:
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
5°F (-15°C) 35 65
-13°F (-25°C) 40 60
-31°F (-35°C) 50 50
-49°F (-45°C) 60 40
Information
If in doubt about the mix ratio, a 50%
water and 50% antifreeze mix is the
easiest to mix together as it will be the
same quantity of each. It is suitable to
use for most temperature ranges of -31°F
(-35°C) and higher.
Changing coolant
We recommend that coolant be changed
by an authorized HYUNDAI dealer
according to the Maintenance Schedule
at the beginning of this chapter.
WARNING
Do not use engine coolant or antifreeze
in the washer fluid reservoir.
Engine coolant can severely obscure
visibility when sprayed on the
windshield and may cause loss of
vehicle control resulting in an accident.
Engine coolant may also cause damage
to paint and body trim.
NOTICE
To prevent damage to engine parts, put
a thick towel around the engine coolant
cap and/or inverter coolant cap before
refilling the coolant to prevent the
coolant from overflowing into engine
parts, such as the alternator.

09
9-21
washEr fluid
Checking the washer fluid level
ONX4H090010
Check the fluid level in the washer fluid
reservoir and add fluid if necessary.
Plain water may be used during summer
months if washer fluid is not available.
However, use washer solvent with
antifreeze characteristics in cold climates
to prevent freezing.
WARNING
To prevent serious injury or death, take
the following safety precautions when
using washer fluid:
• Do not use engine coolant or
antifreeze in the washer fluid
reservoir. Engine coolant can
severely obscure visibility when
sprayed on the windshield and
may cause loss of vehicle control
resulting in an accident or damage to
paint and body trim.
• Do not allow sparks or flame to
contact the washer fluid or the
washer fluid reservoir. Washer fluid
may contain alcohol and can be
flammable.
• Do not drink washer fluid and avoid
contact with skin. Washer fluid is
harmful to humans and animals.
• Keep washer fluid away from
children and animals.
WARNING
Do not allow brake fluid to come in
contact with your eyes. If brake fluid
comes in contact with your eyes, flush
your eyes with clean water for at least
15 minutes and get immediate medical
attention.
NOTICE
• Do not allow brake fluid to contact
the vehicle’s body paint, as paint
damage will result.
• Brake fluid, which has been exposed
to open air for an extended time
should NEVER be used as its quality
cannot be guaranteed. It should be
disposed of properly.
• Do not use the wrong kind of brake
fluid. A few drops of mineral based
oil, such as engine oil, in your brake
system can damage brake system
parts.
Information
Use only the specified brake fluid (refer
to “Recommended Lubricants and
Capacities” section in chapter 2).