2021 GMC SIERRA brake

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
412 Service and Maintenance
Additional Required ServicesMaintenance Schedule Additional
Required Services - Normal
12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires and/or boots.
(2.7L L4 Turbo Engine Only)@ @
Change transfer case fluid, if equipped with 4WD. (4)@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Service and Maintenance 413
Footnotes—Maintenance Schedule
Additional Required Services - Normal
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 334.
(2) Or every two years, whichever comes
first. More frequent replacement may be
needed if the vehicle is driven in areas with
heavy traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter replacement
may also be needed if you notice reduced
airflow, windows fogging up, or odors. Your
local GM Service location can help you
determine when it is the right time to
replace your filter.
(3) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced. (5)
Or every five years, whichever comes
first. See Cooling System 0335.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0343.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0348.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0349.
(10) Replace air conditioning desiccant every
seven years.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
414 Service and Maintenance
Maintenance Schedule Additional
Required Services - Severe12 000 km/7,500 mi
24 000 km/15,000 mi
36 000 km/22,500 mi
48 000 km/30,000 mi 60 000 km/37,500 mi
72 000 km/45,000 mi84 000 km/52,500 mi
96 000 km/60,000 mi
108 000 km/67,500 mi 120 000 km/75,000 mi 132 000 km/82,500 mi
144 000 km/90,000 mi 156 000 km/97,500 mi
168 000 km/105,000 mi 180 000 km/112,500 mi
192 000 km/120,000 mi 204 000 km/127,500 mi 216 000 km/135,000 mi
228 000 km/142,500 mi
240 000 km/150,000 mi
Rotate tires and perform Required Services. Check engine oil
level and oil life percentage. Change engine oil and filter,
if needed.
Check engine air filter life percentage and status. Change
engine air filter, if needed. (1)
@ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @
Replace passenger compartment air filter. (2)@ @@@@@
Inspect evaporative control system. (3)@ @@
Replace spark plugs. Inspect spark plug wires and/or boots.
(Except 2.7L L4 Turbo Engine)@
Replace spark plugs. Inspect spark plug wires and/or boots.
(2.7L L4 Turbo Engine Only)@ @
Change automatic transmission fluid and filter.@@@
Change transfer case fluid, if equipped with 4WD. (4)@@@
Drain and fill engine cooling system. (5)@
Visually inspect accessory drive belts. (6)@
Replace brake fluid. (7)
Replace windshield wiper blades. (8)
@ @ @ @ @ @ @ @ @ @
Replace hood gas struts and tailgate dampener. (9)@ @
Replace air conditioning desiccant. (10)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Service and Maintenance 415
Footnotes—Maintenance Schedule
Additional Required Services - Severe
(1) Or every four years, whichever comes
first. If driving in dusty conditions, inspect
the filter at each oil change or more often
as needed. See Engine Air Cleaner/Filter
0 334.
(2) Or every two years, whichever comes
first. More frequent replacement may be
needed if the vehicle is driven in areas with
heavy traffic, poor air quality, areas with
high dust levels or are sensitive to
environmental allergens. Filter replacement
may also be needed if you notice reduced
airflow, windows fogging up, or odors. Your
local GM Service location can help you
determine when it is the right time to
replace your filter.
(3) Visually check all fuel and vapor lines
and hoses for proper attachment,
connection, routing, and condition.
(4) Do not directly power wash the transfer
case and/or front/rear axle output seals.
High pressure water can overcome the seals
and contaminate the fluid. Contaminated
fluid will decrease the life of the transfer
case and/or drive axles and should be
replaced. (5)
Or every five years, whichever comes
first. See Cooling System 0335.
(6) Or every 10 years, whichever comes first.
Inspect for fraying, excessive cracking,
or damage; replace, if needed.
(7) Replace brake fluid every five years. See
Brake Fluid 0343.
(8) Or every 12 months, whichever comes
first. See Wiper Blade Replacement 0348.
(9) Or every 10 years, whichever comes first.
See Gas Strut(s) 0349.
(10) Replace air conditioning desiccant every
seven years.
Special Application Services
.Severe Commercial Use Vehicles Only:
Lubricate chassis components every oil
change.
.Have underbody flushing service
performed. See "Underbody Maintenance"
in Exterior Care 0398.
Additional Maintenance
and Care
Your vehicle is an important investment and
caring for it properly may help to avoid
future costly repairs. To maintain vehicle
performance, additional maintenance
services may be required.
It is recommended that your dealer perform
these services —their trained dealer
technicians know your vehicle best. Your
dealer can also perform a thorough
assessment with a multi-point inspection to
recommend when your vehicle may need
attention.
The following list is intended to explain the
services and conditions to look for that may
indicate services are required.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
416 Service and Maintenance
.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 0418 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.
Shocks and Struts
Shocks and struts help aid in control for a
smoother ride.
.Signs of wear may include steering wheel
vibration, bounce/sway while braking,
longer stopping distance, or uneven
tire wear.
.As part of the multi-point inspection,
trained dealer technicians can visually
inspect the shocks and struts for signs of
leaking, blown seals, or damage, and can
advise when service is needed.
Tires
Tires need to be properly inflated, rotated,
and balanced. Maintaining the tires can save
money and fuel, and can reduce the risk of
tire failure.
