brakes CHEVROLET LOW CAB FORWARD 2020 Owner's Guide

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
258 Vehicle Care
free of any type of damage. Check
the right front brake hose and pipe
in the same way. The rear left and
right brake hoses and pipes should
also be checked in the same
manner.
Disc Brakes and Drum Brakes
If the brake pads and shoe linings
wear out beyond their usable limit,
not only will the brake performance
be impaired, but brake components
could also fail.
{Warning
Do not drive with brake pads and
shoe linings worn out beyond the
limit. Excessively worn brake
pads and shoe linings may cause
breakdown of brake components
and poor braking performance.
You and others could be seriously
injured.
Caution
The pad has an embedded wear
indicator. A squeaking noise from
the indicator means that the pad
is approaching the usable limit.
If the squeaking noise from the
indicator can be heard, contact
the nearest dealer for inspection
or replacement.
Brake Fluid
Checking the Brake Fluid
Level
Remove the inspection cover (1) on
the left- hand side of the instrument
panel by turning it with your fingers.
Check that the fluid level in the
reservoir is between the "MAX" and
"ADD" lines.
If the fluid surface cannot easily be
seen, rock the vehicle gently.
Adding Brake Fluid
If the level of brake fluid has
dropped below the "ADD" line,
remove the cap (2) and add fluid.
Take care to avoid filling beyond the
"MAX" line.
Tighten the cap securely after the
fluid has been added.
When adding brake fluid to the tank,
take care to prevent dirt and water
from entering it. Any dirt or water in
the system could cause the vehicle
to lose braking functions.
Inspect and change brake fluid
according to the Maintenance
Schedule.
Use the recommended brake fluid
when adding brake fluid.

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
Vehicle Care 297
Tire Pressure
Tire Load and Inflation Table
Tire Load and Inflation Table
TIRES FOR VEHICLES IN HIGHWAY SERVICE
TIRE LOAD LIMITS AT VARIOUS COLD INFLATION PRESSURES
Tire Size Designation Cold Inflation Pressure (psi) 50 55 60 65 70 75 80 85 90 95
LT215/85R16E Dual Single(lbs) 2470
2680
225/70R19.5F Dual Single(lbs) 3115
33153245
34503415
3640
See Wheels and Tires 0285.
Tire Rotation
{Warning
Be sure to check the wheel studs,
wheel nuts and disc wheel for any
abnormality whenever the disc
wheel is removed.
(Continued)
Warning (Continued)
If you find any abnormal condition
on the wheel studs, wheel nuts or
disc wheel, do not continue to use
the wheel. Contact the nearest
dealer as soon as possible
Tires at different locations wear
differently. For uniform tire wear and
longer tire life, you should rotate the
tires on your vehicle regularly. Make sure to use tires of the same type
on the same axle. If you install tires
of different types on the same axle,
the vehicle may drift right or left
when you apply the brakes.
New tires are more likely to build up
heat and wear faster than old tires,
so they should be installed on the
front axle where the load is smaller.
If there is a difference in diameter
between the inner and outer tires of
a dual-tire wheel, install the smaller
diameter tire inside.

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
306 Vehicle Care
Front End Towing (All Wheels On
the Ground)
Your vehicle may be towed on all
wheels provided the steering is
operable. Remember that power
steering and brakes will not have
power assist. There must be a tow
bar installed between the tow
vehicle and the disabled vehicle.
Towing with all wheels on theground
1. Bumper
2. Tow Hook
3. Front Axle
4. Towing Guide
5. Towing Chain
To prepare a disabled vehicle for
front end towing with all wheels on
the ground, the following steps are
necessary:
.Block the rear wheels of the
disabled vehicle.
. Disconnect the driveshaft at the
rear axle. Secure the driveshaft
to the frame or crossmember.
When towing, disconnect the
driveshaft at the rear axle to ensure
the transmission is not damaged.
The rear end of the driveshaft must
be disconnected and safely secured
if the 80 km (50 mi) or 48 km/h
(30 mph) is exceeded.
Provide wood blocking to prevent
towing chains and bar from coming
into contact with the bumper.
If there is damage or suspected
damage to the rear axle, remove the
axle shafts.
Cover the hub openings to prevent
the loss of lubricant or entry of dirt
or foreign objects. After Towing
After towing the vehicle, block the
rear wheels and install axle shafts
or driveshaft.
Apply the parking brake before
disconnecting from the towing
vehicle. Check and fill rear axle with
oil, if required.
Rear End Towing
When towing a vehicle with rear
wheels raised, secure the steering
wheel to maintain straight-ahead
position. Make certain that the front
axle is not loaded beyond the front
axle gross axle weight rating
(GAWR) as indicated on the
vehicle's VIN and weight rating
plate.
Special Towing Instructions
1. All state and local laws regarding such items as
warning signals, night
illumination, speed, etc., must
be followed.
2. Safety chains must be used.

