brakes GMC SIERRA DENALI 2018 Service Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 341
Vehicle Care General Information General Information . . . . . . . . . . 342
California Proposition
65 Warning . . . . . . . . . . . . . . . . . 343
California Perchlorate
Materials Requirements . . . . . 343
Accessories and
Modifications . . . . . . . . . . . . . . . . 343
Vehicle Checks Doing Your Own
Service Work . . . . . . . . . . . . . . . 344
Hood . . . . . . . . . . . . . . . . . . . . . . . . . 344
Engine Compartment
Overview . . . . . . . . . . . . . . . . . . . . 345
Engine Oil . . . . . . . . . . . . . . . . . . . . 350
Engine Oil Life System . . . . . . . 353
Automatic Transmission Fluid
(6-Speed Transmission) . . . . . 354
Automatic Transmission Fluid
(8-Speed Transmission) . . . . . 357
Engine Air Cleaner/Filter . . . . . . 358
Cooling System . . . . . . . . . . . . . . 359
Engine Overheating . . . . . . . . . . 363
Overheated Engine Protection
Operating Mode . . . . . . . . . . . . . 364
Engine Fan . . . . . . . . . . . . . . . . . . . 365 Power Steering Fluid (1500
Series) . . . . . . . . . . . . . . . . . . . . . . 365
Power Steering Fluid (2500/
3500 Series) . . . . . . . . . . . . . . . . 365
Washer Fluid . . . . . . . . . . . . . . . . . 366
Brakes . . . . . . . . . . . . . . . . . . . . . . . 367
Brake Fluid . . . . . . . . . . . . . . . . . . . 368
Battery - North America . . . . . . 369
Four-Wheel Drive . . . . . . . . . . . . . 370
Front Axle . . . . . . . . . . . . . . . . . . . . 370
Rear Axle . . . . . . . . . . . . . . . . . . . . 371
Noise Control System . . . . . . . . 373
Starter Switch Check . . . . . . . . . 374
Automatic Transmission Shift
Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Ignition Transmission Lock
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Park Brake and P (Park)
Mechanism Check . . . . . . . . . . 375
Wiper Blade Replacement . . . . 375
Windshield Replacement . . . . . 376
Gas Strut(s) . . . . . . . . . . . . . . . . . . 376
Headlamp Aiming Headlamp Aiming . . . . . . . . . . . . 377
Bulb Replacement
Bulb Replacement . . . . . . . . . . . . 378
Halogen Bulbs . . . . . . . . . . . . . . . . 378 High Intensity Discharge (HID)
Lighting . . . . . . . . . . . . . . . . . . . . . 378
LED Lighting . . . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal,
Stoplamps, and Back-Up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Electrical System High Voltage Devices and
Wiring . . . . . . . . . . . . . . . . . . . . . . . 380
Electrical System Overload . . . 380
Fuses and Circuit Breakers . . . 381
Engine Compartment Fuse
Block . . . . . . . . . . . . . . . . . . . . . . . . 381
Instrument Panel Fuse Block
(Right) . . . . . . . . . . . . . . . . . . . . . . 385
Instrument Panel Fuse
Block (Left) . . . . . . . . . . . . . . . . . 386
Wheels and Tires Tires . . . . . . . . . . . . . . . . . . . . . . . . . . 389
All-Season Tires . . . . . . . . . . . . . . 389
Winter Tires . . . . . . . . . . . . . . . . . . 390
Low-Profile Tires . . . . . . . . . . . . . 390
All-Terrain Tires . . . . . . . . . . . . . . . 391
Tire Sidewall Labeling . . . . . . . . 391
Tire Designations . . . . . . . . . . . . . 393

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 343
California Proposition
65 Warning
{ WarningMost motor vehicles, including
this one, as well as many of its
service parts and fluids, contain
and/or emit chemicals known to
the State of California to cause
cancer and birth defects or other
reproductive harm. Engine
exhaust, many parts and
systems, many fluids, and some
component wear by-products
contain and/or emit these
chemicals. For more information
go to www.P65Warnings.ca.gov/
passenger-vehicle.
See Battery - North America 0 369
and Jump Starting - North America
0 426 and the back cover. California Perchlorate
Materials Requirements Certain types of automotive
applications, such as airbag
initiators, seat belt pretensioners,
and lithium batteries contained in
Remote Keyless Entry transmitters,
may contain perchlorate materials.
Special handling may be necessary.
For additional information, see
www.dtsc.ca.gov/hazardouswaste/
perchlorate.
