Ford Super Duty (2017 year). Manual — part 82

Severe Climates

If you drive in extremely cold climates:
•

It may be necessary to increase the
coolant concentration above 50%.

•

A coolant concentration of 60%
provides improved freeze point
protection. Coolant concentrations
above 60% decrease the overheat
protection characteristics of the
coolant and may cause engine
damage.

If you drive in extremely hot climates:
•

It may be necessary to decrease the
coolant concentration to 40%.

•

A coolant concentration of 40%
provides improved overheat protection.
Coolant concentrations below 40%
decrease the freeze and corrosion
protection characteristics of the
coolant and may cause engine
damage.

Vehicles driven year-round in non-extreme
climates should use prediluted coolant for
optimum cooling system and engine
protection.

Fail-Safe Cooling

Fail-safe cooling allows you to temporarily
drive your vehicle before any incremental
component damage occurs. The fail-safe
distance depends on ambient
temperature, vehicle load and terrain.

How Fail-Safe Cooling Works

If the engine begins to overheat, the
coolant temperature gauge moves toward
the red zone:

A warning lamp illuminates and
a message may appear in the
information display.

If the engine reaches a preset
over-temperature condition, the engine
automatically switches to alternating
cylinder operation. Each disabled cylinder
acts as an air pump and cools the engine.

When this occurs, your vehicle still
operates, however:
•

Engine power is limited.

•

The air conditioning system turns off.

Continued operation increases the engine
temperature, causing the engine to
completely shut down. Your steering and
braking effort increases in this situation.

When the engine temperature cools, you
can re-start the engine. Have your vehicle
checked as soon as possible to minimize
engine damage.

When Fail-Safe Mode Is Activated

WARNINGS

Fail-safe mode is for use during
emergencies only. Operate your
vehicle in fail-safe mode only as long

as necessary to bring your vehicle to rest
in a safe location and seek immediate
repairs. When in fail-safe mode, your
vehicle will have limited power, will not be
able to maintain high-speed operation, and
may completely shut down without
warning, potentially losing engine power,
power steering assist, and power brake
assist, which may increase the possibility
of a crash resulting in serious injury.

Never remove the coolant reservoir
cap while the engine is running or hot.

Your vehicle has limited engine power
when in the fail-safe mode, drive your
vehicle with caution. Your vehicle does not
maintain high-speed operation and the
engine may operate poorly.

Remember that the engine is capable of
automatically shutting down to prevent
engine damage. In this situation:

331

1.

Pull off the road as soon as safely
possible and switch the engine off.

2. If you are a member of a roadside

assistance program, we recommend
that you contact your roadside
assistance service provider.

3. If this is not possible, wait a short

period for the engine to cool.

4. Check the coolant level. If the coolant

level is at or below the minimum mark,
add prediluted coolant immediately.

5. When the engine temperature cools,

you can re-start the engine. Have your
vehicle checked as soon as possible to
minimize engine damage.

Note: Driving your vehicle without repair
increases the chance of engine damage.

Engine Coolant Temperature
Management

(If Equipped)

WARNING

To reduce the risk of crash and injury,
be prepared that the vehicle speed
may reduce and the vehicle may not

be able to accelerate with full power until
the coolant temperature reduces.

If you tow a trailer with your vehicle, the
engine may temporarily reach higher a
temperature during severe operating
conditions, for example ascending a long
or steep grade in high ambient
temperatures.

At this time, you may notice the coolant
temperature gauge moves toward the red
zone and a message may appear in the
information display.

You may notice a reduction in vehicle
speed caused by reduced engine power.
In order to manage the engine coolant
temperature. Your vehicle may enter this
mode if certain high-temperature and
high-load conditions take place. The
amount of speed reduction depends on
vehicle loading, grade and ambient
temperature. If this occurs, there is no need
to pull off the road. You can continue to
drive your vehicle.

The air conditioning may automatically
turn on and off during severe operating
conditions to protect the engine from
overheating. When the coolant
temperature decreases to the normal
operating temperature, the air conditioning
turns on.

If the coolant temperature gauge moves
fully into the red zone, or if the coolant
temperature warning or service engine
soon messages appear in your information
display, do the following:

1.

Pull off the road as soon as safely
possible and shift the transmission into
park (P).

2. Leave the engine running until the

coolant temperature gauge needle
returns to the normal position. After
several minutes, if the temperature
does not drop, follow the remaining
steps.

3. Switch the engine off and wait for it to

cool. Check the coolant level.

4. If the coolant level is at or below the

minimum mark, add prediluted coolant
immediately.

5. If the coolant level is normal, restart

the engine and continue.

332

ENGINE COOLANT CHECK -
6.7L DIESEL

WARNINGS

Do not add engine coolant when the
engine is hot. Steam and scalding
liquids released from a hot cooling

system can burn you badly. Also, spilling
coolant on hot engine parts can burn you.

