CHEVROLET LOW CAB FORWARD 2020 Owner's Manual

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
130 Driving and Operating
The careful attention you give your
vehicle, as far as maintenance is
concerned, will also help fuel
economy.
Protection of Engine against
Overcooling
Overcooling of the engine not only
accelerates wear of the vital engine
parts but also hurts fuel economy.
Distracted Driving
Do Not Use a Mobile Phone
While Driving
{Warning
Drivers should never use mobile
telephones or car phones in any
mode other than Hands Free
while driving. Doing so is
dangerous. Using a mobile
telephone while driving could
result in a crash because you
would not be paying full attention
to your surroundings. If you are(Continued)
Warning (Continued)
driving and you wish to use a
mobile telephone, first stop the
vehicle in a safe place.
You and others could be seriously
injured.
Control of a Vehicle
Warnings for Driving
{Warning
Concentrate on driving safely,
obeying all legally designated
speed limits, road signs and
traffic signals.
If you notice any abnormal noise,
abnormal smell or abnormal
vibration from any part of the
vehicle, immediately stop the
vehicle in a safe place and
perform checks.
(Continued)
Warning (Continued)
If a warning light comes on or a
buzzer sounds while you are
driving, immediately stop the
vehicle in a safe place and
perform checks.
Slow down sufficiently when
approaching a curve. Applying the
brakes or sharply turning the
steering wheel while turning the
curve could cause the cargo to
shift, the tires to slip and the
vehicle to tip onto its side.
Avoid scraping the tire sidewalls
against curbstones or driving over
dips and protrusions in the road
surface. You could damage the
tires, resulting in a blowout or
flat tire.
You and others could be seriously
injured.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 131
Pulling Away After Stopping
and Parking
Before pulling away, check that
there are no children or obstructions
around the vehicle and confirm that
it is safe to pull away.
If you cannot see the area behind
your vehicle well enough to confirm
it is safe to back up, get out of the
vehicle and check behind it.
Make it a habit to look around and
confirm that it is safe to pull away
after a temporary stop (at traffic
lights, for example).
If the Windshield Fogs Up
Use the heater to blow hot air on the
windshield or dehumidify the cabin
using the air conditioner and place
the outlet selector knob in the
5or
4position.
Place the air selector lever in the
outside air position.
Nighttime Visibility
If there is an old film on the
windshield, the lights of oncoming
traffic will be reflected in many directions, making it hard for you to
see ahead. Use glass cleaner to
clean the glass and the wiper
blades.
Worn wiper blades cannot wipe the
windshield clean and thus cannot
maintain visibility. When the wiper
blades become worn, replace them
with new ones.
Do Not Attach Accessories to
the Windshield or Windows
{Warning
Do not attach ornaments, films or
other accessories to the
windshield or windows. They
would impair visibility. Also, any
plastic suction cups used to
attach accessories could cause a
fire or a crash by acting as
lenses.
You and others could be seriously
injured.
Never Stop the Engine While
Driving
{Warning
Do not move the engine control
switch away from the "ON"
position while the vehicle is being
driven.
If the engine stops while the
vehicle is moving, the brake
booster does not work, and the
brakes would not work properly.
The engine could also be
damaged.
Stopping the engine while driving
would be extremely dangerous
because the power steering
would stop working, making the
steering wheel extremely hard
to turn.
Stopping the engine while driving
would be extremely dangerous
because the warning lights,
(Continued)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
132 Driving and Operating
Warning (Continued)
indicator lights and other
electrical circuitry would
completely stop working.
Placing the engine control switch
in the "LOCK" position while
driving would be extremely
dangerous because the key could
come out, causing the steering
wheel to lock so that you could
not turn it.
You and others could be seriously
injured.
Avoid Unnecessary Idling of
the Engine
If the engine idles too long, the
engine coolant temperature will fall
below the operating range. Low
engine operating temperature
causes several conditions that are
harmful to engine operation and life.
Incomplete combustion of fuel in an
engine that is not fully warmed-up
causes crankcase dilution and
forms lacquer and gummy depositson valves, pistons, and rings. It also
causes rapid accumulation of
sludge within the engine.
Driving at Night
Nighttime driving is more dangerous
than daytime driving because the
field of view is narrower. Keep your
speed down, and maintain an ample
headway distance.
Metallic Plinking Sound from
the Muffler
Immediately after stopping the
engine, you may hear a metallic
plinking sound from the muffler. This
sound occurs as the muffler cools
down and contracts. It does not
indicate an abnormality or
breakdown.
When the Silencer and
Exhaust Pipe are Hot
{Warning
When the engine is running and
immediately after vehicle
operation, the DPF, silencer, and
exhaust pipe are extremely hot.
Be careful not to inadvertently
touch them when working near
them (for example, tilting the cab
or operating an attachment). You
and others could be seriously
injured.
Recommendations for Driving
in Hot Regions
The engine is more likely to
overheat in an environment where
the ambient temperature is high. To
prevent the engine from
overheating, pay attention to the
following points:
.
If the engine does not contain
the appropriate concentration of
engine coolant, overheating is
likely to occur.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 133
Refer toEngine Coolant 0243.
. Do not put well water, river water
or other hard water in the engine
cooling system. It would hasten
the formation of rust and scale.
. If foreign matter (insects, mud,
etc.) gets stuck in the radiator's
air passages, the cooling
system's performance will
deteriorate. Check the air
passages for clogging, and
remove any foreign matter using
water under low pressure.
Refer to Exterior Care 0307.
When Turning, the Rear
Wheels will Follow Tighter
Curves than the Front Wheels
Use the mirrors to confirm safety.
Sidewinds
If the vehicle catches a sidewind
and drifts sideways, firmly grip the
steering wheel, decelerate to a
speed that allows you to stay
completely in control, and make a directional correction. The vehicle
may catch strong sidewinds in the
following situations:
.
Emerging from a tunnel
. Driving over a bridge
. Driving on an embankment
. Driving through a cutting
. Being overtaken by a large truck
or bus
. Overtaking a large truck or bus
Flat Tire
If a blowout or flat tire occurs while
you are driving, calmly grip the
steering wheel and gradually apply
the brakes to decelerate. (Hard
braking would be dangerous
because it could cause the steering
wheel to be pulled to one side.)
Stop the vehicle in a safe place, and
change the tire.
Hard Bump Under Vehicle
If the underside of the vehicle
receives a hard bump, stop in a safe
place where the vehicle will not
obstruct traffic and check for brake fluid leakage, fuel leakage and
component damage. If any part of
the vehicle is damaged or broken,
promptly have the vehicle inspected
and repaired.
Highways
.
Speeds on highways are higher
than those on regular roads, so
there is more danger. Also, a
breakdown on a highway
represents a hazard to other
vehicles and can cause a crash.
Concentrate on safe driving.
Remember to perform daily
pre-operation inspections and
use highway driving techniques.
When performing daily
pre-operation inspections,
perform the checks shown in the
table on the left with particularly
great care.
Refer to Owner Checks and
Services 0330.
. When merging with traffic on a
highway, use the turn signal
lights to indicate your intentions
ahead of time. Speed up
sufficiently when you are in the