Accessories and
Modifications Adding non-dealer accessories or
making modifications to the vehicle
can affect vehicle performance and
safety, including such things as
airbags, braking, stability, ride and
handling, emissions systems,
aerodynamics, durability, and
electronic systems like antilock
brakes, traction control, and stability
control. These accessories or
modifications could even cause
malfunction or damage not covered
by the vehicle warranty. Damage to suspension components
caused by modifying vehicle height
outside of factory settings will not be
covered by the vehicle warranty.
Damage to vehicle components
resulting from modifications or the
installation or use of non-GM
certified parts, including control
module or software modifications, is
not covered under the terms of the
vehicle warranty and may affect
remaining warranty coverage for
affected parts.
GM Accessories are designed to
complement and function with other
systems on the vehicle. See your
dealer to accessorize the vehicle
using genuine GM Accessories
installed by a dealer technician.
Also, see Adding Equipment to the
Airbag-Equipped Vehicle 0 90 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 367Caution.
Do not use washer fluid that
contains any type of water
repellent coating. This can
cause the wiper blades to
chatter or skip.
.
Do not use engine coolant
(antifreeze) in the
windshield washer. It can
damage the windshield
washer system and paint.
.
Do not mix water with
ready-to-use washer fluid.
Water can cause the
solution to freeze and
damage the washer fluid
tank and other parts of the
washer system.
.
When using concentrated
washer fluid, follow the
manufacturer instructions for
adding water.
.
Fill the washer fluid tank
only three-quarters full when
it is very cold. This allows
(Continued) Caution (Continued) for fluid expansion if
freezing occurs, which could
damage the tank if it is
completely full.
Brakes Disc brake pads have built-in wear
indicators that make a high-pitched
warning sound when the brake pads
are worn and new pads are needed.
The sound can come and go or be
heard all the time the vehicle is
moving, except when applying the
brake pedal firmly.
{ Warning
The brake wear warning sound
means that soon the brakes will
not work well. That could lead to
a crash. When the brake wear
warning sound is heard, have the
vehicle serviced. CautionContinuing to drive with worn-out
brake pads could result in costly
brake repair.
Some driving conditions or climates
can cause a brake squeal when the
brakes are first applied or lightly
applied. This does not mean
something is wrong with the brakes.
Properly torqued wheel nuts are
necessary to help prevent brake
pulsation. When tires are rotated,
inspect brake pads for wear and
evenly tighten wheel nuts in the
proper sequence to torque
specifications in Capacities and
Specifications 0 461 .
Brake linings should always be
replaced as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal
does not return to normal height,
or if there is a rapid increase in
pedal travel. This could be a sign
that brake service may be required.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
368 Vehicle Care Replacing Brake System Parts Always replace brake system parts
with new, approved replacement
parts. If this is not done, the brakes
may not work properly. The braking
performance expected can change
in many other ways if the wrong
replacement brake parts are
installed or parts are improperly
installed.
Brake Fluid
The brake master cylinder reservoir
is filled with DOT 3 brake fluid. See
Engine Compartment Overview
0 345 for the location of the
reservoir.
There are only two reasons why the
brake fluid level in the reservoir may
go down: .
Normal brake lining wear. When
new linings are installed, the
fluid level goes back up.
.
A fluid leak in the brake
hydraulic system. Have the
brake hydraulic system fixed.
With a leak, the brakes will not
work well.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
Do not top off the brake fluid.
Adding fluid does not correct a leak.
If fluid is added when the linings are
worn, there will be too much fluid
when new brake linings are
installed. Add or remove fluid, as
necessary, only when work is done
on the brake hydraulic system.
{ Warning
If too much brake fluid is added, it
can spill on the engine and burn,
if the engine is hot enough. You
or others could be burned, and
the vehicle could be damaged.
(Continued) Warning (Continued) Add brake fluid only when work is
done on the brake hydraulic
system.
When the brake fluid falls to a low
level, the brake warning light comes
on. See Brake System Warning
Light 0 152 .
Brake fluid absorbs water over time.
Replace brake fluid at the specified
intervals to prevent increased
stopping distance. See Maintenance
Schedule 0 448 .
Checking Brake Fluid Check brake fluid by looking at the
brake fluid reservoir. See Engine
Compartment Overview 0 345 .

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 409
{ Warning
Mixing tires of different sizes,
brands, or types may cause
loss of control of the vehicle,
resulting in a crash or other
vehicle damage. Use the
correct size, brand, and type
of tires on all wheels.
