2023 HYUNDAI NEXO warning

7-4
MaintenanceM
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You should exercise the utmost care
to prevent damage to your vehicle
and injury to yourself whenever per-
forming any maintenance or inspec-
tion procedures.
We recommend you have your vehi-
cle maintained and repaired by an
authorized HYUNDAI dealer. An
authorized HYUNDAI dealer meets
HYUNDAI's high service quality
standards and receives technical
support from HYUNDAI in order to
provide you with a high level of serv-
ice satisfaction.Owner's Responsibility
Maintenance service and record
retention are the owner's responsibil-
ity.
You should retain documents that
show proper maintenance has been
performed on your vehicle in accor-dance with the scheduled mainte-
nance service charts shown on the
following pages. You need this infor-
mation to establish your compliance
with the servicing and maintenance
requirements of your vehicle war-
ranties.
Detailed warranty information is pro-
vided in your Service Passport. Repairs and adjustments required as a result of improper maintenance or
a lack of required maintenance are
not covered.
Owner Maintenance Precautions
Inadequate, incomplete or insuffi-
cient servicing may result in opera-
tional problems with your vehicle that
could lead to vehicle damage, an
accident, or personal injury. This
chapter provides instructions only forthe maintenance items that are easy
to perform. Several procedures can
be done only by an authorized
HYUNDAI dealer with special tools.
Your vehicle should not be modified
in any way. Such modifications may
adversely affect the performance,
safety or durability of your vehicle
and may, in addition, violate condi-
tions of the limited warranties cover-
ing the vehicle.
High voltage caution
Do not disassemble or perform maintenance on the fuel cell
system unless you are quali-
fied. The fuel cell system can be
highly dangerous since there
are many high voltage parts
inside even if when power is off.
WARNING

7-5
7
Maintenance
Improper owner maintenance dur-
ing the warranty period may affect
warranty coverage. For details,
read the separate Service
Passport provided with the vehi-
cle. If you're unsure about any
service or maintenance proce-
dure, have it done by an author-
ized HYUNDAI dealer.The following lists are vehicle checksand inspections that should be per-
formed by the owner or an author-
ized HYUNDAI dealer at the frequen-
cies indicated to help ensure safe,
dependable operation of your vehi-
cle.
Any adverse conditions should be
brought to the attention of your deal-
er as soon as possible.
These Owner Maintenance vehicle
checks are generally not covered by
warranties and you may be charged
for labor, parts and lubricants used.
NOTICE
Performing maintenance work
on a vehicle can be dangerous.
If you lack sufficient knowledge
and experience or the propertools and equipment to do the
work, have it done by an author-
ized HYUNDAI dealer.
ALWAYS follow these precau-
tions for performing mainte-
nance work:
•Park your vehicle on level
ground, shift to the P (Park)
position, apply the parking
brake, and place the POWER
button in the OFF position.
Block the tires (front and
back) to prevent the vehicle
from moving.
Remove loose clothing or jew-
elry that can become entan-
gled in moving parts.
Keep flames, sparks, or smok-
ing materials away from the
battery related parts.
WARNING
OO
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7-6
Maintenance
Owner Maintenance Schedule
When you stop for fuel:
• Check for both fuel cell stack andDevice cooling coolant level in
coolant reservoir.
Check the windshield washer fluid level.
Look for low or under-inflated tires.
While operating your vehicle:
Check for vibrations in the steering wheel. Notice if there is any
increased steering effort or loose-
ness in the steering wheel, or
change in its straight-ahead posi-tion.
Notice if your vehicle constantly turns slightly or "pulls" to one side
when traveling on smooth, levelroad.
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 reduction gear
occurs, check the reduction gear
fluid level.
Check the reduction gear 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 coolantreservoir.
Check the operation of all exterior lights, including the brake lights,
turn signals and hazard warning
flashers.
Check the inflation pressures of all tires that are worn, show uneven
wear, or are damaged.
Check for loose wheel lug nuts.
At least twice a year: (i.e., every Spring and Fall)
Check radiator, heater and air con- ditioning hoses for leaks or dam-
age.
Check windshield washer spray and wiper operation. Clean wiper
blades with clean cloth dampened
with washer fluid.
Check headlamp alignment.
Check the seat belts for wear and function.
Be careful when checking the
coolant level when the fuel cell
power module is hot. Scalding
hot coolant and steam may
blow out under pressure. This
could cause burns or other seri-
ous injury.
WARNING

7-14
Maintenance
For mixing percentage, refer to the
following table: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
-35°C (-31°F) and higher.
i
Ambient
Temperature Mixture Percentage
(volume)
Antifreeze Water
-15°C (5°F) 35 65
-25°C (-13°F) 40 60
-35°C (-31°F) 50 50
-45°C (-49°F) 60 40
Never remove the
radiator cap or the drain plug while the
radiator is hot. Hotcoolant and steam
may blow out under pressure,
causing serious injury.
WARNING
OFE078004 Turn the vehicle off and wait
until the parts in the fuel cell
power module compartment
cools down. Use extreme care
when removing the 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 sys-
tem. When you are sure all thepressure has been released,
press down on the cap, using a
thick towel, and continue turn-
ing counterclockwise to removeit.

