2015 Hyundai Sonata Hybrid Owner's Manual

Maintenance
20
7
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.
Valve clearance
Inspect excessive valve noise and/or
engine vibration and adjust if necessary.
An authorized HYUNDAI dealer should
perform the operation.
Cooling system
Check cooling system components, such
as radiator, coolant reservoir, hoses and
connections for leakage and damage.
Replace any damaged parts.
Coolant
The engine and inverter coolants should
be changed at the intervals specified in
the maintenance schedule.
Automatic transaxle fluid
Automatic transaxle 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.
✽ ✽
NOTICE
Automatic transaxle fluid color is basi-
cally red.
As the vehicle is driven, the automatic
transaxle 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.
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 brake fluid level in the brake fluid
reservoir. The level should be between
“MIN” and “MAX” marks on the side of
the reservoir. Use only hydraulic brake
fluid conforming to DOT 3 or DOT 4
specification.
CAUTION
The use of a non-specified fluid
could result in transaxle malfunc-tion and failure.
Use only specified automatictransaxle fluid. (Refer to“Recommended lubricants andcapacities” in section 8.)

721
Maintenance
Parking brake
Inspect the parking brake system includ-
ing 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, muf-
fler 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.
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 engine off,
check for excessive free-play 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 nec-
essary, repack the grease.
Air conditioning refrigerant
Check the air conditioning lines and con-
nections for leakage and damage.

Maintenance
22
7
ENGINE OIL
WARNING - Radiator hose
Be very careful not to touch the
radiator hose when checking or
adding the engine oil as it may be
hot enough to burn you.
CAUTION
Do not overfill with engine oil.
Engine damage may result.
Checking the engine oil level
1. Be sure the vehicle is on level ground.
2. Start the engine and allow it to reach normal operating temperature.
3. Turn the engine off and wait for a few minutes (about 5 minutes) for the oil to
return to the oil pan.
4. Pull the dipstick out, wipe it clean, and re-insert it fully. 5. Pull the dipstick out again and check
the level. The level should be between
F and L.
If it is near or at L, add enough oil to bring
the level to F.Do not overfill.
Use a funnel to help prevent oil from
being spilled on engine components.
Use only the specified engine oil. (Refer to “Recommended lubricants and capaci- ties” in section 8.)
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CAUTION
Do not spill engine oil, when addingor changing engine oil. If you spillengine oil on the engine room, wipeit off immediately.

723
Maintenance
Changing the engine oil and filter
Have engine oil and filter changed by an
authorized HYUNDAI dealer according to
the Maintenance Schedule at the begin-
ning of this section.
CALIFORNIA PROPOSI-
TION 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 irrita-
tion or cancer of the skin if left in
contact with the skin for prolonged
periods of time. Used engine oil
contains chemicals that have
caused cancer in laboratory ani-
mals. Always protect your skin by
washing your hands thoroughly
with soap and warm water as soon
as possible after handling used oil.

Maintenance
24
7
COOLANT
Inverter coolant
The high-pressure cooling system has a
reservoir filled with year-round antifreeze
coolant. The reservoir is filled at the fac-
tory.
Check the antifreeze protection and
coolant level. If it is near or at MIN, add enough coolant
between MIN and MAX and check the
cooling system for air bleed at an author-
ized HYUNDAI dealer.
Engine coolant
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 per every day, at the begin-
ning of the winter season, and before
traveling to a colder climate.
Checking the coolant level
CAUTION
Do not mix-up the caps of engine
coolant and inverter coolant.
If mixed-up it could create a coolantcirculation problem for the engineor Hybrid system.
CAUTION
When adding coolant, be carefulnot to overfill.
WARNING
Removing radiator
and inverter coolant
cap
Never attempt to remove the radi- ator and/or inverter coolant cap
while the engine is operating or
hot. Doing so might lead to cool-
ing system and engine damage
and could result in serious per-
sonal injury from escaping hot
coolant or steam.
(Continued)
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725
Maintenance
Check the condition and connections of
all cooling system hoses and heater
hoses. Replace any swollen or deterio-
rated hoses.
The coolant level should be filled
between F and 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 provide pro-
tection against freezing and corrosion.
Bring the level to F, but do not overfill. If
frequent additions are required, see an
authorized HYUNDAI dealer for a cooling
system inspection.
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(Continued)
The engine coolant and/or invertercoolant level is influenced by
hybrid system temperature. Before
filling the engine coolant and/or
inverter coolant, turn the hybrid
vehicle off, fill the engine coolant
and/or inverter coolant carefully.
Turn the engine off and wait until it cools down. Use extreme care
when removing the radiator and/or
inverter coolant cap. Wrap a thick
towel around it, and turn it coun-
terclockwise slowly to the first
stop. Step back while the pressure
is released from the cooling sys-
tem. When you are sure all the
pressure has been released, press
down on the cap, using a thick
towel, and continue turning coun-
terclockwise to remove it.
Even if the engine is not operat- ing, do not remove the radiator
and/or inverter coolant cap or the
drain plug while the engine and
radiator are hot. Hot coolant and
steam may still blow out under
pressure, causing serious injury.WARNING
The electric motor
(cooling fan) is con-
trolled by engine
coolant temperature,
refrigerant pressure
and vehicle speed. It may some-
times operate even when the
engine is not running. Use extreme
caution when working near the
blades of the cooling fan so that
you are not injured by the rotating
fan blades. As the engine coolant
temperature decreases, the electric
motor will automatically shut off.
This is a normal condition.