This vehicle may have a
different size spare than the
road tires originally installed
on the vehicle. When new, the
vehicle included a spare tire
and wheel assembly with a
similar overall diameter as the
road tires and wheels, so it is
all right to drive on it. The
spare tire was developed for
use on this vehicle and will not
affect vehicle handling. { Warning
Using bias-ply tires on the
vehicle may cause the wheel
rim flanges to develop cracks
after many miles of driving.
A tire and/or wheel could fail
suddenly and cause a crash.
Use only radial-ply tires with
the wheels on the vehicle.
Winter tires with the same speed
rating as the original equipment
tires may not be available for H,
V, W, Y and ZR speed rated
tires. Never exceed the winter
tires ’ maximum speed capability
when using winter tires with a
lower speed rating.
If the vehicle tires must be
replaced with a tire that does not
have a TPC Spec number, make
sure they are the same size,
load range, speed rating, and
construction (radial) as the
original tires. Vehicles that have a tire
pressure monitoring system
could give an inaccurate
low-pressure warning if non-TPC
Spec rated tires are installed.
See Tire Pressure Monitor
System 0 399 .
The Tire and Loading
Information label indicates the
original equipment tires on the
vehicle. See Vehicle Load Limits
0 248 for the label location and
more information about the Tire
and Loading Information label.
Different Size Tires and
Wheels If wheels or tires are installed that
are a different size than the original
equipment wheels and tires, vehicle
performance, including its braking,
ride and handling characteristics,
stability, and resistance to rollover
may be affected. If the vehicle has
electronic systems such as antilock
brakes, rollover airbags, traction
control, electronic stability control,

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Vehicle Care 413
Tire Chains
{ WarningIf the vehicle has dual wheels or
265/65R18, P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
LT275/65R18, P285/50R20,
285/45R22, or P285/45R22 size
tires, do not use tire chains. They
can damage the vehicle because
there is not enough clearance.
Tire chains used on a vehicle
without the proper amount of
clearance can cause damage to
the brakes, suspension, or other
vehicle parts. The area damaged
by the tire chains could cause you
to lose control of the vehicle and
you or others may be injured in a
crash.
Use another type of traction
device only if its manufacturer
recommends it for use on the
vehicle and tire size combination
(Continued) Warning (Continued) and road conditions. Follow that
manufacturer's instructions. To
help avoid damage to the vehicle,
drive slowly, readjust, or remove
the device if it is contacting the
vehicle, and do not spin the
vehicle's wheels.
If you do find traction devices that
will fit, install them on the rear
tires.
CautionIf the vehicle does not have dual
wheels and has a tire size other
than 265/65R18, P265/65R18,
P275/55R20, LT265/70R17,
LT265/70R18, LT265/60R20,
LT275/65R18, P285/50R20,
285/45R22, or P285/45R22, use
tire chains only where legal and
only when you must. Use chains
that are the proper size for the
(Continued) Caution (Continued) tires. Install them on the tires of
the rear axle. Do not use chains
on the tires of the front axle.
Tighten them as tightly as
possible with the ends securely
fastened. Drive slowly and follow
the chain manufacturer's
instructions. If you can hear the
chains contacting the vehicle,
stop and retighten them. If the
contact continues, slow down
until it stops. Driving too fast or
spinning the wheels with chains
on will damage the vehicle.
If a Tire Goes Flat It is unusual for a tire to blowout
while driving, especially if the tires
are maintained properly. If air goes
out of a tire, it is much more likely to
leak out slowly. But if there ever is a
blowout, here are a few tips about
what to expect and what to do:

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
446 Service and Maintenance
Service and
Maintenance General Information General Information . . . . . . . . . . 446
Maintenance Schedule Maintenance Schedule . . . . . . . 448
Special Application Services Special Application
Services . . . . . . . . . . . . . . . . . . . . 453
Additional Maintenance
and Care Additional Maintenance
and Care . . . . . . . . . . . . . . . . . . . . 453
Recommended Fluids,
Lubricants, and Parts Recommended Fluids and
Lubricants . . . . . . . . . . . . . . . . . . . 456
Maintenance Replacement
Parts . . . . . . . . . . . . . . . . . . . . . . . . 458
Maintenance Records
Maintenance Records . . . . . . . . 459 General Information This maintenance section applies to
vehicles with a gasoline engine. For
diesel engine vehicles, see
"Maintenance Schedule" in the
Duramax diesel supplement.
