brake BUICK LESABRE 2004 Service Manual

Checking Things Under
the Hood
{CAUTION:
An electric fan under the hood can start up
and injure you even when the engine is not
running. Keep hands, clothing and tools away
from any underhood electric fan.
{CAUTION:
Things that burn can get on hot engine parts
and start a re. These include liquids like fuel,
oil, coolant, brake uid, windshield washer and
other uids, and plastic or rubber. You or
others could be burned. Be careful not to drop
or spill things that will burn onto a hot engine.
5-10

Hood Release
To open the hood, do the following:
1. Pull the hood release
handle inside the
vehicle. It is located
next to the parking
brake pedal near
the oor.
2. Then go to the front of the vehicle and pull up on
the secondary hood release. The hood latch is
located under the hood, near the center, and at the
front edge of the grille.
3. Lift up on the latch as you lift up on the hood.
Before closing the hood, be sure all the ller
caps are on properly. Then just pull the hood down
and close it rmly.
5-11

A. Engine Compartment Fuse Block. See “Engine
Compartment Fuse Block” underFuses and Circuit
Breakers on page 5-92.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-36.
C. Remote Positive (+) Terminal. SeeJump Starting on
page 5-42.
D. Engine Coolant Recovery Tank. SeeCooling System
on page 5-28.
E. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-26.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-13.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-13.
H. Engine Coolant Air Bleed Valve. See “How to Add
Coolant to the Radiator” underCooling System
on page 5-28.
I. Automatic Transaxle Fluid Dipstick. See “Checking
the Fluid Level” underAutomatic Transaxle Fluid
on page 5-21.
J. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-37.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-18.Engine Oil
If the ENGINE OIL LOW
CHECK LEVEL DIC
message appears on the
instrument cluster, it
means you need to check
your engine oil level
right away. For more
information, seeDIC
Warnings and Messages
on page 3-49.
You should check your engine oil level regularly; this is
an added reminder.
Checking Engine Oil
It is a good idea to check your engine oil every time you
get fuel. In order to get an accurate reading, the oil
must be warm and the vehicle must be on level ground.
The engine oil dipstick handle is a yellow loop. See
Engine Compartment Overview on page 5-12for
the location of the engine oil dipstick.
Turn off the engine and give the oil several minutes to
drain back into the oil pan. If you do not, the oil dipstick
might not show the actual level.
5-13

Checking the Fluid Level
Prepare your vehicle as follows:
Park your vehicle on a level place. Keep the engine
running.
With the parking brake applied, place the shift lever
in PARK (P).
With your foot on the brake pedal, move the shift
lever through each gear range, pausing for about
three seconds in each range. Then, position the shift
lever in PARK (P).
Let the engine run at idle for three to ve minutes.Then, without shutting off the engine, follow these steps:
The transaxle uid dipstick
top is a round, red loop
and is located next to the
brake master cylinder
behind the engine block.
SeeEngine Compartment
Overview on page 5-12
for more information
on location.
1. Pull out the dipstick and wipe it with a clean rag or
paper towel.
2. Push it back in all the way, wait three seconds and
then pull it back out again.
5-22

Notice:
When using concentrated washer uid, follow
the manufacturer’s instructions for adding
water.
Don’t mix water with ready-to-use washer uid.
Water can cause the solution to freeze and
damage your washer uid tank and other parts
of the washer system. Also, water doesn’t
clean as well as washer uid.
Fill your washer uid tank only three-quarters
full when it’s very cold. This allows for
expansion if freezing occurs, which could
damage the tank if it is completely full.
Don’t use engine coolant (antifreeze) in your
windshield washer. It can damage your
washer system and paint.
Brakes
Brake Fluid
Your master cylinder reservoir is lled with DOT-3 brake
uid. SeeEngine Compartment Overview on page 5-12
for the location of the reservoir.
There are only two reasons why the brake uid level in
the reservoir might go down. The rst is that the
brake uid goes down to an acceptable level during
normal brake lining wear. When new linings are put in,
the uid level goes back up.
5-37

The other reason is that uid is leaking out of the brake
system. If it is, you should have your brake system
xed, since a leak means that sooner or later your
brakes will not work well, or will not work at all.
So, it is not a good idea to “top off” your brake uid.
Adding brake uid will not correct a leak. If you add uid
when your linings are worn, then you will have too
much uid when you get new brake linings. You should
add (or remove) brake uid, as necessary, only when
work is done on the brake hydraulic system.
{CAUTION:
If you have too much brake uid, it can spill on
the engine. The uid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
uid only when work is done on the brake
hydraulic system.
When your brake uid falls to a low level, your brake
warning light will come on. A chime will sound if you try
to drive with this warning light on. SeeBrake System
Warning Light on page 3-37.
What to Add
When you do need brake uid, use only DOT-3 brake
uid. Refer toPart D: Recommended Fluids and
Lubricants on page 6-23. Use new brake uid from a
sealed container only.
Always clean the brake uid reservoir cap and the area
around the cap before removing it. This will help
keep dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in your brake
system, your brakes may not work well, or
they may not even work at all. This could
cause a crash. Always use the proper brake
uid.
Notice:
Using the wrong uid can badly damage brake
system parts. For example, just a few drops of
mineral-based oil, such as engine oil, in your
brake system can damage brake system parts so
badly that they will have to be replaced. Do not
let someone put in the wrong kind of uid.
5-38

