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144 Driving and Operating
amount of brake force applied.
Please allow for realistic stopping
distances to avoid unnecessary
heavy braking. That means better
braking, longer brake life and safer
driving.
Stopping Distance
The stopping distance of a vehicle
involves reaction time and braking
distance. Deciding to push the
brake pedal is reaction time.
Applying the brake pedal until the
vehicle comes to a complete stop is
braking distance. Average reaction
time is about three-fourths of a
second. But that is only an average.
It might be less with one driver and
as long as two or three seconds or
more with another. Age, physical
condition, alertness, coordination
and eyesight all play a part. Braking
distance will vary based reactiontime, the amount of force applied to
the brake pedal and the speed of
the vehicle.
When driving, bear the stopping
distance in mind. Maintain a speed
and headway distance that allow
you to stop safely even if a hazard
occurs.
Overriding Accelerator with
Brakes
In the unlikely event the accelerator
pedal becomes stuck, apply the
brakes firmly and steadily to reduce
engine power and bring your vehicle
to a safe stop. Turn the engine off,
move the selector lever to the
“P”
(Park) position, and apply the
parking brake. In a safe location,
inspect the accelerator pedal for any
interference and remove the item
causing the interference, if any is
found. If none is found and the
condition persists, have your vehicle
towed to the nearest authorized
dealer.
Braking Techniques
For the most effective braking and
for maximum life from brake system
components, follow these
suggestions when possible:
. Apply the brakes gradually as
road and load conditions permit.
Reduce pedal pressure as
speed drops so that a very light
pressure is used at the end of
the stop.
. Do not pump the brake pedal as
this will only deplete the vacuum
reserve or the hydraulic brake
booster (HBB) accumulator
reserve.
. To get maximum braking while
maintaining vehicle control, use
a "squeeze" braking technique.
Do this by pushing on the brake
pedal with steadily increasing
pressure. If possible, steer
around obstacles when there is
not enough room to stop.
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Brake System Warning Light
Caution
If brake low vacuum warning light
(4500HD, 4500XD models), brake
booster warning light (5500HD,
5500XD models), or brake system
warning light comes on during
operation, have brake system
checked immediately.
Refer to Warning Lights, Gauges,
and Indicators 068.
When the Brakes Do Not Work
{Warning
It is very dangerous to suddenly
pull the parking brake lever all the
way while moving at high speed.
Reduce speed first by shifting
down and then gradually pull the
parking brake lever.
You and others could be seriously
injured. The exhaust brake should be turned
on as soon as service brake
malfunction is detected. This will
slow the engine speed. With the
engine speed under control and
providing the grade conditions
permit, the transmission can be
progressively downshifted using the
exhaust brake in each gear.
Eventually the exhaust brake should
slow the vehicle to a controllable
“crawl.”
Gradually pull the parking
brake lever while firmly holding on
to the steering wheel. Stop the
vehicle on the side of the road. The
vehicle should not be driven further
until corrective measures are taken.
See Exhaust Brake 0222 and
Parking Brake 0220.
Riding the Brake
{Warning
"Riding the brake" by resting your
foot on the pedal, when you do
not intend to brake, can overheat
the brakes and wear out the (Continued)
Warning (Continued)
brake linings faster. This may also
damage the brakes and will waste
fuel. It can also result in reduced
braking performance.
You and others could be seriously
injured.
Applying the Parking Brake
Except in an emergency, do not
apply the parking brake until the
vehicle has come to a complete
stop. Applying the parking brake
before the vehicle has stopped can
cause a breakdown.
Refer toParking Brake 0220.
Parking Safely on a Slope
Avoid parking your vehicle on a
slope as much as possible and
choose a level and flat place. If you
must park your vehicle on a slope,
be sure to set the parking brake
fully. Make sure that the vehicle
does not move, and block the
wheels with chocks for added
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safety. Also, leave the vehicle in
gear to further ensure that it will not
move. Leave the steering wheel
turned such that the vehicle will be
stopped by an obstruction (for
example, the curb) in the unlikely
event that it moves.
Stopping and Parking with the
Engine Running
{Warning
When parking with the engine
running, first come to a complete
stop, then firmly apply the parking
brake, then move the selector
lever to the "P" (Park) position.
Unless you take these steps, any
unintended pressure on the
accelerator pedal could cause a
crash.
To reduce the chance of personal
injury and/or vehicle damage due
to engine overheating, never
leave the engine idling without an
alert driver present. If the engine(Continued)
Warning (Continued)
should overheat, as indicated by
the engine coolant temperature
gauge, immediate action is
required to correct the condition.
Continued operation of the
engine, even for a short time, may
result in a fire. Do not engage the
exhaust brake while the engine is
idling as this may cause engine
overheating.
The diesel particulate filter (DPF)
may automatically start
regeneration when the vehicle is
stopped and parked with the
engine running. To prevent a fire,
make sure there is no flammable
material near the muffler, DPF,
and exhaust pipe. Be careful not
to get burned by hot exhaust
gases.
