Page 457 of 594

Black plate (33,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-33
Checking Brake Fluid
Check brake fluid by looking at the
brake fluid reservoir. SeeEngine
Compartment Overview on
page 10‑6.
The fluid level should be above
MIN. If it is not, have the brake
hydraulic system checked to see
if there is a leak. After work is done on the brake
hydraulic system, make sure the
level is above the MIN but not
over the MAX mark.
What to Add
Use only new DOT 3 brake
fluid from a sealed container.
See
Recommended Fluids and
Lubricants on page 11‑8.
Always clean the brake fluid
reservoir cap and the area around
the cap before removing it.
This helps keep dirt from
entering the reservoir.
{WARNING
With the wrong kind of fluid in
the brake hydraulic system,
the brakes might not work well.
This could cause a crash. Always
use the proper brake fluid. Notice:
.Using the wrong fluid
can badly damage brake
hydraulic system parts.
For example, just a few
drops of mineral-based oil,
such as engine oil, in the
brake hydraulic system can
damage brake hydraulic
system parts so badly that
they will have to be replaced.
Do not let someone put in
the wrong kind of fluid.
.If brake fluid is spilled on the
vehicle's painted surfaces,
the paint finish can be
damaged. Be careful not
to spill brake fluid on the
vehicle. If you do, wash it
off immediately.
Page 458 of 594

Black plate (34,1)GMC Sierra Owner Manual - 2011
10-34 Vehicle Care
Battery
If the vehicle is a Hybrid, see
the Hybrid Supplement for more
information.
This vehicle has a maintenance free
battery (or batteries). Refer to the
replacement number on the original
battery label when a new battery is
needed. SeeEngine Compartment
Overview on page 10‑6 for battery
location.
{DANGER
Battery posts, terminals, and
related accessories contain lead
and lead compounds, chemicals
known to the State of California
to cause cancer and reproductive
harm. Wash hands after handling.
Vehicle Storage
{WARNING
Batteries have acid that can burn
you and gas that can explode.
You can be badly hurt if you are
not careful. See Jump Starting on
page 10‑98 for tips on working
around a battery without
getting hurt.
Infrequent Usage: Remove the
black, negative (−) cable from the
battery to keep the battery from
running down.
Extended Storage: Remove the
black, negative (−) cable from the
battery or use a battery trickle
charger.
Four-Wheel Drive
Transfer Case
When to Check Lubricant
Refer to Scheduled Maintenance on
page 11‑2 to determine when to
check the lubricant.
How to Check Lubricant
Electric Shift Transfer Case
A. Fill Plug
B. Drain Plug
Page 459 of 594
Black plate (35,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-35
Manual Shift Transfer Case
A. Fill Plug
B. Drain PlugActive Transfer Case
A. Fill Plug
B. Drain Plug
To get an accurate reading, the
vehicle should be on a level
surface. If the level is below the bottom of
the fill plug hole, located on the
transfer case, some lubricant will
need to be added. Add enough
lubricant to raise the level to the
bottom of the fill plug hole. Use
care not to overtighten the plug.
When to Change Lubricant
Refer to
Scheduled Maintenance on
page 11‑2 to determine how often to
change the lubricant.
What to Use
Refer to Recommended Fluids
and Lubricants on page 11‑8 to
determine what kind of lubricant
to use.
Page 460 of 594
Black plate (36,1)GMC Sierra Owner Manual - 2011
10-36 Vehicle Care
Front Axle
When to Check and Change
Lubricant
It is not necessary to regularly
check front axle fluid unless a leak
is suspected, or an unusual noise is
heard. A fluid loss could indicate a
problem. Have it inspected and
repaired.
How to Check Lubricant
To get an accurate reading, the
vehicle should be on a level
surface.
1500 Series
A. Fill Plug
B. Drain PlugAll Except 1500 Series
A. Fill Plug
B. Drain Plug
.When the differential is cold,
add enough lubricant to raise the
level from 0 mm (0 in) to 3.2 mm
(1/8 in) below the fill plug hole.
.When the differential is at
operating temperature (warm),
add enough lubricant to raise
the level to the bottom of the fill
plug hole.
Page 461 of 594

Black plate (37,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-37
What to Use
Refer toRecommended Fluids
and Lubricants on page 11‑8 to
determine what kind of lubricant
to use.
Rear Axle
When to Check Lubricant
It is not necessary to regularly
check rear axle fluid unless a leak
is suspected or an unusual noise
is heard. A fluid loss could indicate
a problem. Have it inspected and
repaired.
All axle assemblies are filled by
volume of fluid during production.
They are not filled to reach a
certain level. When checking the
fluid level on any axle, variations
in the readings can be caused by
factory fill differences between the
minimum and the maximum fluid
volume. Also, if a vehicle has just
been driven before checking the
fluid level, it may appear lower than normal because fluid has traveled
out along the axle tubes and has
not drained back to the sump
area. Therefore, a reading taken
five minutes after the vehicle has
been driven will appear to have a
lower fluid level than a vehicle that
has been stationary for an hour or
two. Remember that the rear axle
assembly must be supported to
get a true reading.
How to Check Lubricant
2500HD with 6.0 L
All Other Series and Engines
To get an accurate reading, the
vehicle should be on a level
surface.
.For all 4.3 L, 4.8 L and 5.3 L
1500 Series applications,
the proper level is 1.0 mm to
19.0 mm (0.04 in to 0.7 in)
below the bottom of the fill
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
Page 462 of 594