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
Service and Maintenance 327
Engine Coolant0243. Have the
Engine Coolant replaced by your
authorized dealer.
13. Exhaust System : Check the
complete exhaust system every
16 000 km (10,000 miles). Check
body areas near the exhaust
system. Look for broken, damaged,
missing, or out-of-position parts.
Also inspect for open seams, holes,
loose connections, or other
conditions which could cause heat
build-up at the rear body floor pan,
or could let exhaust fumes seep into
the passenger compartment. Dust
or water in the cabin may indicate a
leak in that area. Required repairs
should be made at once.
14. DPF (Clean Filter) : Clean the
filter every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first.
15. DPF (Pressure Difference
Sensor 0 Point Adjustment) :
Adjust the sensor every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first. 16. DPF (Pressure Difference
Sensor Hose) :
Inspect the sensor
hose every 160 000 km
(100,000 miles) or 3,000 hours
whichever occurs first. Replace the
sensor hose every 400 000 km
(250,000 miles).
17. Fuel Line System : Inspect the
fuel tank, cap and lines for damage
which could cause leakage every
16 000 km (10,000 miles). Inspect
fuel cap for correct sealing ability
and indications of physical damage.
Replace any damaged or
malfunctioning parts.
18. Brake Lining and Pad for
Wear : Check drum brake lining and
disc brake pad for wear or cracks
every 16 000 km (10,000 miles).
Check brakes (including parking
brake) more often if operating
conditions or driving habits result in
frequent braking.
Front disc brakes have built-in wear
noise indicators which are designed
to make a high pitched squeal or
cricket-like warning sound when the
brake pads are worn to the point
where new pads are needed. When the truck is in motion, the
sound may be constant or it may
come and go. Pressing the brake
pedal firmly may cause the sound
to stop.
Have the brake linings or the brake
pads replaced by your authorized
dealer as soon as possible after the
warning first becomes evident.
Failure to do so can result in
expensive damage to the brake
system or a serious crash.
19. Brake Drum and Rotor for
Wear and Damage :
Check brake
drums (rear and parking) and rotors
(front) for wear or damage every
32 000 km (20,000 miles) or
12 months whichever occurs first.
20. Brake Electric Vacuum Pump
(4500HD, 4500XD models) :
Inspect the brake electric vacuum
pump operation every 16 000 km
(10,000 miles) or 12 months,
whichever occurs first.

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
336 Service and Maintenance
Additional
Maintenance and Care
Owner Safety and Routine
Maintenance
Listed below are vehicle checks
which should be made periodically
by either the owner or a qualified
technician to ensure proper
performance and safety of your
vehicle. Take any problems promptly
to a technician for service advice.
For your safety and that of others,
any of the safety-related
components that may have been
damaged in a crash should be
checked and necessary repairs
performed before operating your
vehicle.
At the minimum, these routine
checks should be made every
6 months or 16,000 km
(10,000 miles), whichever comes
first. Whenever repairs are
necessary, have them completed
before operating the vehicle.A: Parking Brake :
Park on a fairly
steep hill and hold the vehicle with
the parking brake only. This checks
holding ability.
Before checking item (B) below, be
sure to have enough room around
the vehicle. Then firmly apply both
the parking brake see Parking
Brake 0211 and the regular brakes.
Do not use the accelerator pedal.
If the engine starts, be ready to turn
off the engine control switch at
once. Take these precautions
because the vehicle could move
without warning and possibly cause
injury or property damage.
B: Starter Safety Switch : Check
by trying to start the engine in each
gear. The starter should crank only
at selector position "P" or "N".
C: Transmission Shift Indicator :
Check that the indicator points to
the gear chosen.
D: Steering : Be alert for any
changes in steering action. An
inspection or service is needed
when: the steering wheel is harder to turn or has too much free play,
or when there are strange sounds
when turning or parking.
E: Wheel Alignment, Balance, and
Tires :
Check tires for abnormal
wear or damage. Also, check for
damaged wheels. A pull right or left
on a straight and level road may
show the need for a wheel
alignment. A vibration of the
steering wheel or seat at normal
highway speeds may mean a wheel
balancing is needed. Check tire
pressure when the tires are "cold,"
at least monthly, and whenever the
vehicle is serviced.
Check the pressure more often if
daily checks show it's needed.
(Refer to "Recommended Daily
(Pre-operation) Inspections" under
Owner Checks and Services 0330).
Change tire pressure as needed
when changing loads.
F: Brakes : Be alert to illumination
of the brake system warning light or
brake low vacuum warning light
(4500HD, 4500XD models) or the
tone alarm, or changes in braking
action, such as repeated pulling to

