2020 CHEVROLET LOW CAB FORWARD brakes

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
Storage 47
Model MaximumGVWR
kg (lb.) Front GAWR
Capacitykg (lb.) Rear GAWR
Capacitykg (lb.)
4500HD 6 577 (14,500) 2 431 (5,360) 4 482 (9,880)
4500XD 7 258 (16,000) 3 007 (6,630) 4 998 (11,020)
5500HD 8 142 (17,950) 3 098 (6,830) 5 888 (12,980)
5500XD 8 845 (19,500) 3 300 (7,275) 6 196 (13,660)
Maximum Front and Rear Axle
Weights
The weight of the cargo load must
be properly distributed over both the
front and rear axles. The “VIN,Weight Rating, and Greenhouse
Gas (GHG) Emissions Plate”
shows
the maximum weight that the front
axle can carry (front GAWR). It also
shows the maximum weight that the
rear axle can carry (rear GAWR).
The GVWR is the maximum
permissible loaded weight of the
vehicle and takes into account the
capabilities of the engine,
transmission, frame, springs,
brakes, axles and tires. Actual loads
at the front and the rear axles can
only be determined by weighing the
vehicle. This can be done at
highway weigh stations or other
such places. See your dealer for help. The cargo load should be
distributed on both sides of the
center line as equally as possible.
Tires
The tires on your truck must be of
the proper size and properly inflated
for the load that you are carrying.
The
“VIN, Weight Rating, and
Greenhouse Gas (GHG) Emissions
Plate” shows the originally equipped
tire size and recommended inflation
pressures.
For the vehicle plate location, see
Vehicle Identification Number (VIN)
0 343.
See “Tire Load and Inflation Table”
under Tire Pressure 0297.

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
Instruments and Controls 63
warning light does not go away,
brake inspection and maintenance
should be performed.
Check and Corrective Action
1. Check to see that the parkingbrake has been fully released.
If it has, check the following:
2. Turn on the exhaust brake to help slow the vehicle.
3. Pull off the road and stop carefully. Remember that
stopping distances may be
longer, the pedal may be
harder to push, and the pedal
may go down farther than
normal.
4. Check the brake fluid reservoir on the left side of the
instrument panel. If low, add
fluid as needed.
5. If the brake fluid is not low: Try out the brakes by starting and
stopping on the shoulder of the
road, then either drive
cautiously at a safe speed to
the nearest dealer for repair,
if you judge driving to be safe; or have the vehicle towed to
the nearest dealer for repair.
Continued driving without the
necessary repairs could be
dangerous.
If this warning light stays on, see
your dealer.
The regular braking system is a split
system designed so that one part
will provide some braking if there is
a loss of hydraulic pressure in the
other part of the system.
{Warning
If this warning light comes on
while the engine is running,
immediately stop the vehicle at a
safe place well clear of traffic and
contact your dealer for inspection.
When the brake system warning
light is illuminated, brake
effectiveness may be decreased.
When this happens, strongly
press the brake pedal.
See Brakes 0253.
Parking Brake Light
This indicator light comes on when
the parking brake lever is pulled
with the engine control switch on.
This light also stays on when the
parking brake is not fully released
and the engine control switch is on.
If this warning light stays on, see
your dealer.
The illumination of the parking brake
light does not necessarily ensure
firm application of the parking brake.
The parking brake lever must be
sufficiently pulled up and locked.
Be careful not to drive the vehicle
with the parking brake lever still
pulled up.

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
64 Instruments and Controls
Brake Low Vacuum Warning
Light
This light should come on briefly
when the engine control switch is
turned to the ON position, and then
should go out after the engine is
started. If the light does not come
on when the engine control switch is
turned to ON, it could indicate a
burned out bulb or a blown fuse.
Have the system repaired if the light
does not come on during this check.
The warning light and buzzer will
come on simultaneously when the
brake booster’s vacuum or pressure
becomes insufficient either during
driving or when the engine control
switch is in the ON position, or when
there is an abnormality in the
charging system, such as an
alternator malfunction or loosening
or splitting of the fan belt or whenever the hydraulic brake
booster (HBB) becomes faulty. The
warning buzzer will stop sounding
when the parking brake is engaged.
On 4500HD and 4500XD, the brake
low vacuum warning light and
warning buzzer should come on to
indicate low vacuum reserve for
brake power assist. At the same
time, the Back up Electric Vacuum
Pump operates.
(5500HD, 5500XD models) When
the HBB pressure is low, and/or the
HBB fluid (Dexron
–VI) level is low,
the light and warning buzzer should
come on. Do not use brake fluid in
the brake booster reservoir. Use
only Dexron –VI ATF.
If this happens while driving:
. Do not pump the brakes. The
system is designed to stop the
truck with reserve power assist if
the pedal is held down. This
reserve is greatly reduced each
time you apply and release the
brakes.
. Stopping distance may be
longer. .
You may have to push much
harder on the brake pedal.
. Have the vehicle repaired before
you continue driving.
The buzzer stops when the selector
lever is shifted to the P position.
{Warning
Do not drive while the buzzer
sounds as the brakes are not
operating to their full capacity.
You and others could be seriously
injured.
Antilock Brake System
(ABS) Warning Light
This light comes on briefly when the
engine control switch is turned to
the ON position, and then should go

