HYUNDAI SONATA 2021 Owners Manual

08
8-17
Engine Coolant
The coolant should be changed at the
intervals specified in the maintenance
schedule.
Automatic Transmission Fluid
Automatic transmission fluid should
not be checked under normal usage
conditions. But in severe conditions, the
fluid should be changed at an authorized
HYUNDAI dealer in accordance to the
scheduled maintenance at the beginning
of this chapter.
Information
Automatic transmission fluid color is red
when new.
As the vehicle is driven, the automatic
transmission fluid will begin to look
darker. This is a normal condition and you
should not judge the need to replace the
fluid based upon the changed color.
NOTICE
The use of a non-specified fluid could
result in transmission malfunction
and failure. Use only the specified
automatic transmission fluid (refer
to “Recommended Lubricants and
Capacities” in chapter 2).
Brake Hoses and Lines
Visually check for proper installation,
chafing, cracks, deterioration and any
leakage. Replace any deteriorated or
damaged parts immediately.
Brake Fluid
Check the brake fluid level in the brake
fluid reservoir. The level should be
between the MIN and the MAX marks
on the side of the reservoir. Use only
hydraulic brake fluid conforming to DOT
4 specification.
Parking Brake
Inspect the parking brake system
including the parking brake pedal and
cables.
Brake Discs, Pads, Calipers and
Rotors
Check the pads for excessive wear, discs
for run out and wear, and calipers for
fluid leakage.
Exhaust Pipe and Muffler
Visually inspect the exhaust pipes,
muffler and hangers for cracks,
deterioration, or damage. Start
the engine and listen carefully for
any exhaust gas leakage. Tighten
connections or replace parts as
necessary.

Maintenance
8-18
Suspension Mounting Bolts
Check the suspension connections for
looseness or damage. Retighten to the
specified torque.
Steering Gear Box, Linkage &
Boots/Lower Arm Ball Joint
With the vehicle stopped and the engine
off, check for excessive freeplay in the
steering wheel. Check the linkage for
bends or damage. Check the dust boots
and ball joints for deterioration, cracks,
or damage.
Replace any damaged parts.
Drive Shafts and Boots
Check the drive shafts, boots and clamps
for cracks, deterioration, or damage.
Replace any damaged parts and, if
necessary, repack the grease.
Air Conditioning Refrigerant
Check the air conditioning lines and
connections for leakage and damage.

08
8-19
Checking the Engine Oil Level
1. Follow all of the oil manufacturer’s precautions.
2.

Be sur
e the vehicle is on the level
ground in P (Park) with the parking
brake set. If possible, block the
wheels.
3.

T
urn the engine on and allow the
engine to reach normal operating
temperature.
4.
T

urn the engine off and wait about
five minutes for the oil to return to the
oil pan.
5.

Pull the dips
tick out, wipe it clean, and
re-insert it fully.
„„Smartstream G1.6 T-GDi
ODN8089104
„„Smartstream G2.5 GDi
ODN8A080107
6. Pull the dips tick out again and check
the level. The level should be between
F and L.
„„Smartstream G1.6 T-GDi
ODN8089105
„„Smartstream G2.5 GDi
ODN8089003
7. If it is near or a t L, add enough oil to
bring the level to F.
Use only the specified engine oil. (refer
to “Recommended Lubricants and
Capacities” 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.
• Do not spill engine oil when adding
or changing engine oil. Use a funnel
to help prevent oil from being spilled
on engine components. Wipe off
spilled oil immediately.
EnginE oil

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
8-21
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.
NOTICE
• When the engine overheats from
low engine coolant, suddenly adding
engine coolant may cause cracks
in the engine. To prevent damage,
add engine coolant slowly in small
quantities.
• Do not drive with no engine coolant.
It may cause water pump failure and
engine seizure, etc.
Checking the Engine Coolant
Level
ODN8089004
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 F and the L marks on the
side of the coolant reservoir when the
engine is cool. If the coolant level is low, add enough
distilled (deionized) water to bring the
level to the F mark, but do not overfill. If
frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
Recommended engine coolant
•
When adding coolant, use only
distilled (deionized) water for your
vehicle and never mix hard water in
the coolant filled at the factory.
• An improper coolant mixture can
result in severe malfunction or engine
damage.
• The engine in your vehicle has
aluminum engine parts and must be
protected by an ethylene-glycol with
phosphate based 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.
EnginE Coolant

Maintenance
8-22
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 and
higher.
WARNING
Make sure the coolant cap is properly
closed after refilling coolant. Otherwise
the engine could be overheated while
driving.
„„Engine room front view
ODN8089052L
1. Check if the c oolant cap label is
straight In front.
2.

M
ake sure that the tiny protrusions
inside the coolant cap is securely
interlocked.
ODN8089044
WARNING
Never remove the engine
coolant reservoir tank/radiator
cap or the drain plug while the
engine and radiator are hot.
Hot coolant and steam may blow out
under pressure, causing serious injury.
Turn the engine off and wait until the
engine cools down. Use extreme care
when removing the engine coolant
reservoir tank/radiator 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.

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
8-25
Checking the Washer Fluid Level
ODN8089006
Check the fluid level in the washer fluid
reservoir and add fluid if necessary. Plain
water may be used 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 flames 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.
waS h E r f luid

Maintenance
8-26
Filter Replacement
The air cleaner filter can be cleaned for
inspection using compressed air.
Do not attempt to wash or to rinse it, as
water will damage the filter.
If soiled, the air cleaner filter must be
replaced.
„„Smartstream G1.6 T-GDi
ODN8089106
„„Smartstream G2.5 GDi
ODN8089007
ODN8089008
ODN8089040
ODN8089041
ODN8089009
air ClEanEr