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
Service and Maintenance 337
one side, unusual sounds when
braking, increased brake pedal
travel or harder pedal. The front and
rear brakes are attached to an auto
adjuster mechanism. If there are no
defects, as the pedal travel is
properly maintained, adjustments
are not necessary. Check regularly
that the brake fluid reservoir
(left-hand side of the instrument
panel) or HBB reservoir (5500HD,
5500XD models: left side behind the
cab) is properly filled and check for
fluid leaks. Any of these conditions
could indicate the need for brake
system inspection and/or service.
G: Exhaust System :Be alert for
any changes in the sound of the
exhaust system or any smell of
fumes. These are signs the system
may be leaking. Have it checked
and/or repaired at once. (Refer to
"Engine Exhaust Emissions Caution
(Carbon Monoxide)" under Engine
Exhaust 0168).
H: Windshield Wipers and
Washers : Check operation and
condition of the wiper blades. Check
the flow of the washer spray. I: Defroster :
Turn the outlet
selector knob to "Defroster" and the
fan speed control knob to the fully
clockwise position. Then check the
airflow from the ducts at the inside
base of the windshield.
J: Rearview Mirrors and Sun
Visors : Check that friction joints
hold mirrors and sun visors in place.
K: Horn : Sound the horn, now and
then, to be sure it works.
L: Lap-Shoulder Belts : Check the
seat belt system (including webbing,
buckles, latch plates and anchors)
for proper operation, and for
damage.
M: Seat Adjusters : When
adjusting the driver's manual seat,
be sure the seat adjusters latch by
pushing the seat forward and
backward. Do not attempt to adjust
the seat when the vehicle is in
motion.
N: Lamps : Check panel lighting,
warning lamps, indicator lamps and
interior lamps. On the outside,
check: license plate lamps, side
marker lamps, reflectors on outside mirrors, headlamps, parking lamps,
identification and clearance lamps,
taillights, brake lamps, turn signals,
cornering lamps, backup lamps and
hazard warning flashers. Have
headlamp aim checked immediately
if beams seem improperly aimed.
O: Glass, Mirrors, Lights and/or
Reflectors Condition :
Look for
broken, scratched, dirty or damaged
glass, mirrors, lamps or reflectors
that could reduce the view or
visibility, or cause injury. Replace,
clean or repair promptly.
P: Door Latches : Check that doors
close, latch and lock tightly. Check
for broken, damaged or missing
parts that might prevent tight
latching.
Q :Tilt Cab (Driving Position) : Be
sure the tilt lever is down and
locked.
R: Fluid Leaks : Check for fuel,
water, oil or other fluid leaks by
looking at the surface beneath the
vehicle after it has been parked for

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
Technical Data 353
Disc Brakes
Model 4500HD 4500XD/5500HD/5500XD
Brake size (Diameter x
Thickness) φ293 x 40 mm (φ11.54 x 1.57 in)
φ363 x 42 mm (φ14.29 x 1.65 in)
Rotor thickness [Standard Value] 40.0 mm (1.575 in) 42.0 mm (1.654 in)
[Usable Limit] 37.0 mm (1.457 in) 39.0 mm (1.535 in)
Pad thickness [Standard Value] 13.0 mm (0.512 in) 13.0 mm (0.512 in)
[Usable Limit] 1.0 mm (0.04 in) 1.0 mm (0.04 in) Service Brakes
Brake pedal free play 4500HD/4500XD 5–10 mm (0.20–0.39 in)
5500HD/5500XD 5–10 mm (0.20–0.39 in)
Clearance between the brake pedal and the brake pedal bracket with a pressure of 490 Y(50 kgf/110 lb ft)
applied to the brake pedal
4500HD/4500XD models 35 mm (1.38 in) or more
Clearance between the brake pedal and the brake pedal bracket with a pressure of 294 Y(30 kgf/66 lb ft) applied
to the brake pedal
5500HD/5500XD models 35 mm (1.38 in) or more

