2021 HYUNDAI SONATA chapter 6

Maintenance
8-20
Checking the Engine Oil and
Filter
Have engine oil and filter changed by an
authorized HYUNDAI dealer according
to the Maintenance Schedule at the
beginning of this chapter.
WARNING
CALIFORNIA PROPOSITION 65
WARNING
Engine oil contains chemicals known to
the State of California to cause cancer,
birth defects and reproductive harm.
Used engine oil may cause irritation or
cancer of the skin if left in contact with
the skin for prolonged periods of time.
Always protect your skin by washing
your hands thoroughly with soap and
warm water as soon as possible after
handling used oil.

08
8-23
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.
The electric motor for the cooling
fan is controlled by engine coolant
temperature, refrigerant pressure and
vehicle speed. As the engine coolant
temperature decreases, the electric
motor will automatically shut off. This
is a normal condition. If your vehicle is
equipped with GDI, the electric motor
for the cooling fan may begin to operate
at any time and continue to operate until
you disconnect the negative battery
cable.
Changing Engine Coolant
Have coolant 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 radiator cap
before refilling the coolant to prevent
the coolant from overflowing into
engine parts, such as the alternator.

Maintenance
8-24
Checking the Brake Fluid Level
ODN8089005
Check the fluid level in the reservoir
periodically. The fluid level should be
between MAX and MIN marks on the side
of the reservoir.
Before removing the reservoir cap and
adding brake fluid, clean the area around
the reservoir cap thoroughly to prevent
brake fluid contamination.
If the level is low, add the specified brake
fluid to the MAX level. The level will fall
with accumulated mileage. This is a
normal condition associated with the
wear of the brake linings. If the fluid level
is excessively low, have the brake system
checked by an authorized HYUNDAI
dealer.
WARNING
If the brake system requires frequent
additions of fluid this could indicate
a leak in the brake system. Have the
vehicle inspected by an authorized
HYUNDAI dealer.
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” in chapter 2).
BraKE fluid

08
8-27
1. Pull up the lever (1) on the air cleaner
cover and release the lock.
2.

Pull up the air cleaner co
ver (2) and
open.
3.

R
otate the fixed lever (3) on the filter
and loosen the lock.
4.
R

eplace the air cleaner filter.
5.

Assemble in r
everse order.
Information
If the vehicle is operated in extremely
dusty or sandy areas, replace the element
more often than the usual recommended
intervals (refer to “Maintenance Under
Severe Usage Conditions” in this chapter).
NOTICE
• Do not drive with the air cleaner filter
removed. This will result in excessive
engine wear.
• When removing the air cleaner filter,
be careful that dust or dirt does not
enter the air intake, or damage may
result.
• Use HYUNDAI genuine parts. Use of
non-genuine parts could damage the
air flow sensor.

08
8-33
• The negative battery cable must
be removed first and installed last
when the battery is disconnected.
Disconnect the battery charger in the
following order:
1.

T
urn off the battery charger main
switch.
2.

U
nhook the negative clamp from
the negative battery terminal.
3.

U
nhook the positive clamp from
the positive battery terminal.
• Always use a genuine HYUNDAI
approved battery when you replace
the battery.
By jump starting
After a jump start from a good battery,
drive the vehicle for 20-30 minutes
before it is shutoff. The vehicle may
not restart if you shut it off before the
battery had a chance to adequately
recharge. See “Jump Starting” in chapter
7 for more information on jump starting
procedures.
Information
An inappropriately disposed
battery can be harmful to
the environment and human
health. Dispose of the battery
according to your local law(s) or
regulations.
Reset Features
The following items may need to be reset
after the battery has been discharged or
the battery has been disconnected. See
chapter 3 or 4 for:
• Power Windows
• Trip Computer
• Climate Control System
• Clock
• Audio System
• Sunroof

