GMC SONOMA 2001 Owner's Manual

6-36 Brake Wear
If you have four-wheel drive, your vehicle has
four
-wheel disc brakes. If not, your vehicle has front
disc brakes and rear drum 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 may come and go or
be heard all the time your vehicle is moving (except when
you are pushing on the brake pedal firmly).
CAUTION:
The brake wear warning sound means that soon
your brakes won't work well. That could lead to
an accident. When you hear the brake wear
warning sound, have your vehicle serviced.
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.
If you have rear drum brakes, they don't have wear
indicators, but if you ever hear a rear brake rubbing
noise, have the rear brake linings inspected immediately.
Also, the rear brake drums should be removed and
inspected each time the tires are removed for rotation or
changing. When you have the front brake pads replaced,
have the rear brakes inspected, too.
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.

6-37 Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
If you don't have four
-wheel drive and your brake pedal
goes down farther than normal, your rear drum brakes
may need adjustment. Adjust them by backing up and
firmly applying the brakes a few times.
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.
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.

6-38 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
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 any bulb changing procedure not listed in this
section, contact your GM dealer's service department.
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.

6-39 Headlamps
One-Piece Composite Headlamp System
1. Open the hood.
2. Remove the black retainer clips by lifting up.
3. Pull the headlamp assembly out.
4. Unplug the electrical connector.
5. Turn the bulb assembly counterclockwise to remove
it from the headlamp assembly.
6. Put the new bulb into the bulb assembly and reinstall
it in the headlamp assembly by turning it clockwise
until it is tight.
7. Plug in the electrical connector.
8. Put the headlamp assembly back into the vehicle.
Install the two retaining clips.

6-40
Tw o-Piece Composite Headlamp System
1. Open the hood.
2. Remove the black retainer clips by lifting up.
3. Unplug the electrical connector
4. Pull the headlamp lens assembly out.
5. Turn the bulb assembly counterclockwise to remove
it from the headlamp assembly.
6. Put the new bulb into the bulb assembly and reinstall
it in the headlamp assembly by turning it clockwise
until it is tight.
7. Plug in the electrical connector.
8. Put the headlamp lens assembly back into the
vehicle. Install the two retaining clips.

6-41 One-Piece Front Turn Signal
Lamp Assembly
1. Remove the headlamp assembly as shown under
ªOne
-Piece Composite Headlamp Systemº earlier
in this section.
2. Twist the bulb socket
counterclockwise to
remove it from the
headlamp assembly.
3. Pull the bulb straight out to remove it from
the socket.
4. Push the new bulb into the socket until it snaps
into place.
5. Put the bulb socket into the lamp assembly and twist
it clockwise until it is tight.
6. Put the headlamp assembly back into the vehicle.
Install the two retaining clips.
Two-Piece Front Turn Signal
Lamp Assembly
1. Remove the headlamp assembly as shown under
ªTwo
-Piece Composite Headlamp Systemº earlier
in this section.
2. Locate the locking tabs
on the assembly.
Squeeze the tabs
together and push that
end of the assembly out
while holding the tabs.
The assembly will
swing out.
3. Unplug the electrical connector.

6-42
4. Turn the harness bulb socket counterclockwise to
remove it. Pull the bulb straight out to remove it
from the socket.
5. Push the new bulb into the socket until it snaps
into place.
6. Put the socket into the lamp assembly and turn it
clockwise until it is tight.
7. To reinstall the assembly, snap the outboard end of
the lamp assembly back into the vehicle. Then swing
the assembly in and snap it into place.
8. Install the two retaining clips.
Center High-Mounted Stoplamp
1. Remove the lens retaining screws.
2. Remove the lens.

6-43
3. Remove the bulb.
4. Install a new bulb.
5. Reinstall the lens and tighten the screws.
If equipment such as a cap or camper is installed on
your vehicle, a center high
-mounted stoplamp feed wire
is provided along the driver's side rear frame. This wire
should be used to install a center high
-mounted
stoplamp in the cap or camper.
Taillamps
1. Open the tailgate.
2. Remove the screws from
the lamp assembly near
the tailgate latch.
3. Pull the assembly away from the pickup side panel.
4. Turn the socket counterclockwise to remove it.
Push the tab in while you turn the socket.
5. Pull the bulb out.
6. Push the new bulb into the socket.
7. Put the socket into the assembly and turn the socket
clockwise until it locks in place.
8. Reinstall the assembly. Install and tighten the screws.
9. Close the tailgate.

6-44
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.
NOTICE:
Use care when removing or installing a blade
assembly. Accidental bumping can cause the
arm to fall back and strike the windshield.
1. To remove the old wiper blades, lift the wiper arm
until it locks into a vertical position.
A. Blade Assembly
B. Arm Assembly
C. Locking TabD. Blade Pivot
E. Hook Slot
F. Arm Hook
2. Press down on the blade assembly pivot locking tab.
Pull down on the blade assembly to release it from
the wiper arm hook.
3. Remove the insert from the blade assembly. The
insert has two notches at one end that are locked by
bottom claws of the blade assembly. At the notched
end, pull the insert from the blade assembly.

6-45
4. To install the new wiper insert, slide the insert (D),
notched end last, into the end with two blade
claws (A). Slide the insert all the way through the
blade claws at the opposite end (B). The plastic
caps (C) will be forced off as the insert is
fully inserted.
5. Be sure that the notches are locked by the bottom
claws. Make sure that all other claws are properly
locked on both sides of the insert slots.
A. Claw in Notch
B. Correct Installation
C. Incorrect Installation
6. Put the blade assembly pivot in the wiper arm hook.
Pull up until the pivot locking tab locks in the
hook slot.
7. Carefully lower the wiper arm and blade assembly
onto the windshield.