Black plate (38,1)GMC Sierra Owner Manual - 2011
10-38 Vehicle Care
.For all 6.0 L and 6.2 L 1500
Series applications, the proper
level is from 15 mm to 40 mm
(0.6 in to 1.6 in) below the
bottom of the fill plug hole,
located on the rear axle.
Add only enough fluid to
reach the proper level.
.For all 6.0 L 2500HD Series
applications, the proper level is
from 0 mm to 13 mm (0 to 0.5 in)
below the bottom of the fill plug
hole, located on the rear axle.
Add only enough fluid to reach
the proper level.
.For all 6.6 L Duramax Diesel
2500HD Series applications and
all 3500 Series applications, the
proper level is from 17 mm to
21 mm (0.6 in to 0.8 in) below
the bottom of the fill plug hole,
located on the rear axle. Add
only enough fluid to reach the
proper level.
What to Use
Refer toRecommended Fluids
and Lubricants on page 11‑8 to
determine what kind of lubricant
to use.
Noise Control System
The following information relates
to compliance with federal noise
emission standards for vehicles
with a Gross Vehicle Weight Rating
(GVWR) of more than 4 536 kg
(10,000 lbs). The Scheduled
Maintenance on page 11‑2 provides
information on maintaining the
noise control system to minimize
degradation of the noise emission
control system during the life of your
vehicle. The noise control system
warranty is given in your warranty
booklet. These standards apply only to
vehicles sold in the United States.
Federal law prohibits the following
acts or the causing thereof:
1. The removal or rendering
inoperative by any person,
other than for purposes
of maintenance, repair or
replacement, of any device or
element of design incorporated
into any new vehicle for the
purpose of noise control, prior to
its sale or delivery to the ultimate
purchaser or while it is in use; or
2. The use of the vehicle after such device or element of
design has been removed or
rendered inoperative by any
person.
Page 463 of 594

Black plate (39,1)GMC Sierra Owner Manual - 2011
Vehicle Care 10-39
Among those acts presumed to
constitute tampering are the acts
listed below.
Insulation:
Removal of the noise shields or any
underhood insulation.
Engine:
Removal or rendering engine speed
governor, if the vehicle has one,
inoperative so as to allow engine
speed to exceed manufacturer
specifications.
Fan and Drive:
.Removal of fan clutch, if the
vehicle has one, or rendering
clutch inoperative.
.Removal of the fan shroud, if the
vehicle has one.
Air Intake:
.Removal of the air cleaner
silencer.
.Modification of the air cleaner. Exhaust:
.Removal of the muffler and/or
resonator.
.Removal of the exhaust pipes
and exhaust pipe clamps.
Starter Switch Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. 2. Firmly apply both the parking
brake and the regular brake.
See Parking Brake on
page 9‑69.
Do not use the accelerator
pedal, and be ready to turn off
the engine immediately if it
starts.
3. Try to start the engine in each gear. The vehicle should start
only in P (Park) or N (Neutral).
If the vehicle starts in any other
position, contact your dealer for
service.
Page 464 of 594

Black plate (40,1)GMC Sierra Owner Manual - 2011
10-40 Vehicle Care
Automatic Transmission
Shift Lock Control
Function Check
{WARNING
When you are doing this
inspection, the vehicle could
move suddenly. If the vehicle
moves, you or others could be
injured.
1. Before starting this check, be sure there is enough room
around the vehicle. It should
be parked on a level surface.
2. Firmly apply the parking brake. See Parking Brake on
page 9‑69.
Be ready to apply the regular
brake immediately if the vehicle
begins to move. 3. With the engine off, turn the
ignition on, but do not start the
engine. Without applying the
regular brake, try to move the
shift lever out of P (Park) with
normal effort. If the shift lever
moves out of P (Park), contact
your dealer for service.
Ignition Transmission
Lock Check
While parked, and with the parking
brake set, try to turn the ignition
to LOCK/OFF in each shift lever
position.
.The ignition should turn to
LOCK/OFF only when the
shift lever is in P (Park).
.The ignition key should come
out only in LOCK/OFF.
Contact your dealer if service is
required.
Park Brake and P (Park)
Mechanism Check
{WARNING
When you are doing this check,
the vehicle could begin to move.
You or others could be injured
and property could be damaged.
Make sure there is room in front
of the vehicle in case it begins to
roll. Be ready to apply the regular
brake at once should the vehicle
begin to move.