2021 HYUNDAI NEXO maintenance

5-124
Driving your vehicle
When using tire chains:
Wrong size chains or improperly
installed chains can damage
your vehicle's brake lines, sus-
pension, body and wheels.
Use SAE "S" class or wire
chains.
If you hear noise caused by
chains contacting the body,
retighten the chain to prevent
contact with the vehicle body.
To prevent body damage,
retighten the chains after driving
0.3~0.6 miles (0.5~1.0 km).
Do not use tire chains on vehi-
cles equipped with aluminum
wheels. If unavoidable, use a
wire type chain.
Use wire chains less than 0.47 in
(12 mm) thick to prevent damage
to the chain's connection.
Winter Precautions
Use high quality ethylene glycol
coolant
Your vehicle is delivered with high
quality ethylene glycol coolant in the
cooling system. It is the only type of
coolant that should be used because
it helps prevent corrosion in the cool-
ing system, lubricates the water
pump and prevents freezing. Be sure
to replace or replenish your coolant
in accordance with the maintenance
schedule in chapter 7. Before winter,
have your coolant tested to assure
that its freezing point is sufficient for
the temperatures anticipated during
the winter.
Use approved window washer
anti-freeze in system
To keep the water in the window
washer system from freezing, add an
approved window washer anti-freeze
solution in accordance with instruc-
tions on the container. Window wash-
er anti-freeze is available from an
authorized HYUNDAI dealer and
most auto parts outlets. Do not use
coolant or other types of anti-freeze
as these may damage the paint fin-
ish.
Do not let your parking brake
freeze
Under some conditions your parking
brake can freeze in the engaged
position. This is most likely to happen
when there is an accumulation of
snow or ice around or near the rear
brakes or if the brakes are wet. If
there is a risk the parking brake may
freeze, apply it only temporarily while
you shift to P (Park) and block the
rear wheels so the car cannot roll.
Then release the parking brake.
NOTICE

7
Maintenance
7
Maintenance
Fuel cell power module compartment.................7-3
Maintenance services ...........................................7-4
Owner's Responsibility .....................................................7-4
Owner Maintenance Precautions..................................7-4
Owner maintenance ...............................................7-5
Owner maintenance schedule ........................................7-6
Scheduled maintenance services.........................7-7
Normal Maintenance Schedule ......................................7-8
Maintenance Under Severe Usage Conditions ........7-10
Explanation of scheduled maintenance items .7-12
Device cooling coolant ........................................7-13
Checking the Coolant Level ..........................................7-13
Changing Coolant ............................................................7-15
Stack cooling coolant ..........................................7-16
Checking the Coolant Level ..........................................7-16
Changing Coolant ............................................................7-18
Brake fluid ............................................................7-19
Checking the Brake Fluid Level ...................................7-19
Washer fluid .........................................................7-20
Checking the Washer Fluid Level................................7-20
Air cleaner ............................................................7-20
Filter Replacement ..........................................................7-20
Climate control air filter .....................................7-22
Filter Inspection ...............................................................7-22
Wiper blades .........................................................7-24
Blade Inspection ..............................................................7-24
Blade Replacement .........................................................7-24
12V battery ...........................................................7-27
Battery recharging .........................................................7-28
Reset Features.................................................................7-28
Tires and wheels ..................................................7-29
Tire Care ........................................................................\
....7-29
Recommended Cold Tire Inflation Pressures ...........7-30
Check Tire Inflation Pressure ......................................7-31
Tire Rotation...................................................................\
..7-32
Wheel Alignment and Tire Balance ............................7-33
Tire Replacement ............................................................7-33
Wheel Replacement ........................................................7-34
Tire Traction .....................................................................7-3\
4
Tire Maintenance ............................................................7-34
Tire Sidewall Labeling ....................................................7-34
Tire Terminology and Definitions................................7-38
All Season Tires ...............................................................7-42
Summer Tires ...................................................................7-42
Snow Tires ........................................................................\
7-42
Radial-Ply Tires ...............................................................7-42
Low Aspect Ratio Tires..................................................7-43
7

7-3
7
Maintenance
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1. Brake fluid reservoir
2. Air cleaner
3. Fuse box
4. Windshield washer fluid reservoir
5. Device cooling coolant reservoir
6. Traction motor radiator cap
7. Stack cooling coolant reservoir
8. Fuel cell stack radiator cap
OFE078001
The actual fuel cell power module compartment in the vehicle may differ from the illus-
tration.

7-4
Maintenance
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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 Owner's Handbook &
Warranty Information booklet.
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 for
the 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.
Certain modifications may also be in
violation of regulations established
by the U.S. Department of
Transportation and other federal or
state agencies.
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 Owner's
Handbook & Warranty Information
booklet provided with the vehicle.
If you're unsure about any service
or maintenance procedure, have it
done by an authorized HYUNDAI
dealer.The following lists are vehicle checks
and 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 proper
tools 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
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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, level
road.
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

7-7
7
Maintenance
At least once a year:
Clean body and door drain holes.
Lubricate door hinges and hoodhinges.
Lubricate door and hood locks and latches.
Lubricate door rubber weather strips.
Lubricate door checker.
Check the air conditioning system.
Inspect and lubricate reduction gear linkage and controls.
Check the brake fluid level.
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Follow Normal Maintenance Schedule if the vehicle is usually operated where
none of the following conditions apply. If any of the following conditions apply,
you must follow the Maintenance Under Severe Usage Conditions.
Repeated driving short distance of less than 8 km (5 miles) in normal tem-
perature or less than 16 km (10 miles) in freezing temperature
Low speed driving for long distances
Driving on rough, dusty, muddy, unpaved, graveled or salt-spread roads
Driving in areas using salt or other corrosive materials or in very cold weather
Driving in heavy dust condition
Driving in heavy traffic area
Driving on uphill, downhill, or mountain road repeatedly
Towing a trailer or using a camper, or roof rack
Driving as a patrol car, taxi, other commercial use of vehicle towing
Driving over 170 km/h (106 miles/h)
Frequently driving in stop-and-go condition
If your vehicle is operated under the above conditions, you should inspect, replace or refill more frequently than the following Normal MaintenanceSchedule. After the periods or distance shown in the chart, continue to followthe prescribed maintenance intervals.

7-8
Maintenance
Normal Maintenance Schedule
Months1224364860728496108120132144156168180
Miles×1,00061218243036424854606672788490
Km×1,000102030405060708090100110120130140150
Hydrogen system
(Check the hydrogen leakage)Inspect every 6,000 miles (10,000 km) or 24 months
Air cleaner filterReplace every at 12,000 (20,000 km) miles
Device cooling coolantAt first, replace at 120,000 miles (200,000 km) or 10 years :
Thereafter, replace every 30,000 miles (48,000 km) or 24 months
Stack cooling coolantReplace every at 36,000 miles (60,000 km) or 36 months
Ion filterReplace every at 36,000 miles (60,000 km) or 36 months
Reduction gearNo check, No service required
Air conditioner refrigerant/
compressorIIIIIIIIIIIIIII
Brake lines, hoses and connectionsIIIIIIIIIIIIIII
Brake discs and padsIIIIIIIIIIIIIII
Driveshaft and bootsIIIIIII
Front suspension ball jointsIIIIIIIIIIIIIII
Maintenance Intervals
Maintenance
Item
I : Inspect and if necessary, adjust, correct, clean or replace.
R : Replace