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
362 Customer Information
Publication Ordering
Information
Service Manuals
Service manuals have the diagnosis
and repair information on the
engine, transmission, axle,
suspension, brakes, electrical
system, steering system, body, etc.
Customer Literature
Owner’s manuals are written
specifically for owners and are
intended to provide basic
operational information about the
vehicle. The owner ’s manual
includes the Maintenance Schedule
for all models.
Customer literature publications
available for purchase include
owner ’s manuals, warranty
manuals, infotainment manuals, and
portfolios. Portfolios include an
owner ’s manual, warranty manual,
infotainment manual, if applicable,
and zip lock bag or pouch.
Current and Past Models
Service manuals and customer
literature are available for many
current and past model year GM
vehicles.
To order, call 1-800-551-4123
Monday–Friday, 8:00 a.m.–6:00 p.m.
eastern time
For credit card orders only (VISA,
MasterCard, or Discover), see
Helm, Inc. at: www.helminc.com.
To order by mail, write to:
Helm, Incorporated
Attention: Customer Service
47911 Halyard Drive
Plymouth, MI 48170
Make checks payable in U.S. funds.
Radio Frequency
Statement
This vehicle has systems that
operate on a radio frequency that
complies with Part 15 of the Federal
Communications Commission (FCC)
rules. Operation is subject to the following
two conditions:
1. The device may not cause harmful interference.
2. The device must accept any interference received, including
interference that may cause
undesired operation of the
device.
Changes or modifications to any of
these systems by other than an
authorized service facility could void
authorization to use this equipment.

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
366 Index
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 253Antilock . . . . . . . . . . . . . . . . . . . . . . . 207
Exhaust Light . . . . . . . . . . . . . . . . . . . 65
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 258
Parking . . . . . . . . . . . . . . . . . . . . . . . .211
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 134
Break-In, New Vehicle . . . . . . . . . . 156
Bulb Replacement Headlamp Aiming . . . . . . . . . . . . . 267
Headlamps . . . . . . . . . . . . . . . . . . . 267
Headlamps and Front TurnSignal . . . . . . . . . . . . . . . . . . . . . . . 270
Interior Lamps . . . . . . . . . . . . . . . . 277
License Plate Lamps . . . . . . . . . 276
Roofmarker Lamps . . . . . . . . . . . 274
Sidemarker Lamps . . . . . . . . . . . 274
Taillamps, Turn Signal, Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 276
Buzzers, Warning . . . . . . . . . . . . . . . . 79
C
Cab Tilting . . . . . . . . . . . . . . . . . . . . . . 233
California Perchlorate MaterialsRequirements . . . . . . . . . . . . . . . 230 California
Proposition
65 Warning . . . . . . . . . .230, 259, 301,
Back Cover
Capacities and Specifications . . . . . . . . . . . . . . . . . 349
Carbon Monoxide
Engine Exhaust . . . . . . . . . . . . . . . 168
Winter Driving . . . . . . . . . . . . . . . . 142
Cargo Lamp . . . . . . . . . . . . . . . . . . . . . 84
Caution, Danger, and Warning . . . . 3
CD Player . . . . . . . . . . . . . . . . . . . . . . . 90
Check Engine Light (MalfunctionIndicator) . . . . . . . . . . . . . . . . . . . . . . 61
Child Restraints
Systems . . . . . . . . . . . . . . . . . . . . . . . . 39
Cleaning Exterior Care . . . . . . . . . . . . . . . . . 307
Interior Care . . . . . . . . . . . . . . . . . . 313
Climate Control Systems . . . . . . . 121
Air Conditioning . . . . . . . . . . . . . . 121
Heating . . . . . . . . . . . . . . . . . . . . . . . 121
Cluster, Instrument . . . . . . . . . . . . . . 57
Cold Weather Operation . . . . . . . . 221
Collision Damage Repair . . . . . . . 359 Compartments
Storage . . . . . . . . . . . . . . . . . . . . . . . . . 42
Control of a Vehicle . . . . . . . . . . . . . 130
Coolant Engine . . . . . . . . . . . . . . . . . . . . . . . . 243
Engine Temperature Gauge . . . . 60
Cooling . . . . . . . . . . . . . . . . . . . . . . . . . 121
Cornering Lamps . . . . . . . . . . . . . . . . 83
Cover
Engine . . . . . . . . . . . . . . . . . . . . . . . . 235
Covers
Winter . . . . . . . . . . . . . . . . . . . . . . . . 163
Cruise Control . . . . . . . . . . . . . . . . . . 214 Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Cupholders . . . . . . . . . . . . . . . . . . . . . . 44
Customer Assistance . . . . . . . . . . . 357 Offices . . . . . . . . . . . . . . . . . . . . . . . . 357
Text Telephone (TTY)Users . . . . . . . . . . . . . . . . . . . . . . . 357
Customer Information Publications Ordering
Information . . . . . . . . . . . . . . . . . . 362
Customer Satisfaction Procedure . . . . . . . . . . . . . . . . . . . . . 356
Cybersecurity . . . . . . . . . . . . . . . . . . . 364