Maintenance
26
7
Recommended engine and inverter
coolant
When adding coolant, use only deion- ized water or soft water for your vehicle
and never mix hard water in the
coolant filled at the factory. An improp-
er coolant mixture can result in serious
malfunction or engine damage.
The engine in your vehicle has aluminum engine parts and must be protected by
an ethylene-glycol-based coolant to pre-
vent 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 mixture percentage, refer to the fol-
lowing table.
Changing the coolant
Have engine and inverter coolant
changed by an authorized HYUNDAI
dealer according to the Maintenance
Schedule at the beginning of this section.
WARNING - Radiator cap &
Inverter coolant cap
Do not remove the radiator cap and
/or inverter coolant cap when the
engine and radiator are hot.
Scalding hot coolant and steam
may blow out under pressure caus-
ing serious injury.
WARNING -Coolant
Do not use radiator coolant or
antifreeze in the washer fluid
reservoir.
Radiator coolant can severely obscure visibility when sprayed
on the windshield and may cause
loss of vehicle control or damage
to paint and body trim.
CAUTION
Put a thick cloth or fabric aroundthe radiator and/or inverter cap before refilling the coolant in orderto prevent the coolant from over- flowing into engine parts such asthe generator.
5°F (-15°C) 35 65
-13°F (-25°C) 40 60
-31°F (-35°C) 50 50
-49°F (-45°C) 60 40
Ambient
Temperature Mixture Percentage (volume)
Antifreeze Water
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Radiator cap
Inverter coolant cap

727
Maintenance
BRAKE FLUID
Checking the brake fluid level
Check the fluid level in the reservoir peri-
odically. The fluid level should be
between MAX and MIN marks on the
side of the reservoir. To check the brake
fluid exactly, after stopping the vehicle,
apply the brake pedal a few times and
then check the fluid level.
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 fluid to the MAX
level. The level will fall with accumulated
mileage. This is a normal condition asso-
ciated with the wear of the brake linings.
If the fluid level is excessively low, have
the brake system checked by an author-
ized HYUNDAI dealer.
Use only the specified brake fluid. (Referto “Recommended lubricants or capaci-ties” in section 8.)
Never mix different types of fluid.
WARNING - Brake fluid
When changing and adding brake
fluid, handle it carefully. Do not let it
come in contact with your eyes. If
brake fluid should come in contact
with your eyes, immediately flush
them with a large quantity of fresh
tap water. Have your eyes examined
by a doctor as soon as possible.
WARNING - Loss of brake
fluid
In the event the brake system
requires frequent additions of fluid,
the vehicle should be inspected by
an authorized HYUNDAI dealer.CAUTION
Do not allow brake fluid to contactthe vehicle's body paint, as paintdamage will result. Brake fluid,which has been exposed to open air for an extended time should neverbe used as its quality cannot be guaranteed. It should be disposedof properly. Don't put in the wrongkind of fluid. A few drops of miner- al-based oil, such as engine oil, inyour brake system can damage brake system parts.
CAUTION
Do not overfill the brake fluid. Brakesystem damage may occur if thebrake fluid level exceeds the Max fill level.
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