light FORD F-650/750 2018 Service Manual

WARNING
Sudden accelerations on slippery
surfaces could cause the wheels to
spin, the vehicle to turn sideways on
a crowned road surface or in a turn,
possibly resulting in loss of vehicle control
and personal injury. Activating the Locking Differential
You can lock and unlock the differential
when your vehicle is moving at a constant
speed of less than 25 mph (40 km/h) and
while the wheels are not slipping. Do not
lock the differential when your vehicle is
traveling down steep grades and when
traction is minimal.
The differential lock and differential lock
light automatically disengage at speeds
above 25 mph (40 km/h). The differential
lock remains off until either you restart your
vehicle or you turn the differential lock
switch off then back on.
Servicing a Vehicle with a Locking
Differential
Turn the engine off and raise all drive
wheels of the locker differential axle in
order to prevent your vehicle from moving
when servicing the wheels, tires or brakes.
Axles equipped with a driver-controlled
differential deliver power to both wheels
even when only one wheel is on the ground. WARNING
Failure to raise all drive wheels with
this type of differential could cause
the vehicle to move unexpectedly,
resulting in property damage, personal
injury or death. 2-SPEED REAR AXLE
(If Equipped)
WARNING
Never shift a two-speed axle when
descending a steep grade as this
may cause loss of vehicle control and
result in personal injury. Note:
Do not shift between ranges when
the speed control is on.
A two-speed rear axle allows the driver to
select a low range for greater pulling power
and a high range for greater road speed
and fuel economy. You can also use these
ranges to provide extra steps between
transmission shifts when driving on steep
grades or fuel economy may be factors.
Axle Shifting Note:
Do not shift the axle to LOW when
your vehicle is moving. Use LOW when you
drive a fully loaded vehicle on a severe grade
or in congested traffic. Use HIGH for all
normal driving conditions with a lightly
loaded or partially loaded vehicle.
Note: The axle is set to HIGH by default.
To shift the axle between HIGH and LOW
with the vehicle stopped, place the
transmission in position N, then press and
hold the button for two seconds.
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GENERAL INFORMATION
WARNINGS
Do not drive with your foot resting on
the brake pedal. This results in
abnormally high brake temperatures,
excessive lining wear and increased
stopping distance. Continuous application of the brakes
causes the brakes to overheat,
resulting in temporary loss of braking.
Note:
Occasional brake noise is normal. If
a metal-to-metal, continuous grinding or
continuous squeal sound is present, the
brake linings may be worn-out. Have the
system checked by an authorized dealer. If
your vehicle has continuous vibration or
shudder in the steering wheel while braking,
have it checked by an authorized dealer.
All standard equipment brakes are
self-adjusting. Automatic adjustment,
when required, occurs whenever you apply
and release the brakes during forward or
reverse operation.
Know the required stopping distances for
all driving conditions you may encounter.
For longer brake lining life, take full
advantage of engine braking power when
coming to a stop. See Warning Lamps and
Indicators (page 60).
Wet brakes result in reduced braking
efficiency. Gently press the brake pedal a
few times when driving from a car wash or
standing water to dry the brakes.
If brakes do not grip well:
• Check brake adjustment.
• Check brake linings for excessive wear.
• Check system air pressure on vehicle
equipped with air brakes. •
Let the brakes cool if you have been
using them excessively, as in mountain
driving or after several fast, high-speed
stops.
• If you have been driving through deep
water, gently apply the brakes several
times while your vehicle is moving
slowly.
Brake Over Accelerator
In the event the accelerator pedal
becomes stuck or entrapped, apply steady
and firm pressure to the brake pedal to
slow the vehicle and reduce engine power.
If you experience this condition, apply the
brakes and bring your vehicle to a safe
stop. Move the transmission to park (P),
switch the engine off and apply the parking
brake. Inspect the accelerator pedal for
any interference. If none are found and the
condition persists, have your vehicle towed
to the nearest authorized dealer
Anti-lock Brake System
This system helps you maintain steering
control during emergency stops by keeping
the brakes from locking. This lamp momentarily
illuminates when you turn the
ignition on. If the light does not
illuminate during start up, remains on or
flashes, the system may be disabled. Have
the system checked by an authorized
dealer. If the system is disabled, normal
braking is still effective. If the
brake warning lamp illuminates
when you release the parking brake, have
the system checked by an authorized
dealer.
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If you connect a PLC trailer with
the ignition on, the trailer ABS
light also illuminates. If the light
fails to illuminate, if it remains on after you
start the vehicle or continues to flash, have
the system serviced immediately.