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
Index 367
D
Damage Repair, Collision . . . . . . . 359
Danger, Warning, and Caution . . . . 3
Daytime Running Lamps (DRL)Indicator Light . . . . . . . . . . . . . . . . . . 69
Devices Auxiliary . . . . . . . . . . . . . . . . . . . . . . 107
Diesel Engine Engine Alarm andAutomatic Shutdown . . . . . . . . 164
Diesel Exhaust Fluid . . . . . . . . . . . . 180
Diesel Exhaust Fluid (DEF) Gauge . . . . . . . . . . . . . . . . . . . . . . . . . 60
Diesel Exhaust Fluid (DEF)
Warning Light . . . . . . . . . . . . . . . . . . 68
Diesel Particulate Filter . . . . . . . . . 171
Distracted Driving . . . . . . . . . . . . . . . 130
Dome Lamps . . . . . . . . . . . . . . . . . . . . 84
Door Locks . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Power Locks . . . . . . . . . . . . . . . . . . . . 21
Drive Belt Routing, Engine . . . . . . 355
Driver Behavior . . . . . . . . . . . . . . . . . 129
Driver Information Center (DIC) . . . . . . . . . . . . . . . . . . . 70
Driving Better Fuel Economy . . . . . . . . . 129
Emergencies . . . . . . . . . . . . 145, 155 Driving (cont'd)
Hill and Mountain Roads . . . . . . 141
If the Vehicle is Stuck . . . . . . . . . 144
Wet Roads . . . . . . . . . . . . . . . . . . . 140
Winter . . . . . . . . . . . . . . . . . . . . . . . . 142
E
Electrical Equipment,
Add-On . . . . . . . . . . . . . . . . . . . . . . . 227
Electrical System
Overload . . . . . . . . . . . . . . . . . . . . . 277
Emergencies . . . . . . . . . . . . . . 145, 155
Engine Air Cleaner/Filter . . . . . . . . . . . . . 243
Alarm and Automatic
Shutdown . . . . . . . . . . . . . . . . . . . 164
Check Light (Malfunction Indicator) . . . . . . . . . . . . . . . . . . . . . . 61
Checks Before Operating . . . . . 166
Compartment Overview . . . . . . . 234
Coolant . . . . . . . . . . . . . . . . . . . . . . . 243
Coolant Temperature Gauge . . . . 60
Cover . . . . . . . . . . . . . . . . . . . . . . . . . 235
Drive Belt Routing . . . . . . . . . . . . 355
Exhaust . . . . . . . . . . . . . . . . . . . . . . 168
Heater . . . . . . . . . . . . . . . . . . . . . . . . 163
High Idle System . . . . . . . . . . . . . 165
Oil Pressure Light . . . . . . . . . . . . . . 67 Engine (cont'd)
Overheating . . . . . . . . . . . . . . . . . . 249
Reduced Power Light . . . . . . . . . . . 69
Running While Parked . . . . . . . . 170
Shutdown Warning Light . . . . . . . . 68
Engine Oil Level Indicator Light . . . . . . . . . . . . 67
Engines Diesel Fuel . . . . . . . . . . . . . . . . . . . 218
Exhaust Brake . . . . . . . . . . . . . . . . . . 213
Exhaust Brake Light . . . . . . . . . . . . . 65
Exhaust Fluid Diesel . . . . . . . . . . . . . . . . . . . . . . . . 180
Extender, Seat Belt . . . . . . . . . . . . . . 37
Exterior Lamp Controls . . . . . . . . . . 80
F
Filter . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Fuel . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Filter, Engine Air Cleaner . . . . . . . . . . . 243
Fixed Mast Antenna . . . . . . . . . . . . . 90
Flash-to-Pass . . . . . . . . . . . . . . . . . . . . 81
Flashers, Hazard Warning . . . . . . . 82
Flat Tire . . . . . . . . . . . . . . . . . . . . . . . . 300
Fluid Automatic Transmission . . . . . . 241
Brakes . . . . . . . . . . . . . . . . . . . . . . . . 258