If you spill brake uid on your vehicle’s painted
surfaces, the paint nish can be damaged. Be
careful not to spill brake uid on your vehicle. If
you do, wash it off immediately. SeeAppearance
Care on page 5-83.
Brake Wear
Your vehicle has four-wheel disc 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 rmly).
{CAUTION:
The brake wear warning sound means that
soon your brakes will not 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 rst 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 specications.
Brake linings should always be replaced as complete
axle sets.
SeeBrake System Inspection on page 6-22.
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 apply the brakes, with or without the
vehicle moving, your brakes adjust for wear.
5-39

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 need new ones put in — be sure
you get new approved GM replacement parts. If you do
not, 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 have 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 is time for a new battery, get
one that has the replacement number shown on the
original battery’s label. We recommend an
ACDelco
®battery.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.
The battery is located under the rear seat cushion. To
access the battery, seeRemoving the Rear Seat
Cushion on page 5-95. You do not need to access the
battery to jump start your vehicle. SeeJump Starting
on page 5-42.
{CAUTION:
A battery that is not properly vented can let
sulfuric acid fumes into the area under the rear
seat cushion. These fumes can damage your
rear seat safety belt systems. You may not be
able to see this damage, and the safety belts
might not provide the protection needed in a
crash. If a replacement battery is ever needed,
it must be vented in the same manner as the
original battery. Always make sure that the
vent hose is properly reattached before
reinstalling the seat cushion.
5-40

Jump Starting
If your vehicle’s battery has run down, you may want to
use another vehicle and some jumper cables to start
your vehicle. Be sure to use the steps below to do
it safely.
{CAUTION:
Batteries can hurt you. They can be dangerous
because:
They contain acid that can burn you.
They contain gas that can explode or
ignite.
They contain enough electricity to
burn you.
If you do not follow these steps exactly, some
or all of these things can hurt you.Notice:Ignoring these steps could result in costly
damage to your vehicle that wouldn’t be covered
by your warranty.
Trying to start your vehicle by pushing or pulling it
won’t work, and it could damage your vehicle.
1. Check the other vehicle. It must have a 12-volt
battery with a negative ground system.
Notice:If the other vehicle’s system is not a 12-volt
system with a negative ground, both vehicles can
be damaged. Only use vehicles with 12-volt systems
with negative grounds to jump start your vehicle.
2. Get the vehicles close enough so the jumper cables
can reach, but be sure the vehicles aren’t touching
each other. If they are, it could cause a ground
connection you don’t want. You wouldn’t be able to
start your vehicle, and the bad grounding could
damage the electrical systems.
To avoid the possibility of the vehicles rolling, set
the parking brake rmly on both vehicles involved in
the jump start procedure. Put an automatic
transaxle in PARK (P) or a manual transaxle in
NEUTRAL (N) before setting the parking brake.
5-42

Tire Size
The following illustration shows an example of a typical
passenger car tire size.
(A) P-Metric Tire:The United States version of a
metric tire sizing system. The letter “P” as the
rst character in the tire size means a passenger
vehicle tire engineered to standards set by the U. S.
Tire and Rim Association.
(B) Tire Width:The three-digit number indicates the
tire section width in millimeters from sidewall to sidewall.
(C) Aspect Ratio:A two-digit number that indicates
the tire height-to-width measurements. For example, if
the tire size aspect ratio is “70,” as shown in item “C” of
the illustration, it would mean that the tire’s sidewall is
70% as high as it is wide.(D) Construction Code:A letter code is used to
indicate the type of ply construction in the tire. The letter
“R” means radial ply construction; the letter “D” means
diagonal or bias ply construction; and the letter “B”
means belted-bias ply construction.
(E) Rim Diameter:Diameter of the wheel in inches.
(F) Service Description:These characters represent
the load range and the speed rating of a tire. The
load range represents the load carrying capacity a tire is
certied to carry. The load index can range from 1 to
279. The speed rating is the maximum speed a tire
is certied to carry a load. Speed ratings range from
“A” to “Z”.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the tire pressing
outward on each square inch of the tire. Air pressure
is expressed in pounds per square inch (psi) or
kilopascal (kPa).
Accessory Weight:This means the combined weight
of optional accessories. Some examples of optional
accessories are, automatic transmission, power steering,
power brakes, power windows, power seats, and air
conditioning.
Aspect Ratio:The relationship of a tire’s height to its
width.
5-62