HINTS ON DRIVING WITH
ANTI-LOCK BRAKES
The anti-lock braking system does not
eliminate the risks when:
• You drive too closely to the vehicle in
front of you.
• Your vehicle is hydroplaning.
• You take corners too fast.
• The road surface is poor.
Note: If the system activates, the brake
pedal may pulse and may travel further.
Maintain pressure on the brake pedal. You
may also hear a noise from the system. This
is normal.
PARKING BRAKE
Hydraulic Brakes (If Equipped) WARNINGS
Always set the parking brake and
leave your vehicle with the
transmission in park (P).
This control is for parking only. Do
not leave the vehicle unattended
after setting the parking brake
without placing the transmission in park
(P). We recommend using wheel chocks
for hilly or off-road circumstances. Unexpected and possibly sudden
vehicle movement may occur if you
do not take these precautions. WARNINGS
If the parking brake is fully released,
but the brake warning lamp remains
illuminated, the brakes may not be
working properly. Have your vehicle
checked as soon as possible. Apply the parking brake whenever the
vehicle is parked. To set the parking brake,
pull the handle up until it snaps into the
locked position.
When the parking brake is out of
adjustment, seek service immediately.
The parking brake warning lamp
in the instrument cluster
illuminates, and remains
illuminated (when you switch on the
ignition), until you release the parking
brake. Push the palm release lever (A) on the
parking brake handle (B) and push down
as far as possible to release the brake.
Driving with the parking brake on causes
the brakes to wear out quickly and reduces
fuel economy.
We recommend you not use the parking
brake to stop a moving vehicle. However,
if the normal brakes fail, you can use the
parking brake to stop your vehicle in an
emergency. Since the parking brake only
applies retardation to the rear wheels, the
vehicle's stopping distance increases
greatly and the handling of your vehicle is
adversely affected.
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Releasing Spring Manually
WARNINGS
Do not attempt to disassemble the
parking brake air chamber under any
circumstances as this may cause
serious injury. Block the wheels to help prevent the
vehicle from moving.
Unexpected and possibly sudden
vehicle movement may occur if you
do not take these precautions.
If you release hydraulic pressure from the
spring brake chamber, the power spring
applies the brake. If the hydraulic pressure
can be re-established, you must release
the spring brake in order to move your
vehicle.
Air Brakes (If Equipped)
WARNING
This control is for parking only. Do
not leave the vehicle unattended
after setting the parking brake
without placing the transmission in park
(P). We recommend using wheel chocks
for hilly or off-road circumstances. If the service brakes fail to operate while
your vehicle is moving, you can make an
emergency stop with the parking brake.
Since the parking brake only applies
stopping power to the rear wheels, your
vehicle
’s stopping distance greatly
increases and the handling of your vehicle
is adversely affected. Make repairs
immediately to an inoperative air brake
system circuit. Pull the yellow, dash-mounted parking
brake knob to apply the parking brake.
The parking brake light
illuminates and remains
illuminated (when you switch
the ignition to the on position) until you
release the parking brake.
Releasing the Parking Brake WARNING
When your vehicle is stationary, keep
the brake pedal fully pressed when
shifting gears. Failure to follow this
instruction could result in personal injury,
death or property damage. Note:
Read and understand the following
steps and perform them whenever you
prepare to drive the vehicle.
Note: The parking brake does not disengage
unless sufficient system air pressure is
available.
1. Press and hold the service brake pedal
while the engine is running.
2. Select the appropriate drive gear.
3. Push and hold the yellow dash-mounted parking brake knob until
the parking brake light turns off, then
release.
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Parking Brake Light Illumination Due
to Low Air Pressure
If the air pressure becomes too low at any
time during vehicle operation, the parking
brake may apply and the parking brake
light turns on.
If the parking brake applies due to low air
pressure, immediate service is required to
the parking brake system.
Releasing Spring Brake with Air
Pressure
The air system in all vehicles with
spring-actuated rear wheel parking brakes
has a valve on the governor for connection
to an outside air supply. The valve lets you
recharge the system with air from an
outside source, releasing the
spring-actuated parking brakes. Your
vehicle is now ready to tow in an
emergency.
You can only use an outside air source if
the protected system is in operating
condition. If you cannot restore air pressure
in the protected air system, you must
release the spring-actuated brakes
manually.
Releasing Spring Manually
Do not use impact wrenches as they may
damage the piston and prevent proper
caging of the spring. Do not apply more
than 50 lb.ft (68 Nm) to the release bolt
nut.
1. Remove the stud tool and nut from the
carrying pocket on the brake chamber
assembly. 2. Remove the access plug from the end
of the spring chamber.
3. Insert the release stud through the opening in the chamber and into the
spring pressure plate. 4.