Do not put engine coolant in the
windshield washer fluid container. If
sprayed on the windshield, engine

coolant could make it difficult to see
through the windshield.

To reduce the risk of personal injury,
make sure the engine is cool before
unscrewing the coolant pressure

relief cap. The cooling system is under
pressure. Steam and hot liquid can come
out forcefully when you loosen the cap
slightly.

Do not add coolant further than the
MAX mark.

When the engine is cold, check the
concentration and level of the coolant at
the intervals listed in the scheduled
maintenance information. See Scheduled
Maintenance (page 567).

Note: Make sure that the coolant level is
between the MIN and MAX marks on the
coolant reservoir.

Note: Coolant expands when it is hot. The
level may extend beyond the MAX mark.

Maintain coolant concentration within
48% to 50%, which equates to a freeze
point between -30°F (-34°C) and -34°F
(-37°C). Coolant concentration should be
checked using a refractometer. We do not
recommend the use of hydrometers or
coolant test strips for measuring coolant
concentration.

Adding Coolant

WARNING

Never remove the coolant reservoir
cap while the engine is running or hot.

Note: Automotive fluids are not
interchangeable. Do not use coolant or
windshield washer fluid outside of its
specified function and vehicle location.

Note: Do not use stop leak pellets, cooling
system sealants, or non-specified additives
as they can cause damage to the engine
cooling or heating systems. Resulting
component damage may not be covered by
the vehicle Warranty.

It is very important to use prediluted
coolant approved to the correct
specification in order to avoid plugging the
small passageways in the engine cooling
system. See Capacities and
Specifications (page 428). Do not mix
different colors or types of coolant in your
vehicle. Mixing of engine coolants or using
an incorrect coolant may harm the engine
or cooling system components and may
not be covered by the vehicle Warranty.

Note: Coolants marketed for all makes and
models may not be approved to Ford
specifications and may cause damage to
the cooling system. Resulting component
damage may not be covered by the vehicle
Warranty.

If the coolant level is at or below the
minimum mark, add prediluted coolant
immediately.

333

For vehicles with overflow coolant systems
with a non-pressurized cap on the coolant
recovery system, add coolant to the
coolant recovery reservoir when the engine
is cool. Add prediluted coolant to the
maximum level. For all vehicles which have
a coolant degas system with a pressurized
cap, or if it is necessary to remove the
coolant pressure relief cap on the radiator,
follow these steps to add engine coolant:

1.

Turn the engine off and let it cool.

2. Unscrew the cap slowly. Any pressure

escapes as you unscrew the cap.

3. Fill the coolant reservoir slowly with

prediluted engine coolant to within the
minimum and maximum range on the
engine coolant reservoir. If you
removed the radiator cap in an
overflow system, fill the radiator until
the coolant is visible and the radiator
is almost full. If coolant is added to
bring the level within the minimum and
maximum range when the engine is not
cold, the system may remain
underfilled.

4. Replace the coolant reservoir cap, turn

it clockwise until you feel a strong
resistance.

5. Check the coolant level in the coolant

reservoir the next few times you drive
your vehicle. If necessary, add enough
prediluted engine coolant to bring the
coolant level to the proper level.

Note: If prediluted coolant is not available,
use the approved antifreeze concentrate
diluting it to 50/50 with distilled water. See
Capacities and Specifications (page 428).
Using water that has not been deionised
may contribute to deposit formation,
corrosion or plugging of the small cooling
system passageways.

If you have to add more than 1.1 qt (1 L) of
engine coolant per month, have your
vehicle checked as soon as possible.
Operating an engine with a low level of
coolant can result in engine overheating
and possible engine damage.

Note: During normal vehicle operation, the
coolant may change color from orange to
pink or light red. As long as the coolant is
clear and uncontaminated, this color change
does not indicate the coolant has degraded
nor does it require the coolant to be drained,
the system to be flushed, or the coolant to
be replaced.

Note: In case of emergency, you can add a
large amount of water without coolant in
order to reach a vehicle service location.
Water alone, without coolant, can cause
engine damage from corrosion, overheating
or freezing. When you reach a service
location, you must have the cooling system
drained, flushed and refilled using the
correct specification prediluted coolant or
antifreeze concentrate. See Capacities and
Specifications (page 428).

Do not use the following as a coolant
substitute:
•

Alcohol.

•

Methanol.

•

Brine.

•

Any coolant mixed with alcohol or
methanol antifreeze.

Alcohol and other liquids can cause engine
damage from overheating or freezing.

Do not add extra inhibitors or non-specified
additives to the coolant. These can be
harmful and compromise the corrosion
protection of the coolant.

334