You and others could be seriously
injured. Do Not Forget to Release the
Parking Brake
Pulling away with the parking brake
still applied can damage the brake
system.
Before pulling away, make sure the
parking brake is not set by checking
that the parking brake indicator light
is not on.
Be Sure to Have the Engine
Running When the Vehicle is
Moving
{Warning
When the engine is not running,
the power steering system does
not work so the steering wheel is
hard to turn. Also, the brake
booster does not work so there is
little braking ability. If you coast
down a slope without the engine
running, you would not be able to
properly control the vehicle and
could have a crash.
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Parking, or Leaving
Driver’s Seat
{Danger
It can be dangerous to get out of
your vehicle if the selector lever is
not fully in "P" (Park) or the
parking brake is not applied all
the way. Your vehicle can roll or
move suddenly.
To be sure your vehicle will not
move, even when you are parking
on level ground, follow the steps
below. (If you have to park on a
hill, also turn your front wheels so
the vehicle will roll away from
traffic.)
You and others could be seriously
injured or killed.
1. Hold the regular brake pedal down with your right foot and
apply the parking brake all the
way before shifting the
transmission. Follow the
Parking Brake instructions in
this manual for your vehicle. 2. To move the selector lever to
"P" (Park), hold in the button
on the lever and push the lever
all the way toward the front of
your vehicle.
3. Turn the key to "LOCK".
4. Remove the key and take it with you.
5. Before you leave the driver's seat, be sure the vehicle is not
moving, or check that your
vehicle is in Park by trying to
pull the selector lever out of "P"
(Park) by pulling the selector
lever toward you without
pushing the button. If you can
do this, it means that the
selector lever was not fully
locked into "P" (Park).
Do Not Touch the Selector Lever
While the Vehicle is Stationary
with the Engine Idling
Do not touch the selector lever while
the vehicle is stationary with the
engine idling. If you touch the
selector lever at this time, a gear
could be selected and the vehicle
could move even with the parking brake applied. The risk of knocking
against the selector lever and
causing a crash is particularly great
when you move in or out of
your seat.Driving Down a Long Slope
When driving down a long slope,
use the exhaust brake together with
the foot brake. Using the exhaust
brake and low-gears reduces the
work load on the foot brakes and
yields greater braking force. Even
so, use the foot brakes
appropriately to prevent the engine
over-revving.
Frequent use of the foot brakes can
cause vapor lock and brake fade,
resulting in reduced brake
effectiveness.
Brake Fade :
Frequent use of the
brakes can cause the brakes to
overheat so that the frictional force
of the brake linings decreases and
the brakes become less effective
than normal. This phenomenon is
called brake fade.
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Vapor Lock :If the brakes overheat
due to frequent use, the heat can
cause the brake fluid to boil so that
air bubbles are created in the brake
fluid. Pressing the brake pedal
simply compresses the air bubbles;
pressure is not transmitted to the
wheel cylinders, so the brakes'
effectiveness sharply deteriorates.
This phenomenon is called
vapor lock.
Even so, you should be very careful
when using engine braking in a low
gear because the engine is likely to
over-rev.
See Exhaust Brake 0222 and
Selector Lever 0214.
Do not adjust the exhaust brake
valve.
The engine should never be allowed
to exceed the governed speed.
Supplement the exhaust brake with
vehicle service brakes intermittently
and/or shift to higher transmission
gear to prevent engine overspeed.
A rule of thumb for gear selection is
that the vehicle should be driven
down a grade in the same gear that
would be used to climb that grade.{Warning
To reduce the risk of personal
injury, before going down a steep
or long grade, reduce speed, turn
on the exhaust brake and shift the
transmission to the next lower
gear. This will help control your
speed. Do not hold the brake
pedal down too long or too often
while going down a steep or long
grade. This could cause the
brakes to get hot and not to work
as well. As a result, the truck will
not slow down at the usual rate.
Failure to take these steps could
result in loss of vehicle control.
You and others could be seriously
injured.
Brake Effectiveness When the
Vehicle Has Been Driven on a
Flooded Road or Washed
{Warning
When the vehicle is driven on a
flooded road, parked on a flooded
road or washed, water can get
into the brakes and reduce their
effectiveness. If the brakes do not
work well afterward, drive slowly
and gently press the brake pedal
several times until the brakes dry
out and start working normally.
Always do this after driving
through water or washing the
vehicle to help reduce the risk of
personal injury. Before parking
the vehicle in winter, press the
brake pedal several times in the
same way to get rid of moisture in
the brakes. Otherwise, the
moisture in the brakes may freeze
and make the vehicle immovable.
You and others could be seriously
injured.