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
Instruments and Controls 65
out after approximately
three seconds. If the light does not
come on, have it fixed so it will be
ready to warn if there is a problem.
If this warning light stays on more
than three seconds or comes on
while driving, there is a problem in
the Anti-lock Brake System (ABS).
In this case, the ABS stops working
but the brakes still function as
ordinary service brakes.
{Warning
If this warning light comes on
while driving, immediately stop
your vehicle at a safe place well
clear of traffic and take the
following actions.1. Stop the engine.
2. Restart the engine. Check ifthe ABS warning light
comes on and then goes
out. If it does, there is no
problem. The ABS operates
normally.
(Continued)
Warning (Continued)
3. Move the vehicle slowlyforward. Gradually increase
the speed to 15 km/h
(9 mph). If the light goes off,
the ABS is normal.
If the light does not come on or
go out, or comes on frequently,
contact your dealer immediately
and have the system repaired.
Even if a problem has occurred in
the ABS, the brakes will still work
as normal brakes. In this case,
the ABS has no influence on the
operation of the brake system.
See Brake System Warning Light
(Parking Brake Light) 062 and
Antilock Brake System (ABS) 0207.
Exhaust Brake Light
This light comes on when the
exhaust switch is pulled and the
engine is running. See Exhaust
Brake 0213.
Service Transmission
Warning Light
This light comes on briefly when the
engine control switch is in the ON
position, as a check to show the
light is working. It should go out
when the engine is started.

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
128 Driving and Operating
Driving and
Operating
Driving Information
Driver Behavior . . . . . . . . . . . . . . . 129
Driving for Better FuelEconomy . . . . . . . . . . . . . . . . . . . . 129
Distracted Driving . . . . . . . . . . . . 130
Control of a Vehicle . . . . . . . . . . . 130
Braking . . . . . . . . . . . . . . . . . . . . . . . 134
Steering . . . . . . . . . . . . . . . . . . . . . . 140
Driving on Wet Roads . . . . . . . . 140
Hill and Mountain Roads . . . . . 141
Winter Driving . . . . . . . . . . . . . . . . 142
If the Vehicle Is Stuck . . . . . . . . 144
Emergencies (Troubleshooting) . . . . . . . . . . . 145
Emergencies (Disabled Vehicle) . . . . . . . . . . . . . . . . . . . . . 155
Starting and Operating
New Vehicle Break-In . . . . . . . . . 156
Pedals . . . . . . . . . . . . . . . . . . . . . . . . 157
Ignition Positions . . . . . . . . . . . . . 157
Starting and Stopping theVehicle . . . . . . . . . . . . . . . . . . . . . . 159
Operating Temperature . . . . . . . 162
Winter Cover . . . . . . . . . . . . . . . . . 163 Engine Heater . . . . . . . . . . . . . . . . 163
Engine Alarm and Automatic
Shutdown . . . . . . . . . . . . . . . . . . . 164
Idle Shutdown . . . . . . . . . . . . . . . . 164
High Idle System . . . . . . . . . . . . . 165
Engine Checks Before Operating . . . . . . . . . . . . . . . . . . . 166
Parking over Things That Burn . . . . . . . . . . . . . . . . . . . 167
Engine Exhaust
Engine Exhaust . . . . . . . . . . . . . . 168
Running the Vehicle WhileParked . . . . . . . . . . . . . . . . . . . . . . 170
Diesel Particulate Filter
Diesel Particulate Filter . . . . . . . 171
Diesel Exhaust Fluid
Diesel Exhaust Fluid . . . . . . . . . . 180
Automatic Transmission
Automatic Transmission . . . . . . 196
Selector Lever . . . . . . . . . . . . . . . . 205
Overdrive Off . . . . . . . . . . . . . . . . . 206
Brakes
Antilock BrakeSystem (ABS) . . . . . . . . . . . . . . . 207
Parking Brake . . . . . . . . . . . . . . . . 211
Exhaust Brake . . . . . . . . . . . . . . . . 213
Cruise Control
Cruise Control . . . . . . . . . . . . . . . . 214
Fuel
Fuel for Diesel Engines . . . . . . . 218
Biodiesel . . . . . . . . . . . . . . . . . . . . . 219
Cold Weather Operation . . . . . . 221
Water in Fuel . . . . . . . . . . . . . . . . . 221
Running Out of Fuel . . . . . . . . . . 224
Filling the Tank . . . . . . . . . . . . . . . 225
Conversions and Add-Ons
Add-On Electrical Equipment . . . . . . . . . . . . . . . . . . 227
Power Take-Off (PTO) . . . . . . . . 227

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
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