2020 HYUNDAI NEXO brake fluid

7-10
Maintenance
Maintenance Under Severe Usage Conditions
The following items must be serviced more frequently on cars normally used under severe driving conditions. Refer
to the chart below for the appropriate maintenance intervals.
R : Replace I : Inspect and, after inspection, clean, adjust, repair or replace if neces\
sary
Maintenance itemMaintenanceoperationMaintenance intervalsDriving condition
Hydrogen system
(Check the hydrogen leakage)IInspect more frequently
depending on the conditionC, D, F, G, J, L
Air cleaner filterIInspect more frequently
depending on the conditionC, D, E
Device cooling coolantRReplace more frequently
depending on the conditionC, D, E, F, J, K, L
Stack cooling coolantRReplace more frequently
depending on the conditionC, D, F, G, L
Ion filterRReplace more frequently
depending on the conditionC, D, F, G, L
Reduction gear fluidR72,000 miles (120,000 km)C, F, G, I, J
Air conditioner refrigerant/compressorIInspect more frequently
depending on the conditionC, D, F, G, L
Disc brakes and pads, calipers and rotorsIInspect more frequently
depending on the conditionC, D, E, G, H

7-12
Maintenance
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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.

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 be
used 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 this
could 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. If
brake fluid comes in contact
with your eyes, flush your eyes
with clean water for at least 15
minutes and get immediate
medical attention.
WARNING
OFE078007

8-6
Specifications, Consumer information and Reporting safety defects
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To help achieve proper vehicle performance and durability, use only lubricants of the proper quality.
These lubricants and fluids are recommended for use in your vehicle.
Lubricant Volume Classification
Reduction gear fluid1.06 US qt (1 l)
GL4 75W/85, TGO-9
CoolantFuel cell stack
We recommend that you consult an authorized Hyundai dealer.
Traction motor
Brake fluid Amount requiredSAE J1704 DOT-4LV,
FMVSS116 DOT-4,
ISO4925 CLASS-6
Fuel165.48 US qt. (156.6 l)
Hydrogen (SAE J2719 or ISO 14687-2)

H15
Warning and indicator lights
OFE048100N
1. Power gauge
2. Speedometer
3. Fuel cell stack temperature gauge
4. Fuel gauge
5. Odometer/LCD display/Trip computer
6. Warning and indicator lights
Air bag warningCharging system warningElectronic Stability Control
(ESC) OFF indicator Forward Collision-
Avoidance Assist (FCA)
system warning
Seat belt warningLow fuel level warning Immobilizer Indicator
Parking brake &
brake fluid warningLow tire pressure warningTurn Signal IndicatorEPBElectronic Parking Brake
(EPB) warning
Regenerative brake
warningService warning High Beam IndicatorAUTO
HOLDAUTO HOLD Indicator
Anti-lock brake system
(ABS) warningPower down warning Light ON IndicatorMaster Warning
Electronic Brake force
Distribution (EBD) warning
Hydrogen gas leak
warning (Red) Ready indicatorLED Headlamp warning
Hydrogen leak sensor
warning (Yellow)Lane Keeping Assist (LKA)
system indicator
Electric Power Steering
(EPS) warningElectronic Stability Control
(ESC) indicator
Yellow
❈For more details, refer to the ‘Instrument cluster’ in Chapter 3.

H35
CategoryQuestionsAnswers
Vehicle
Management
(12 items)
19. What are the do-it-yourself (DIY) main-
tenance items for the FCEV?
DIY Check: Device cooling coolant, Stack cooling coolant, Brake
Fluid, Tire and Wheels
DIY Maintenance: Washer fluid, Air cleaner, Climate control air filter,
Wiper blades, Fuse, Light bulb
20. What should I be aware of when doing
DIY maintenance work?Be careful not to touch the high-voltage cable (orange color),
coolant, and ion filter.
21. Tell me what the potential effects are of
parking long-term in a cold area (-4 °F
(-20 °C)) for the FCEV, and whether or
not the vehicle can startup under such
conditions.In most instances, the vehicle can get startup in cold weather with-
out any problems. However, the vehicle may not start if it is parked
with the power off for over a week in cold temperatures. In this case,
If you will not be turning on the vehicle for more than a week in cold
weather, it is recommended that you park the vehicle inside a build-
ing, if possible.
22. What parts must I not touch with
hands? For example, high-voltage
cable, ion filter, etc.?
High-voltage cable (orange color), ion filter, parts with a high voltage
warning sticker.
Also, never touch the hydrogen storage system under the liftgate,
the hydrogen supply pipe under the vehicle and the hydrogen supply
system components on the right side (based on the driver’s position)
of the hood.

I-3
Blind-Spot View Monitor System ..................................5-77
Operating conditions ..................................................5-77
Blind-Spot View Monitor system warning ................5-78
Brake fluid ......................................................................7-19
Checking the Brake Fluid Level ................................7-19
Braking System ...............................................................5-18
Power Brakes..............................................................5-18
Disc Brake Wear Indicator .........................................5-19
Electronic Parking Brake (EPB) ................................5-19
Auto Hold ...................................................................5-25
Anti-lock Brake System (ABS)..................................5-29
Electronic Stability Control (ESC).............................5-31
Vehicle Stability Management (VSM) .......................5-34
Hill-Start Assist Control (HAC) .................................5-36
Good Braking Practices..............................................5-36
Bulb Wattage .....................................................................8-3
California perchlorate notice ..........................................7-70
Cargo Security Screen ..................................................3-174
Center Console Storage ................................................3-163
Child Restraint System (CRS) ........................................2-36
Children Always in the Rear ......................................2-36
Selecting a Child Restraint System (CRS).................2-37
Installing a Child Restraint System (CRS) ................2-39
Child-Protector Rear Door Locks ...................................3-18Climate Control Additional Features ............................3-162
Automatic Ventilation...............................................3-162
Sunroof Inside Air Recirculation .............................3-162
Climate control air filter .................................................7-22
Filter Inspection..........................................................7-22
Clock .............................................................................3-171
Coat Hook .....................................................................3-172
Consumer Information ......................................................8-9
Cup Holder....................................................................3-164
Customer Q&A Guide (FCEV) .......................................H30
Device cooling coolant ...................................................7-13
Checking the Coolant Level .......................................7-13
Changing Coolant.......................................................7-15
Dimensions .......................................................................8-2
Disc Brake Wear Indicator..............................................5-19
Door Locks......................................................................3-11
Door unlocking from outside the vehicle...................3-11
Door locking from outside the vehicle.......................3-14
Operating Door Locks from Inside the Vehicle .........3-14
Automatic Door Lock and Unlock Features ..............3-17
Child-Protector Rear Door Locks ..............................3-18
Drive Mode Integrated Control System .........................5-37
Drive mode change alert ............................................5-38
ECO mode climate control .........................................5-38
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Index
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