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If the vehicle must be driven on a
flooded road or is parked in an area
that becomes flooded, promptly
perform a check for the following
points:
.Effectiveness of the brakes
. Water-ingress or damage to
drum brakes, disc brakes
. Engine damage due to
water-ingress
. Shorting of electrical
components
. Oil level and degradation
(cloudiness) of the engine,
transmission, differential
. Greasing of each components
(lubrication)Steering
Do Not Leave the Steering
Wheel Fully Turned for a
Long Time
{Warning
If you leave the steering wheel
fully turned for a long time, the oil
in the power steering oil pump will
become extremely hot. This
would cause poor lubrication, oil
tank damage and seal
deterioration, leading to power
steering oil pump damage, power
steering unit damage and power
steering hose damage. As a
result the steering wheel could
become extremely hard to turn
and a fire or a crash could occur.
You and others could be seriously
injured.
Steering Wheel
If the steering parts have excess
play or looseness or if any abnormal
condition is noted, have the steering
system checked immediately.
Driving on Wet Roads
Driving on Slippery Surface or
Driving in Bad Weather (Rain,
Icy Roads, Snowy Roads, etc.)
In bad weather, visibility is reduced
and slippery road surfaces increase
stopping distances. Drive more
slowly than you would in good
weather. Also, avoid sharp turns of
the steering wheel and hard
braking. Use engine brakes together
with the foot brakes to decelerate.
Using the exhaust brake on a
slippery road surface could cause
the tires to slip.
You may not realize the surface is
slippery until the vehicle is skidding.
Learn to recognize warning clues—
such as enough water or ice on the
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road to make a "mirrored surface"—
and slow down when there is any
doubt.
There is a risk of hydroplaning,
particularly where water tends to
collect on the road surface. Drive at
speeds that allow you to stay in
complete control.
If you cannot avoid driving on a
flooded road, first check the depth
of the water and then drive through
the water at a slow, constant speed.
There is a risk that water will get
into the engine's cylinders and
cause engine damage (water
hammering). Keep your speed
down, and drive with great care.
Hydroplaning :If a vehicle is driven
at high speed on a road that is
covered with water, a layer of water
can form between the tires and road
surface, causing the tires to lose
their grip and slide across the water.
This phenomenon is called
hydroplaning. It is dangerous
because it makes the steering
wheel and brakes useless.
Refer to Wheels and Tires 0295.Hill and Mountain Roads
Narrow or Congested Roads
When passing or overtaking a
vehicle on a narrow mountain road
or on a narrow or congested urban
road, pay careful attention to
obstacles on either side and to the
condition of the shoulder of
the road.
When turning, the rear wheels will
follow tighter curves than the front
wheels. Use the mirrors to confirm
safety.
Driving Uphill or Downhill
Downshifts are performed for two
main purposes:
.
For engine braking on a steep
and/or long downward slope
. For responsiveness and
economy on an uphill slope
Drive at a speed that does not
cause the tachometer needle to
enter the red zone.
Uphill
Shift down well ahead of time in
order to avoid a heavy load to the
engine.
Downhill
.
Be careful not to drive too fast
on a downhill road.
. Use the same gear(s) that you
used to drive up the hill. Also,
use the exhaust brake in order
to avoid going too fast.
. Do not let the engine overrun.
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.When going down on a steep
slope, avoid driving the vehicle
backward as much as possible.
Drive it forward slowly on the
down slope.
. Compared with forward
movement, the braking distance
of backward movement is longer,
and the steering response of
that is worse.
. If you must drive the vehicle
backward, drive it very carefully
and gradually by moving and
stopping repeatedly in order to
stop it any time.
Engine Brake : Engine brake is the
braking effect that occurs when you
release the accelerator pedal while
driving. The lower the gear, the
stronger the engine brake.
Exhaust Brake : The exhaust brake
is a system that closes the exhaust
pipe and uses the force of the
exhaust emissions to enhance the
effectiveness of engine brake. Overrunning :
An engine overrun is
an engine-speed increase that
causes the tachometer needle to
enter the red zone. It is dangerous
because it can cause engine failure.
Winter Driving
Recommendations for Driving
in Cold Regions
The following recommendations
apply to snowbound regions and to
mountainous regions, ski resorts
and other areas of extreme cold
and/or snowfall. Please follow them
also for reference in winter in other
regions.
For the sake of your vehicle, make
the winter preparations described in
the links below. Also have these
preparations made before driving to
a cold region.
See Engine Oil 0245.
See Engine Coolant 0253.
See Washer Fluid 0262.
See Battery - North America 0269.
When Ice Prevents You from
Putting Your Key in the Door
or Opening the Door
If you try to force the key into the
door, you could bend it. And if you
try to pull the door open with undue
force, the rubber seal around the
door could come unstuck or become
damaged. Use warm water to melt
the ice, then quickly wipe it away
and open the door.
If the wipers, electric door mirrors,
or power windows freeze up, also
use warm water to melt the ice and
then operate the system. Otherwise,
you could damage the mechanism
and drain the battery. After that,
wipe the water away.
Before Driving in Cold Regions
Getting In and Out of the Vehicle
The step can get icy in cold regions.
Be careful not to slip when getting in
and out of the vehicle.