2001 GMC SIERRA Maintenance

6-32
Automatic Transfer Case
If the level is below the bottom of the filler plug hole,
you'll need to add some lubricant. Add enough lubricant
to raise the level to the bottom of the filler plug hole.
Use care not to overtighten plug.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids
and Lubricantsº in the Index.
Front Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªScheduled
Maintenance Servicesº in the Index.
How to Check Lubricant
If the level is below the bottom of the filler plug hole,
you may need to add some lubricant.

6-33
When the differential is cold, add enough lubricant
to raise the level to 1/2 inch (12 mm) below the filler
plug hole.
When the differential is at operating temperature
(warm), add enough lubricant to raise the level to the
bottom of the filler plug hole.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids
and Lubricantsº in the Index.
Engine Coolant
The cooling system in your vehicle is filled with
DEX
-COOL engine coolant. This coolant is designed
to remain in your vehicle for 5 years or 150,000 miles
(240 000 km), whichever occurs first, if you add only
DEX
-COOL extended life coolant.
The following explains your cooling system and how
to add coolant when it is low. If you have a problem
with engine overheating, see ªEngine Overheatingº in
the Index.A 50/50 mixture of clean, drinkable water and
DEX
-COOL coolant will:

Give freezing protection down to
-34F (-37C).

Give boiling protection up to 265F (129C).

Protect against rust and corrosion.

Help keep the proper engine temperature.

Let the warning lights and gages work as
they should.
NOTICE:
When adding coolant, it is important that you
use only DEX
-COOL (silicate-free) coolant.
If coolant other than DEX-COOL is added to
the system, premature engine, heater core or
radiator corrosion may result. In addition, the
engine coolant will require change sooner
-- at
30,000 miles (50 000 km) or 24 months,
whichever occurs first. Damage caused by the
use of coolant other than DEX
-COOL is not
covered by your new vehicle warranty.

6-39
Brakes
Brake Fluid
Your brake master cylinder
reservoir is filled with
DOT
-3 brake fluid. See
ªEngine Compartment
Overviewº in the Index for
the location of the reservoir.
There are only two reasons why the brake fluid level in
the reservoir might go down. The first is that the brake
fluid goes down to an acceptable level during normal
brake lining wear. When new linings are put in, the fluid
level goes back up. The other reason is that fluid is
leaking out of the brake system. If it is, you should
have your brake system fixed, since a leak means that
sooner or later your brakes won't work well, or won't
work at all.So, it isn't a good idea to ªtop offº your brake fluid.
Adding brake fluid won't correct a leak. If you add fluid
when your linings are worn, then you'll have too much
fluid when you get new brake linings. You should add
(or remove) brake fluid, as necessary, only when work is
done on the brake hydraulic system.
CAUTION:
If you have too much brake fluid, it can spill on
the engine. The fluid will burn if the engine is hot
enough. You or others could be burned, and your
vehicle could be damaged. Add brake fluid only
when work is done on the brake hydraulic system.
See ªChecking Brake Fluidº in this section.
Refer to the Maintenance Schedule to determine when to
check your brake fluid. See ªPeriodic Maintenance
Inspectionsº in the Index.

6-42
NOTICE:
Continuing to drive with worn-out brake pads
could result in costly brake repair.
Some driving conditions or climates may cause a brake
squeal when the brakes are first applied or lightly
applied. This does not mean something is wrong with
your 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 GM torque specifications.
Brake linings should always be replaced as complete
axle sets.
See ªBrake System Inspectionº in Section 7 of this
manual under Part C ªPeriodic Maintenance Inspections.º
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 of brake trouble.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
Replacing Brake System Parts
The braking system on a vehicle is complex. Its many
parts have to be of top quality and work well together
if the vehicle is to have really good braking. Your
vehicle was designed and tested with top
-quality
GM brake parts. When you replace parts of your braking
system
-- for example, when your brake linings wear
down and you have to have new ones put in
-- be sure
you get new approved GM replacement parts. If you
don't, your brakes may no longer work properly.
For example, if someone puts in brake linings that
are wrong for your vehicle, the balance between your
front and rear brakes can change
-- for the worse.
The braking performance you've come to expect can
change in many other ways if someone puts in the
wrong replacement brake parts.