Turn the release stud ¼ turn to engage
the stud tangs with the slot in the
pressure plate. Keep the stud engaged
and install the nut on the release stud.
5. Tighten the nut until the spring is fully caged and brakes released. Do not
loosen or remove the release stud and
nut unless you completely assemble
and securely clamp the brake chamber.
6. After restoring the air pressure, unscrew and remove the release stud
and install in the carrying pocket. Install
the access plug.
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AIR BRAKES (If Equipped)
WARNINGS
Do not drive or continue to drive if the
low air pressure buzzer is sounding
or the brake warning light is lit. These
warnings indicate that air pressure is not
to normal operating level. Continued use
of the vehicle could result in loss of braking
ability. Avoid repeated light application of
the brake pedal. This depletes air
pressure faster and could result in
loss of braking capability. Do not move the vehicle when the
air pressure is insufficient because
the brake system may be inoperative.
After starting the engine, give the air
compressor time to build up the air
pressure to
60 psi (414 kPa) before moving
your vehicle. Periodically check the air pressure gauge
while driving. Pressure should range
between approximately 100 psi (690 kPa)
to
130 psi (896 kPa). The air compressor
governor cut-in and cutout pressure
settings are set at the factory and are not
adjustable. When air pressure is insufficient
(below
60 psi (414 kPa)), a
warning light illuminates and a
buzzer sounds when the ignition is in the
on position. This may happen because
excessive brake applications are depleting
the system air pressure. If this condition
occurs, stop driving your vehicle until the
compressor has fully recharged the air
system.
Select a gear ratio to help slow your vehicle
before descending grades. Supplementing
with brakes, as required, help to safely slow
the vehicle and avoids overspeeding the
engine.
Air Chamber Stroke Indication
Air chamber push rods have orange stroke
indicator markers that warn when the
braking system requires adjustment or
repair. The painted orange indicator is on
the air chamber push rod at the slack
adjuster stroke dimension that requires
service when visible during brake
application.
A qualified service technician should
perform air brake inspection and
adjustment or repairs keeping to the
instructions in the service manual.
Cam Brakes - Automatic Slack
Adjusters WARNING
Do not manually adjust the
automatic slack adjusters to correct
excessive push rod stroke as it may
result in reduced brake effectiveness and
a vehicle crash. Excessive push rod stroke
indicates that a problem exists with the
automatic adjuster, with the installation
of the adjuster, or with foundation brake
components that manual adjustment does
not remedy. Seek service from a qualified
facility for excessive push rod stroke. 125
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To switch the exhaust brake on, press the
button. A light on the instrument cluster
indicates the system is on. Press the button
again to switch it off.
While approaching a steep grade, make
sure that the exhaust brake switch is on.
The exhaust brake begins working as soon
as you remove your foot from the
accelerator pedal.
Before descending a hill or steep grade,
always select the proper gear. If you take
the transmission out of gear while
descending, you may not be able to select
another gear because of maximum
governed RPM.
Make sure the engine speed does not
exceed the maximum allowable engine
RPM. Exceeding the maximum allowable
engine RPM can result in damage to the
engine. Apply the service brakes to reduce
the engine RPM or make a slower descent
by using a lower gear. While driving down a grade, use a low
enough gear to descend safely with a
minimum application of the service brakes.
As a general guideline, use the same gear
as you use to ascend the hill.
Exhaust Brake Operating
Characteristics
The exhaust brake switches on when you
remove your feet from both the accelerator
and clutch pedals and the exhaust brake
is on.
If the brake is working properly, there will
be:
•
A slight change in engine sound when
the exhaust brake turns on.
• A smooth braking effect. Do not expect
a retarding effect similar to sudden,
hard application of the service brakes.
• A retarding force possibly felt acting
against your body during brake
application (depending on the grade
and vehicle load). This force prevents
the vehicle from going much faster.
• Engine temperatures remaining in the
normal operating range.
• A drop in engine RPM (depending on
grade and vehicle load) during a
descent.
• A decrease in road speed when
applying the exhaust brake during a
descent, except when your vehicle is
carrying a heavy load or the grade is
extremely steep. In these instances,
you may need to apply the service
brakes occasionally.
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PRINCIPLE OF OPERATION
The traction control system helps avoid
drive wheel spin and loss of traction.
If your vehicle begins to slide, the system
applies the brakes to individual wheels
and, when needed, reduces engine power
at the same time. If the wheels spin when
accelerating on slippery or loose surfaces,
the system reduces engine power in order
to increase traction.
Note:
The system does not apply the brakes
when vehicle speed is above 25 mph
(40 km/h).