Maintenance
8-34
WARNING
Tire failure may cause loss of
vehicle control resulting in an
accident. To reduce risk of SERIOUS
INJURY or DEATH, take the
following precautions:
• Inspect your tires monthly for
proper inflation as well as wear
and damage.
• The recommended cold tire
pressure for your vehicle can be
found in this manual and on the
tire label located on the driver’s
side center pillar. Always use a
tire pressure gauge to measure
tire pressure. Tires with too
much or too little pressure wear
unevenly causing poor handling.
• Check the pressure of the
spare every time you check the
pressure of the other tires on
your vehicle.
• Replace tires that are worn, show
uneven wear, or are damaged.
Worn tires can cause loss of
braking effectiveness, steering
control, or traction.
• ALWAYS replace tires with
the same type, size, brand,
construction and tread pattern
as each tire that was originally
supplied with this vehicle. Using
tires and wheels other than the
recommended sizes could cause
unusual handling characteristics,
poor vehicle control, or
negatively affect your vehicle’s
Anti-Lock Brake System (ABS)
resulting in a serious accident.
Tire Care
For proper maintenance, safety, and
maximum fuel economy, you must
always maintain recommended
tire inflation pressures and stay
within the load limits and weight
distribution recommended for your
vehicle.
ODN8H019025L
All specifications (sizes and
pressures) can be found on a label
attached to the driver’s side center
pillar.
Recommended Cold Tire
Inflation Pressures
All tire pressures (including the
spare) should be checked when the
tires are cold. “Cold tires” means the
vehicle has not been driven for at
least three hours or has been driven
for less than one mile (1.6 km).
Warm tires normally exceed
recommended cold tire pressures
by 4 to 6 psi (28 to 41 kPa). Do not
release air from warm tires to adjust
the pressure or the tires will be
under-inflated. For recommended
inflation pressure, refer to “Tire and
Wheels” in chapter 2.
tirES and whEElS

Maintenance
8-46
All Season Tires
HYUNDAI specifies all season
tires on some models to provide
good performance for use all year
round, including snowy and icy
road conditions. All season tires
are identified by ALL SEASON and/
or M+S (Mud and Snow) on the tire
sidewall. Snow tires have better
snow traction than all season tires
and may be more appropriate in
some areas.
Summer Tires
HYUNDAI specifies summer tires on
some models to provide superior
performance on dry roads. Summer
tire performance is substantially
reduced in snow and ice. Summer
tires do not have the tire traction
rating M+S (Mud and Snow) on
the tire side wall. If you plan to
operate your vehicle in snowy or icy
conditions, HYUNDAI recommends
the use of snow tires or all season
tires on all four wheels.
Snow Tires
If you equip your car with snow
tires, they should be the same size
and have the same load capacity as
the original tires. Snow tires should
be installed on all four wheels;
otherwise, poor handling may result.
Snow tires should carry 4 psi (28 kPa)
more air pressure than the pressure
recommended for the standard
tires on the tire label on the driver’s
side of the center pillar, or up to the
maximum pressure shown on the tire
sidewall, whichever is less. Do not
drive faster than 75 mph (120 km/h)
when your vehicle is equipped with
snow tires.
Radial-Ply Tires
Radial-ply tires provide improved
tread life, road hazard resistance
and smoother high speed ride. The
radial-ply tires used on this vehicle
are of belted construction, and are
selected to complement the ride
and handling characteristics of your
vehicle.
Radial-ply tires have the same load
carrying capacity, as bias-ply or
bias belted tires of the same size,
and use the same recommended
inflation pressure. Mixing of radial-
ply tires with bias-ply or bias belted
tires is not recommended. Any
combinations of radial-ply and bias-
ply or bias belted tires when used
on the same vehicle will seriously
deteriorate vehicle handling. The
best rule to follow is: Identical pairs
of radial-ply tires should always be
used as a set for the front tires and a
set for the rear tires.
Longer wearing tires can be more
susceptible to irregular tread wear.
It is very important to follow the tire
rotation interval in this chapter to
achieve the tread life potential of
these tires. Cuts and punctures in
radial-ply tires are repairable only in
the tread area, because of sidewall
flexing. Consult your tire dealer for
radial-ply tire repairs.
WARNING
Do not mix bias ply and radial ply
tires under any circumstances.
This may cause unusual handling
characteristics that may cause loss
of vehicle control resulting in an
accident.