Protection HYUNDAI SONATA 2021 Owner's Manual

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

08
8-31
WARNING
To prevent SERIOUS INJURY or DEATH
to you or bystanders, always follow
these precautions when working near
or handling the battery:
Always read and follow
instructions carefully when
handling a battery.
Wear eye protection designed
to protect the eyes from acid
splashes.
Keep all flames, sparks, or
smoking materials away from
the battery.
Hydrogen is always present
in battery cells, is highly
combustible, and may explode
if ignited.
Keep batteries out of reach of
children.
Batteries contain sulfuric acid
which is highly corrosive. Do
not allow acid to contact your
eyes, skin or clothing.
If acid gets into your eyes, flush your
eyes with clean water for at least 15
minutes and get immediate medical
attention. If acid gets on your skin,
thoroughly wash the area. If you feel
pain or a burning sensation, get medical
attention immediately.
• When lifting a plastic-cased battery,
excessive pressure on the case may
cause battery acid to leak. Lift with a
battery carrier or with your hands on
opposite corners.
• Do not attempt to jump start your
vehicle if your battery is frozen.
• NEVER attempt to recharge the
battery when the vehicle’s battery
cables are connected to the battery.
• The electrical ignition system works
with high voltage. NEVER touch
these components with the engine
running or when the ignition switch
is in the ON position.
WARNING
CALIFORNIA PROPOSITION 65
WARNING
Battery posts, terminals, and related
accessories contain lead and lead
compounds, chemicals known to the
State of California to cause cancer,
birth defects and reproductive harm.
Batteries also contain other chemicals
known to the State of California
to cause cancer. Wash hands after
handling.
NOTICE
• When you do not use the vehicle for a
long time in a low temperature area,
disconnect the battery and keep it
indoors.
• Always charge the battery fully to
prevent battery case damage in low
temperature areas.
BattEry

Maintenance
8-32
For Best Battery Service
ODN8089014
• Keep the battery securely mounted.
• Keep the battery top clean and dry.
• Keep the terminals and connections
clean, tight, and coated with
petroleum jelly or terminal grease.
• Rinse any spilled acid from the battery
immediately with a solution of water
and baking soda.
Battery Recharging
WARNING
Always follow these instructions when
recharging your vehicle’s battery to
avoid the risk of SERIOUS INJURY or
DEATH from explosions or acid burns:
• Before performing maintenance or
recharging the battery, turn off all
accessories and place the ignition
switch to the LOCK/OFF position.
• Keep all flames, sparks, or smoking
materials away from the battery.
• Always work outdoors or in an area
with plenty of ventilation.
• Wear eye protection when checking
the battery during charging.
• The battery must be removed from
the vehicle and placed in a well
ventilated area.
• Watch the battery during charging,
and stop or reduce the charging
rate if the battery cells begin boiling
violently.
• Vehicle is equipped with the
Absorbent Glass Mat (AGM) battery.
Do not charge the AGM battery with
a general charger. It may damage
or explode the AGM battery. Only
charge the AGM battery with a
charger that has AGM battery
setting.

08
8-65
Repairing your vehicle’s finish
Deep scratches or stone chips in the
painted surface must be repaired
promptly. Exposed metal will quickly
rust and may develop into a major repair
expense.
NOTICE
If your vehicle is damaged and requires
any metal repair or replacement,
be sure the body shop applies anti-
corrosion materials to the parts
repaired or replaced.
NOTICE
Matte paint finish vehicle (if equipped)
In case of matte paint finish vehicles,
it is impossible to modify only the
damaged area and repair of the whole
part is necessary. If the vehicle is
damaged and painting is required,
we recommend that you have your
vehicle maintained and repaired by
an authorized HYUNDAI dealer. Take
extreme care, as it is difficult to restore
the quality after the repair.
Bright-metal maintenance
• To remove road tar and insects, use
a tar remover, not a scraper or other
sharp object.
• To protect the surfaces of bright metal
parts from corrosion, apply a coating
of wax or chrome preservative and rub
to a high luster.
• During winter weather or in coastal
areas, cover the bright metal parts
with a heavier coating of wax or
preservative. If necessary, coat the
parts with non-corrosive petroleum
jelly or other protective compound.
Underbody maintenance
Corrosive materials used for ice and
snow removal and dust control may
collect on the underbody. If these
materials are not removed, accelerated
rusting can occur on underbody parts
such as the fuel lines, frame, floor pan
and exhaust system, even though they
have been treated with rust protection.
Thoroughly flush the vehicle underbody
and wheel openings with lukewarm or
cold water once a month, after off-road
driving and at the end of each winter. Pay
special attention to these areas because
it is difficult to see all the mud and dirt.
It will do more harm than good to wet
down the road grime without removing
it. The lower edges of doors, rocker
panels, and frame members have drain
holes that should not be allowed to clog
with dirt; trapped water in these areas
can cause rusting.
WARNING
After washing the vehicle, test the
brakes while driving slowly to see if
they have been affected by water. If
braking performance is impaired, dry
the brakes by applying them lightly
while maintaining a slow forward
speed.
Aluminum wheel maintenance
The aluminum wheels are coated with a
clear protective finish.

Maintenance
8-66
NOTICE
•Do not use abrasive cleaner,
polishing compound, solvent, or wire
brushes on aluminum wheels.
• Clean the wheel when it has cooled.
• Use only a mild soap or neutral
detergent, and rinse thoroughly with
water. Also, clean the wheels after
driving on salted roads.
• Do not wash the wheels with high-
speed car wash brushes.
• Do not use any cleaners containing
acid or alkaline detergents.
Corrosion protection
Protecting your vehicle from corrosion
By using the most advanced design
and construction practices to combat
corrosion, HYUNDAI produces vehicles
of the highest quality. However, this is
only part of the job. To achieve the long-
term corrosion resistance your vehicle
can deliver, the owner’s cooperation and
assistance is also required.
Common causes of corrosion
The most common causes of corrosion
on your vehicle are:
•Road salt, dirt and moisture that is
allowed to accumulate underneath
the vehicle.
• Removal of paint or protective
coatings by stones, gravel, abrasion
or minor scrapes and dents which
leave unprotected metal exposed to
corrosion.
High-corrosion areas
If you live in an area where your vehicle is
regularly exposed to corrosive materials,
corrosion protection is particularly
important. Some of the common causes
of accelerated corrosion are road salts,
dust control chemicals, ocean air and
industrial pollution. Moisture breeds corrosion
Moisture creates the conditions in
which corrosion is most likely to occur.
For example, corrosion is accelerated
by high humidity, particularly when
temperatures are just above freezing. In
such conditions, the corrosive material is
kept in contact with the car surfaces by
moisture that is slow to evaporate.
Mud is particularly corrosive because it is
slow to dry and holds moisture in contact
with the vehicle. Although the mud
appears to be dry, it can still retain the
moisture and promote corrosion.
High temperatures can also accelerate
corrosion of parts that are not properly
ventilated so the moisture can be
dispersed. For all these reasons, it is
particularly important to keep your
vehicle clean and free of mud or
accumulations of other materials. This
applies not only to the visible surfaces
but particularly to the underside of the
vehicle.
To help prevent corrosion
Keep your vehicle clean
The best way to prevent corrosion is
to keep your vehicle clean and free of
corrosive materials. Attention to the
underside of the vehicle is particularly
important.
•
If you live in a high-corrosion area —
where road salts are used, near the
ocean, areas with industrial pollution,
acid rain, etc.—, you should take extra
care to prevent corrosion. In winter,
hose off the underside of your vehicle
at least once a month and be sure to
clean the underside thoroughly when
winter is over.
•