7-15
7
MaintenanceThe electric motor for the cooling fan
is controlled by coolant temperature,
refrigerant pressure and vehicle
speed. As the coolant temperature
decreases, the electric motor will
automatically shut off. This is a nor-mal condition.
Changing Coolant
Have coolant changed by an author-
ized HYUNDAI dealer according tothe Maintenance Schedule at the
beginning of this chapter.To prevent damage to parts in the
fuel cell power module compart-
ment, put a thick towel around the
coolant cap before refilling the
coolant to prevent the coolant
from overflowing into parts in the
fuel cell power module compart-ment.
NOTICE
The electric motor for
the cooling fan may
continue to operate
or start up when the
vehicle is not running
and can cause serious injury.
Keep hands, clothing and tools
away from the rotating fan
blades of the cooling fan.
WARNING
Do not use coolant or antifreeze
in the washer fluid reservoir.
Coolant can severely obscure
visibility when sprayed on the
windshield and may cause loss
of vehicle control resulting in anaccident.
Coolant may also cause dam-
age to paint and body trim.
WARNING

Stack cooling coolant
When adding stack coolingcoolant, use only exclusive coolant
for fuel cell stack in authorized
HYUNDAI dealer and never mix
any water or liquid.
An improper coolant mixture can result in severe malfunction or
electric devices damage.
If the vehicle is damaged by adding unspecified liquid except exclusive
coolant for fuel cell stack, it will not
be covered by the warranty.
7-17
7
Maintenance
Never remove the
radiator cap or the drain plug while the
radiator is hot. Hotcoolant and steam
may blow out under pressure,
causing serious injury.
WARNING
OFE078006 Turn the vehicle off and wait
until the parts in the fuel cell
power module compartment
cools down. Use extreme care
when removing the 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 aresure all the pressure has been
released, press down on the
cap, using a thick towel, and
continue turning counterclock-
wise to remove it.

The electric motor for the cooling fan
is controlled by coolant temperature,
refrigerant pressure and vehicle
speed. As the coolant temperature
decreases, the electric motor will
automatically shut off. This is a nor-mal condition.
Changing Coolant
For the fuel cell stack, an exclusive
coolant must be used . When chang-
ing the fuel cell stack coolant, werecommend that coolant be changed
by an authorized HYUNDAI dealeraccording to the MaintenanceSchedule at the beginning of this
chapter.To prevent damage to parts in the
fuel cell power module compart-
ment, put a thick towel around the
coolant cap before refilling the
coolant to prevent the coolant
from overflowing into parts in the
fuel cell power module compart-ment.
NOTICE
7-18
Maintenance
The electric motor for
the cooling fan may
continue to operate
or start up when the
vehicle is not running
and can cause serious injury.
Keep hands, clothing and tools
away from the rotating fan
blades of the cooling fan.
WARNING
Do not use coolant or antifreeze
in the washer fluid reservoir.
Coolant can severely obscure
visibility when sprayed on the
windshield and may cause loss
of vehicle control resulting in anaccident.
Coolant may also cause dam-
age to paint and body trim.
WARNING
Do not mix-up the caps of
device cooling coolant and
stack cooling coolant because
the fluid material is different. If
the cap is mixed, the fuel cell
system may be damage.
We recommend that you con-
sult an authorized HYUNDAI
dealer.
CAUTION

7-19
7
Maintenance
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Checking the Brake Fluid
Level
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 thor-
oughly to prevent brake fluid contam-ination. 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.
Do not allow brake fluid to con-
tact 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 beused as its quality cannot be
guaranteed. It should be dis-
posed of properly.
Do not use the wrong kind of brake fluid. A few drops of min-
eral 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 8).
i
NOTICE
If the brake system requires fre-
quent additions of fluid thiscould 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. Ifbrake fluid comes in contact
with your eyes, flush your eyes
with clean water for at least 15
minutes and get immediatemedical attention.
WARNING
OFE078007