Your vehicle is an important
investment. This section describes
the required maintenance for the
vehicle. Follow this schedule to help
protect against major repair
expenses resulting from neglect or
inadequate maintenance. It may
also help to maintain the value of
the vehicle if it is sold. It is the
responsibility of the owner to have
all required maintenance performed.
Your dealer has trained technicians
who can perform required
maintenance using genuine
replacement parts. They have
up-to-date tools and equipment for
fast and accurate diagnostics. Many
dealers have extended evening and
Saturday hours, courtesy
transportation, and online
scheduling to assist with service
needs. Your dealer recognizes the
importance of providing
competitively priced maintenance
and repair services. With trained
technicians, the dealer is the place
for routine maintenance such as oil
changes and tire rotations and
additional maintenance items like
tires, brakes, batteries, and wiper
blades.
CautionDamage caused by improper
maintenance can lead to costly
repairs and may not be covered
by the vehicle warranty.
Maintenance intervals, checks,
inspections, recommended fluids,
and lubricants are important to
keep the vehicle in good working
condition.
Do not have chemical flushes that
are not approved by GM
performed on the vehicle. The
use of flushes, solvents, cleaners,
or lubricants that are not
(Continued)

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
454 Service and Maintenance Battery
The 12-volt battery supplies power
to start the engine and operate any
additional electrical accessories.
.
To avoid break-down or failure to
start the vehicle, maintain a
battery with full cranking power.
.
Trained dealer technicians have
the diagnostic equipment to test
the battery and ensure that the
connections and cables are
corrosion-free.
Belts
.
Belts may need replacing if they
squeak or show signs of
cracking or splitting.
.
Trained dealer technicians have
access to tools and equipment
to inspect the belts and
recommend adjustment or
replacement when necessary. Brakes
Brakes stop the vehicle and are
crucial to safe driving.
.
Signs of brake wear may include
chirping, grinding, or squealing
noises, or difficulty stopping.
.
Trained dealer technicians have
access to tools and equipment
to inspect the brakes and
recommend quality parts
engineered for the vehicle.
Fluids
Proper fluid levels and approved
fluids protect the vehicle ’ s systems
and components. See
Recommended Fluids and
Lubricants 0 456 for GM approved
fluids.
.
Engine oil and windshield
washer fluid levels should be
checked at every fuel fill.
.
Instrument cluster lights may
come on to indicate that fluids
may be low and need to be
filled. Hoses
Hoses transport fluids and should
be regularly inspected to ensure
that there are no cracks or leaks.
With a multi-point inspection, your
dealer can inspect the hoses and
advise if replacement is needed.
Lamps
Properly working headlamps,
taillamps, and brake lamps are
important to see and be seen on
the road.
.
Signs that the headlamps need
attention include dimming, failure
to light, cracking, or damage.
The brake lamps need to be
checked periodically to ensure
that they light when braking.
.
With a multi-point inspection,
your dealer can check the lamps
and note any concerns.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
474 Customer Information .
Vehicle make, model, and
model year
.
Vehicle Identification
Number (VIN)
.
Insurance company and policy
number
.
General description of the
damage to the other vehicle
Choose a reputable repair facility
that uses quality replacement parts.
See “ Collision Parts ” earlier in this
section.
If the airbag has inflated, see What
Will You See after an Airbag
Inflates? 0 82 .
Managing the Vehicle Damage
Repair Process In the event that the vehicle requires
damage repairs, GM recommends
that you take an active role in its
repair. If you have a pre-determined
repair facility of choice, take the
vehicle there, or have it towed there.
Specify to the facility that any
required replacement collision parts
be original equipment parts, either
new Genuine GM parts or recycled original GM parts. Remember,
recycled parts will not be covered by
the GM vehicle warranty.
Insurance pays the bill for the repair,
but you must live with the repair.
Depending on your policy limits,
your insurance company may
initially value the repair using
aftermarket parts. Discuss this with
the repair professional, and insist on
Genuine GM parts. Remember,
if the vehicle is leased, you may be
obligated to have the vehicle
repaired with Genuine GM parts,
even if your insurance coverage
does not pay the full cost.
If another party's insurance
company is paying for the repairs,
you are not obligated to accept a
repair valuation based on that
insurance company's collision policy
repair limits, as you have no
contractual limits with that company.