USING TRACTION CONTROL -
VEHICLES WITH: AIR BRAKES WARNING
The stability and traction control
light illuminates steadily if the
system detects a failure. Make sure
you did not manually disable the traction
control system using the information
display controls or the switch. If the
stability control and traction control light
is still illuminating steadily, have the
system serviced by an authorized dealer
immediately. Operating your vehicle with
the traction control disabled could lead to
an increased risk of loss of vehicle control,
vehicle rollover, personal injury and death. Use the traction control switch on the
instrument panel to select Mud/Snow
traction mode.
This is beneficial when your vehicle is stuck
in snow or on a slippery road surface. This
mode allows wheel spin to dig your vehicle
out and allows you to rock your vehicle.
Press the switch again to select standard
traction control. The system automatically
selects standard traction control at the
next ignition cycle. System Indicator Light
Note:
If the traction control light does not
flash during a traction control event or stays
illuminated, the system is not functioning
properly. Take your vehicle to an authorized
dealer for service.
During traction control operation, the
traction control light flashes rapidly and
the engine does not rev-up when you press
further on the accelerator. This is normal
and is no reason for concern.
In Mud/Snow mode, the traction control
light illuminates and flashes slowly. If a
traction event occurs in either mode, the
light flashes rapidly.
USING TRACTION CONTROL -
VEHICLES WITH: HYDRAULIC
BRAKES WARNING
Aggressive driving in any road
conditions can cause you to lose
control of your vehicle increasing the
risk of severe personal injury or property
damage. The occurrence of a traction
control event is an indication that at least
some of the tires have exceeded their
ability to grip the road; this may lead to an
increased risk of loss of vehicle control,
vehicle rollover, personal injury and death.
If you experience a severe road event,
SLOW DOWN. The system automatically turns on each
time you switch the ignition on.
Use the traction control switch on the
instrument panel to switch the system off
or on.
If your vehicle is stuck in mud or snow,
switching traction control off may be
beneficial as this allows the wheels to spin.
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(If Equipped)

Press the switch again to enable the
traction control system.
System Indicator Light
Note:
If the traction control light does not
flash during a traction control event or stays
illuminated, the system is not functioning
properly. Take your vehicle to an authorized
dealer for service.
During traction control operation, the
traction control light flashes rapidly and
the engine does not rev-up when you press
further on the accelerator. This is normal
and is no reason for concern.
When traction control is disabled, the
traction control light illuminates and
flashes slowly.
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PRINCIPLE OF OPERATION
WARNINGS
Vehicle modifications involving
braking system, aftermarket roof
racks, suspension, steering system,
tire construction and wheel and tire size
may change the handling characteristics
of your vehicle and may adversely affect
the performance of the electronic stability
control system. In addition, installing any
stereo loudspeakers may interfere with
and adversely affect the electronic stability
control system. Install any aftermarket
stereo loudspeaker as far as possible from
the front center console, the tunnel, and
the front seats in order to minimize the risk
of interfering with the electronic stability
control sensors. Reducing the
effectiveness of the electronic stability
control system could lead to an increased
risk of loss of vehicle control, vehicle
rollover, personal injury and death. Remember that even advanced
technology cannot defy the laws of
physics. It's always possible to lose
control of a vehicle due to inappropriate
driver input for the conditions. Aggressive
driving on any road condition can cause
you to lose control of your vehicle
increasing the risk of personal injury or
property damage. Activation of the
electronic stability control system is an
indication that at least some of the tires
have exceeded their ability to grip the road;
this could reduce the operator's ability to
control the vehicle potentially resulting in
a loss of vehicle control, vehicle rollover,
personal injury and death. If your electronic
stability control system activates, SLOW
DOWN. The system automatically turns on each
time you switch the ignition on. If a fault occurs in either the stability
control or the traction control system, you
may experience the following conditions:
•
The stability and traction control light
illuminates steadily.
• The stability control and traction
control systems do not enhance your
vehicle's ability to maintain traction of
the wheels.
Vehicles With: Hydraulic Brakes
If a driving condition activates either the
stability control or the traction control
system you may experience the following
conditions:
• The stability and traction control light
flashes rapidly.
• Your vehicle slows down.
• Reduced engine power.
• A vibration in the brake pedal.
• The brake pedal is stiffer than usual.
• If the driving condition is severe and
your foot is not on the brake, the brake
pedal may move as the system applies
higher brake force.
Vehicles With: Air Brakes
If a driving condition activates either the
stability control or the traction control
system you may experience the following
conditions:
• The stability and traction control light
flashes rapidly.
• Your vehicle slows down.
• Reduced engine power.
The stability control system has several
features built into it to help you maintain
control of your vehicle:
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