2023 HYUNDAI NEXO coolant reservoir

1-6
Your vehicle at a glanceF
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1. Brake fluid reservoir ..........................7-19
2. Air cleaner.........................................7-20
3. Fuse box ...........................................7-53
4. Windshield washer fluid reservoir .....7-20
5. Device cooling coolant reservoir .......7-13
6. Device cooling radiator cap ..............7-14
7. Stack cooling coolant reservoir.........7-16
8. Stack cooling radiator cap ................7-17
OFE078001
The actual Fuel cell power module compartment in the vehicle may differ from the illustration.

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Convenient features of your vehicle
3
- Fuel Cell StackOverheats
If the gauge pointer moves
beyond the normal range area
toward the "H" position, it indi-
cates overheating that may dam-
age the fuel cell stack.Hydrogen fuel gauge
This gauge indicates the approxi-mate amount of fuel remaining in thefuel tank (The fuel tank capacity is
given in chapter 8). The fuel gauge is
supplemented by a low fuel warninglight which will illuminate when the
fuel tank is nearly empty. Information -
HydrogenFueling Station
According to the hydrogen fueling sta-
tion condition, the hydrogen fuel may
not filled fully.i
NOTICE
Running Out of Fuel
Running out of fuel can expose
vehicle occupants to danger.
You must stop and obtain addi-
tional fuel as soon as possibleafter the warning light comes
on or when the gauge indicator
comes close to the ''E'' (Empty)
level.
WARNING
Radiator Cap
Never remove the radiator cap
when the fuel cell power mod-
ule is hot. Otherwise the fuel
cell stack coolant may be under
pressure and cause severe
burns. Wait until the fuel cell
power module is cool before
adding coolant to the reservoir.
WARNING
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6. If you cannot find the cause of the
overheating, wait until the radiator
temperature has returned to nor-
mal. Then, if coolant has beenlost, carefully add coolant to the
reservoir to bring the fluid level in
the reservoir up to the halfway
mark.
7. Proceed with caution, keeping alert for further signs of overheat-
ing. If overheating happens again,
call an authorized HYUNDAI deal-
er for assistance.
What to do in an emergency
Serious loss of coolant indi- cates a leak in the cooling sys-
tem and should be checked as
soon as possible by an author-
ized HYUNDAI dealer.
CAUTION

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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.

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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

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MaintenanceE
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Cooling System
Check cooling system components,
such as radiator, coolant reservoir,
hoses and connections for leakage
and damage. Replace any damaged
parts.
Coolant
The coolant should be changed at
the intervals specified in the mainte-
nance schedule.
Reduction Gear Fluid
Inspect the reduction gear fluid according to the maintenance sched-
ule.
Brake Hoses and Lines
Visually check for proper installation,
chafing, cracks, deterioration and
any leakage. Replace any deteriorat-
ed or damaged parts immediately.
Brake Fluid
Check 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 con-
forming to DOT 3 or DOT 4 specifi-cation.
Brake Discs, Pads, Calipers
and Rotors
Check the pads for excessive wear,
discs for run out and wear, and
calipers for fluid leakage.
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
vehicle 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 necessary, repack the
grease.
Air Conditioning Refrigerant
Check the air conditioning lines and
connections for leakage and dam-
age.

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7
Maintenance
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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, atthe beginning of the winter season
and before traveling to a colder cli-
mate.Checking the Coolant Level
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 MAX and the MIN
marks on the rear side of the coolant
reservoir when the parts in the fuel
cell power module compartment iscool.
If the coolant level is low, add enough
distilled (deionized) water to bring
the level to the MAX mark, but do not
overfill. If frequent additions are
required, you see an authorized
HYUNDAI dealer for a cooling sys-tem inspection.
Recommended 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
electric devices damage.
Do not use alcohol or methanol coolant or mix them with the spec-ified coolant.
Do not use a solution that contains more than 60% antifreeze or less
than 35% antifreeze, which would
reduce the effectiveness of thesolution.
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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