6-43
Battery
Your new vehicle comes with a maintenance free
ACDelco
battery. When it's time for a new battery,
get one that has the replacement number shown on the
original battery's label. We recommend an ACDelco
battery. See ªEngine Compartment Overviewº in the
Index for battery location.
WARNING: 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
If you're not going to drive your vehicle for 25 days or
more, remove the black, negative (
-) cable from the battery.
This will help keep your battery from running down.
CAUTION:
Batteries have acid that can burn you and gas that
can explode. You can be badly hurt if you aren't
careful. See ªJump Startingº in the Index for tips
on working around a battery without getting hurt.
Contact your dealer to learn how to prepare your vehicle
for longer storage periods.
Also, for your audio system, see ªTheft
-Deterrent
Featureº in the Index.
Bulb Replacement
For any bulb changing procedure not listed in this
section, contact your GM dealership service department.
Before you replace any bulbs, be sure that all the lamps
are off and the engine isn't running. See ªReplacement
Bulbsº in the Index for the proper types of bulbs to use.
Halogen Bulbs
CAUTION:
Halogen bulbs have pressurized gas inside
and can burst if you drop or scratch the bulb.
You or others could be injured. Be sure to read
and follow the instructions on the bulb package.

6-51
Windshield Wiper Blade Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See ªWiper Blade
Checkº in the Index for more information.Replacement blades come in different types and are
removed in different ways. For proper type and length,
see ªNormal Maintenance Replacement Partsº in the
Index. Here's how to remove the Shephard's Hook type.
To replace the windshield wiper blade assembly:
1. Lift the wiper arm and turn the blade until it is facing
away from the windshield.
2. Push the release lever and slide the wiper assembly
toward the driver's side of the vehicle.
3. Install a new blade by reversing Steps 1 and 2.

6-54 Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See ªWhen It's Time for New Tiresº and
ªWheel Replacementº later in this section for more
information. Make sure the spare tire is stored securely.
Push, pull, and then try to rotate or turn the tire.
If it moves, use the wheel wrench/hoist shaft to tighten
the cable. See ªStoring a Flat or Spare Tire and Toolsº
in the Index.
The purpose of regular rotation is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See ªScheduled
Maintenance Servicesº in the Index for scheduled
rotation intervals.
If your vehicle has single rear wheels and the tread
design for your front tires is the same as your rear tires,
always use one of the correct rotation patterns shown
here when rotating your tires.
If your vehicle has front tires with different tread designs
(such as all season vs. on/off road) than the rear tires,
don't rotate your tires front to rear.

6-68
Sheet Metal Damage
If your vehicle is damaged and requires sheet metal
repair or replacement, make sure the body repair shop
applies anti
-corrosion material to the parts repaired or
replaced to restore corrosion protection.
Original manufacturer replacement parts will provide
the corrosion protection while maintaining the warranty.
Finish Damage
Any stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch
-up
materials available from your dealer or other service
outlets. Larger areas of finish damage can be corrected
in your dealer's body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust
control can collect on the underbody. If these are
not removed, accelerated corrosion (rust) can occur
on the underbody parts such as fuel lines, frame,
floor pan and exhaust system even though they have
corrosion protection.At least every spring, flush these materials from the
underbody with plain water. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can
do this for you.
Chemical Paint Spotting
Some weather and atmospheric conditions can create
a chemical fallout. Airborne pollutants can fall upon
and attack painted surfaces on your vehicle. This
damage can take two forms: blotchy, ringlet
-shaped
discolorations, and small irregular dark spots etched
into the paint surface.
Although no defect in the paint job causes this,
GM will repair, at no charge to the owner, the surfaces
of new vehicles damaged by this fallout condition
within 12 months or 12,000 miles (20 000 km) of
purchase, whichever occurs first.
This applies only to materials manufactured and sold by
General Motors. Bodies, body conversions or equipment
not made or sold by General Motors are not covered.