In such cases, you can have control
of the repair and parts choices as
long as the cost stays within
reasonable limits. Service Publications
Ordering Information Service Manuals Service Manuals have the diagnosis
and repair information on the
engines, transmission, axle,
suspension, brakes, electrical,
steering, body, etc.
Owner Information Owner publications are written
specifically for owners and intended
to provide basic operational
information about the vehicle. The
Owner ’ s Manual includes the
Maintenance Schedule for all
models.
In-Portfolio: Includes a Portfolio,
Owner ’ s Manual, and Warranty
Manual.
RETAIL SELL PRICE: $35.00 –
$40.00 (U.S.) plus handling and
shipping fees.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
492 Index Antilock Brake System
(ABS) (cont'd)
Warning Light . . . . . . . . . . . . . . . . . 152
Appearance Care
Exterior . . . . . . . . . . . . . . . . . . . . . . . 435
Interior . . . . . . . . . . . . . . . . . . . . . . . . 441
Apple CarPlay and
Android Auto . . . . . . . . . . . . . . . . . . 217
Assistance Program,
Roadside . . . . . . . . . . . . . . . . . . . . . . 469
Assistance Systems for
Driving . . . . . . . . . . . . . . . . . . . . . . . . 292
Assistance Systems for
Parking and Backing . . . . . . . . . . 289
Audio
Bluetooth . . . . . . . . . . . . . . . . . . . . . 204
Theft-Deterrent Feature . . . . . . . 187
Audio Players
CD . . . . . . . . . . . . . . . . . . . . . . . . . . . 195
Automatic
Dimming Mirrors . . . . . . . . . . . . . . . . 50
Door Locks . . . . . . . . . . . . . . . . . . . . . 41
Forward Braking . . . . . . . . . . . . . . 294
Headlamp System . . . . . . . . . . . . 179
Transmission . . . . . . . . . . . . . . . . . 265
Transmission Fluid . . . . . . 354, 357
Automatic Transmission
Manual Mode . . . . . . . . . . . . . . . . . 268 Automatic Transmission (cont'd)
Shift Lock Control Function
Check . . . . . . . . . . . . . . . . . . . . . . . 374
Auxiliary
Roof Mounted Lamp . . . . . . . . . . 182
Auxiliary Jack . . . . . . . . . . . . . . . . . . . 203
Avoiding Untrusted Media
Devices . . . . . . . . . . . . . . . . . . . . . . . 195
Axle, Front . . . . . . . . . . . . . . . . . . . . . . 370
Axle, Rear . . . . . . . . . . . . . . . . . . . . . . 371
B Battery
Exterior Lighting Battery
Saver . . . . . . . . . . . . . . . . . . . . . . . 185
Load Management . . . . . . . . . . . . 184
Power Protection . . . . . . . . . . . . . 185
Battery - North America . . . . 369, 426
Blade Replacement, Wiper . . . . . 375
Blind Spot Mirrors . . . . . . . . . . . . . . . 50
Bluetooth
Overview . . . . . . . . . . . . . . . . 211, 213
Bluetooth Audio . . . . . . . . . . . . . . . . 204
Brake
Pedal and Adjustable
Throttle . . . . . . . . . . . . . . . . . . . . . . 256
System Warning Light . . . . . . . . 152
Brakes . . . . . . . . . . . . . . . . . . . . . . . . . . 367 Brakes (cont'd)
Antilock . . . . . . . . . . . . . . . . . . . . . . . 280
Assist . . . . . . . . . . . . . . . . . . . . . . . . . 281
Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . 368
Parking . . . . . . . . . . . . . . . . . . . . . . . 281
Braking . . . . . . . . . . . . . . . . . . . . . . . . . 236
Automatic Forward . . . . . . . . . . . 294
Break-In, New Vehicle . . . . . . . . . . 255
Bulb Replacement
Center High-Mounted
Stoplamp (CHMSL) and
Cargo Lamp . . . . . . . . . . . . . . . . . 380
Halogen Bulbs . . . . . . . . . . . . . . . . 378
Headlamp Aiming . . . . . . . . . . . . . 377
Headlamps . . . . . . . . . . . . . . . . . . . 378
High Intensity Discharge
(HID) Lighting . . . . . . . . . . . . . . . 378
Taillamps, Turn Signal,
Stoplamps, and Back-up
Lamps . . . . . . . . . . . . . . . . . . . . . . 378
Buying New Tires . . . . . . . . . . . . . . . 408
C Calibration . . . . . . . . . . . . . . . . . . . . . . 131
California
Fuel Requirements . . . . . . . . . . . 300