.Signs that the tires need to be replaced
include three or more visible treadwear
indicators; cord or fabric showing through
the rubber; cracks or cuts in the tread or
sidewall; or a bulge or split in the tire.
.Trained dealer technicians can inspect and
recommend the right tires. Your dealer
can also provide tire/wheel balancing
services to ensure smooth vehicle
operation at all speeds. Your dealer sells
and services name brand tires.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
418 Service and Maintenance
Recommended Fluids, Lubricants, and Parts
Recommended Fluids and Lubricants
This maintenance section applies to vehicles with a gasoline engine. If the vehicle has a diesel engine, see“Recommended Fluids and Lubricants”
in the Duramax diesel supplement.
Fluids and lubricants identified below by name or specification, including fluids or lubricants not listed here, can be obtained from your dealer.
Usage Fluid/Lubricant
Automatic Transmission (6-Speed Transmission) DEXRON-VI Automatic Transmission Fluid.
Automatic Transmission (8-Speed Transmission) DEXRON-HP Automatic Transmission Fluid.
Automatic Transmission (10-Speed Transmission) DEXRON ULV Automatic Transmission Fluid.
Chassis Lubrication Chassis lubricant meeting requirements of NLGI #2, Category LB or GC-LB. Engine Coolant 50/50 mixture of clean, drinkable water and use only DEX-COOL coolant. See Cooling System
0 335.
Engine Oil Engine oil meeting the dexos1 specification of the proper SAE viscosity grade. ACDelco dexos1 full synthetic is recommended. See Engine Oil0330.
Front and Rear Axle Driveshaft Splines See your dealer.
Front Axle (Four-Wheel Drive) and Rear Axle See your dealer. Hydraulic Brake System DOT 4 Hydraulic Brake Fluid. See Brake Fluid0343.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Customer Information 435
coverage is not available from your current
insurance carrier, consider switching to
another insurance carrier.
If the vehicle is leased, the leasing company
may require you to have insurance that
ensures repairs with Genuine GM Original
Equipment Manufacturer (OEM) parts or
Genuine Manufacturer replacement parts.
Read the lease carefully, as you may be
charged at the end of the lease for poor
quality repairs.
If a Crash Occurs
If there has been an injury, call emergency
services for help. Do not leave the scene of
a crash until all matters have been taken
care of. Move the vehicle only if its position
puts you in danger, or you are instructed to
move it by a police officer.
Give only the necessary information to
police and other parties involved in the
crash.
For emergency towing seeRoadside
Assistance Program 0431.
Gather the following information:
.Driver name, address, and telephone
number
.Driver license number
.Owner name, address, and telephone
number
.Vehicle license plate number
.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? 065.
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.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
438 Customer Information
Cybersecurity
GM collects information about the use of
your vehicle including operational and safety
related information. We collect this
information to provide, evaluate, improve,
and troubleshoot our products and services
and to develop new products and services.
The protection of vehicle electronics systems
and customer data from unauthorized
outside electronic access or control is
important to GM. GM maintains appropriate
security standards, practices, guidelines and
controls aimed at defending the vehicle and
the vehicle service ecosystem against
unauthorized electronic access, detecting
possible malicious activity in related
networks, and responding to suspected
cybersecurity incidents in a timely,
coordinated and effective manner. Security
incidents could impact your safety or
compromise your private data. To minimize
security risks, please do not connect your
vehicle electronic systems to unauthorized
devices or connect your vehicle to any
unknown or untrusted networks (such as
Bluetooth, WIFI or similar technology). In
the event you suspect any security incident
impacting your data or the safe operation of
your vehicle, please stop operating your
vehicle and contact your dealer.
Event Data Recorders
This vehicle is equipped with an event data
recorder (EDR). The main purpose of an EDR
is to record, in certain crash or near
crash-like situations, such as an air bag
deployment or hitting a road obstacle, data
that will assist in understanding how a
vehicle’s systems performed. The EDR is
designed to record data related to vehicle
dynamics and safety systems for a short
period of time, typically 30 seconds or less.
The EDR in this vehicle is designed to record
such data as:
.How various systems in your vehicle were
operating;
.Whether or not the driver and passenger
safety belts were buckled/fastened;
.How far (if at all) the driver was
depressing the accelerator and/or brake
pedal; and,
.How fast the vehicle was traveling.
These data can help provide a better
understanding of the circumstances in which
crashes and injuries occur.
Note
EDR data are recorded by your vehicle only
if a non-trivial crash situation occurs; no
data are recorded by the EDR under normal driving conditions and no personal data
(e.g., name, gender, age, and crash location)
are recorded. However, other parties, such
as law enforcement, could combine the EDR
data with the type of personally identifying
data routinely acquired during a crash
investigation.
To read data recorded by an EDR, special
equipment is required, and access to the
vehicle or the EDR is needed. In addition to
the vehicle manufacturer, other parties, such
as law enforcement, that have the special
equipment, can read the information if they
have access to the vehicle or the EDR.
GM will not access these data or share it
with others except: with the consent of the
vehicle owner or, if the vehicle is leased,
with the consent of the lessee; in response
to an official request by police or similar
government office; as part of GM's defense
of litigation through the discovery process;
or, as required by law. Data that GM collects
or receives may also be used for GM
research needs or may be made available to
others for research purposes, where a need
is shown and the data is not tied to a
specific vehicle or vehicle owner.