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
134 Driving and Operating
acceleration lane. Pay attention
to vehicles behind you and to
conditions in the lane you are
joining. Merge in such a way that
you do not obstruct vehicles in
the lane.
. Your sense of how fast you are
traveling becomes distorted on
long highway drives. Constantly
keep an eye on the
speedometer, and maintain a
suitable headway distance.
. During high-speed driving, even
a little turn of the steering wheel
causes a big movement of the
vehicle. Turn the steering wheel
slowly.
. Excessive use of the brake
pedal is extremely dangerous
because it rapidly wears the
brake linings and causes brake
fade. Make effective use of the
engine brake and the exhaust
brake when you want to
decelerate.
. When you want to turn off a
highway, use the turn signal
lights to indicate your intentions ahead of time. Paying attention
to vehicles behind you, turn off
the highway smoothly so as not
to obstruct other vehicles.
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.
Braking
Brake Operation
The brakes give strong braking
force with only light pressure on the
pedal. Do not press the brake pedal
hard except in the event of an
emergency.
Actual stopping distances vary
greatly. Your ability to stop safely
will be greatly affected by the
surface of the road, whether it is
pavement or gravel; the condition of
the road, whether it is wet, dry or
icy; tire tread; the condition of the
brakes; the weight of the vehicle;
the weight of the load; and the 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 DistanceThe 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 reaction

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 135
time, 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. Brake System Warning LightCaution
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 056.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
136 Driving and Operating
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 0213 and
Parking Brake 0211.
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 0211.
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 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)

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 137
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.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
138 Driving and Operating
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. 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 0213
and
Selector Lever 0205.
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.

Chevrolet Low Cab Forward 5.2L Diesel Engine 4500 HD/XD/5500 HD/XD
Owner Manual (GMNA-Localizing-U.S.-13337621) - 2020 - crc - 12/5/18
Driving and Operating 139
{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.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)