2008 BUICK LUCERNE brakes

Service
For service and parts needs, visit your dealer/retailer.
You will receive genuine GM parts and GM-trained and
supported service people.
Genuine GM parts have one of these marks:
Accessories and Modications
When non-dealer/non-retailer accessories are added to
your vehicle they can affect your vehicle’s performance
and safety, including such things as, airbags, braking,
stability, ride and handling, emissions systems,
aerodynamics, durability, and electronic systems like
antilock brakes, traction control and stability control.
Some of these accessories could even cause
malfunction or damage not covered by warranty.
GM Accessories are designed to complement and
function with other systems on your vehicle. Your GM
dealer/retailer can accessorize your vehicle using
genuine GM Accessories. When you go to your GM
dealer/retailer and ask for GM Accessories, you
will know that GM-trained and supported service
technicians will perform the work using genuine GM
Accessories.
Also, seeAdding Equipment to Your Airbag-Equipped
Vehicle on page 1-72.
5-3

A. Radiator Pressure Cap. SeeRadiator Pressure Cap
on page 5-28.
B. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-41.
C. Remote Positive (+) Battery Terminal. SeeJump
Starting on page 5-48.
D. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-106.
E. Engine Coolant Recovery Tank. See Index.
F. Power Steering Fluid Reservoir (Out of View). See
Power Steering Fluid on page 5-40.
G. Electric Engine Cooling Fans. See Index.H. Engine Oil Dipstick (Out of View). See “Checking
Engine Oil” underEngine Oil on page 5-15.
I. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
J. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 5-21.
K. Brake Fluid Reservoir. See “Brake Fluid” under
Brakes on page 5-42.
L. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-20.
5-13

A. Underhood Fuse Block. SeeUnderhood Fuse Block
on page 5-106.
B. Remote Positive (+) Terminal. SeeJump Starting on
page 5-48.
C. Windshield Washer Fluid Reservoir. See “Adding
Washer Fluid” underWindshield Washer Fluid
on page 5-41.
D. Engine Coolant Surge Tank and Pressure Cap See
Coolant Surge Tank Pressure Cap on page 5-28
andCooling System (3.8L V6 Engine) on page 5-30
orCooling System (4.6L V8 Engine) on page 5-36.
E. Remote Negative (−) Terminal. SeeJump Starting on
page 5-48.
F. Power Steering Fluid. SeePower Steering Fluid on
page 5-40.
G. Engine Oil Fill Cap. See “When to Add Engine Oil”
underEngine Oil on page 5-15.
H. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil on page 5-15.
I. Brake Master Cylinder Reservoir. See “Brake Fluid”
underBrakes on page 5-42.
J. Automatic Transmission Fluid Cap and Dipstick (Out
of View). SeeAutomatic Transmission Fluid on
page 5-21.
K. Engine Air Cleaner/Filter. SeeEngine Air
Cleaner/Filter on page 5-20.Engine Oil
Checking Engine Oil
It is a good idea to check the 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.
1. Turn off the engine and give the oil several minutes
to drain back into the oil pan. If you do not do this,
the oil dipstick might not show the actual level.
2. Pull out the dipstick and clean it with a paper towel
or cloth, then push it back in all the way. Remove it
again, keeping the tip down, and check the level.
5-15

Brakes
Brake Fluid
The brake master cylinder
reservoir is lled with
DOT-3 brake uid. See
Engine Compartment
Overview on page 5-12for
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. The other reason is
that uid is leaking out of the brake hydraulic system. If
it is, you should have the brake hydraulic system
xed, since a leak means that sooner or later the brakes
will not work well.It is not a good idea to top off the brake uid. Adding
brake uid will not correct a leak. If uid is added when
the linings are worn, there will be too much uid
when new brake linings are installed. Add or remove
brake uid, as necessary, only when work is done on the
brake hydraulic system.
{CAUTION:
If your vehicle has 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 the brake uid falls to a low level, the brake
warning light comes on. SeeBrake System Warning
Light on page 3-39.
5-42

What to Add
When you need brake uid, use only DOT-3 brake uid.
Use new brake uid from a sealed container only.
SeeRecommended Fluids and Lubricants on page 6-12.
Always clean the brake uid reservoir cap and the
area around the cap before removing it. This helps keep
dirt from entering the reservoir.
{CAUTION:
With the wrong kind of uid in the brake
hydraulic system, the brakes might not work
well. This could cause a crash. Always use the
proper brake uid.Notice:
Using the wrong uid 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 uid.
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. SeeWashing
Your Vehicle on page 5-98.
5-43

Brake Wear
Your vehicle has 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 can 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 the 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 can cause a brake
squeal when the brakes are rst applied or lightly
applied. This does not mean something is wrong with
the 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 torque specications in
Capacities and Specifications on page 5-113.
Brake linings should always be replaced as complete
axle sets.
5-44

Brake Pedal Travel
See your dealer/retailer 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 that brake service
might be required.
Brake Adjustment
Every time you apply the brakes, with or without the
vehicle moving, the 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 brake parts.
When you replace parts of the braking system — for
example, when the brake linings wear down and you
need new ones put in — be sure you get new approved
replacement parts. If you do not, the brakes might not
work properly. For example, if someone puts in brake
linings that are wrong for your vehicle, the balance
between the 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.
5-45

(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is
60, as shown in item C of the illustration, it would
mean that the tire’s sidewall is 60 percent 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 speed rating of the
tire. The load index represents the load carry
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.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
5-64