brake BUICK LACROSSE 2007 Workshop Manual

Wait at least 30 minutes before checking the
transaxle uid level if you have been driving:
When outside temperatures are
above 90°F (32°C).
At high speed for quite a while.
In heavy traffic — especially in hot weather.
While pulling a trailer.
To get the right reading, the uid should be
at normal operating temperature, which is
180°F to 200°F (82°C to 93°C).
Get the vehicle warmed up by driving about
15 miles (24 km) when outside temperatures are
above 50°F (10°C). If it is colder than 50°F (10°C),
you may have to drive longer.
Checking the Fluid Level
Prepare the vehicle as follows:
1. Park the vehicle on a level place. Keep the
engine running.
2. With the parking brake applied, place the
shift lever in PARK (P).
3. With your foot on the brake pedal, move the
shift lever through each gear, pausing for
about three seconds in each one. Then,
position the shift lever in PARK (P).
4. Let the engine run at idle for three to
ve minutes.
Then, without shutting off the engine, follow
these steps:
The transaxle uid
dipstick handle has
this symbol on it,
and is located near
the rear of the engine
compartment.
361

Brakes
Brake Fluid
Your brake master
cylinder reservoir is
lled with DOT-3 brake
uid. SeeEngine
Compartment Overview
on page 350for 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 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 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 your brake uid falls to a low level, your
brake warning light will come on. SeeBrake
System Warning Light on page 186.
381

What to Add
When you do need brake uid, use only DOT-3
brake uid. Use new brake uid from a sealed
container only. SeeRecommended Fluids
and Lubricants on page 470.
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 the brake
system, the 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 the 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.
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 442.
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.
382

{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 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.
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.
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.
383

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 following steps 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 would
not be covered by your warranty.
Trying to start your vehicle by pushing or
pulling it will not 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 are
not touching each other. If they are, it could
cause a ground connection you do not want.
You would not 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 before setting the
parking brake.
385

(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/
transaxle, 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.
406

TPMS Sensor Identication Codes
Each TPMS sensor has a unique identication
code. Any time you replace one or more of
the TPMS sensors or rotate the vehicle’s tires, the
identication codes need to be matched to the
new tire/wheel position. The sensors are matched,
to the tire/wheel positions, in the following order:
driver side front tire, passenger side front tire,
passenger side rear tire, and driver side rear tire
using a TPMS diagnostic tool. See your dealer
for service.
The TPMS sensors may also be matched to each
tire/wheel position by increasing or decreasing
the tire’s air pressure. When increasing the tire’s
pressure, do not exceed the maximum ination
pressure indicated on the tire’s sidewall.
You have two minutes to match each tire and
wheel position. If it takes longer than two minutes
to match any tire and wheel position, the
matching process stops and you need to
start over.The TPMS matching process is outlined below:
1. Set the parking brake.
2. Turn the ignition switch to RUN with the
engine off.
3. Press the Remote Keyless Entry (RKE)
transmitter’s LOCK and UNLOCK buttons
at the same time for approximately
ve seconds. The horn sounds twice to
signal the receiver is in relearn mode and the
TPMS sensor matching process can begin.
4. Start with the driver side front tire.
5. Remove the valve cap from the tire’s valve
stem. Activate the TPMS sensor by increasing
or decreasing the tire’s air pressure for
10 seconds, or until a horn chirp sounds.
The horn chirp, which may take up to
30 seconds to sound, conrms that the sensor
identication code has been matched to the
tire/wheel position. To decrease the tire’s
air-pressure use the pointed end of the valve
cap, a pencil-style air pressure gage, or a key.
414

Buying New Tires
GM has developed and matched specic tires
for your vehicle. The original equipment tires
installed on your vehicle, when it was new,
were designed to meet General Motors Tire
Performance Criteria Specication (TPC spec)
system rating. If you need replacement tires,
GM strongly recommends that you get tires with
the same TPC Spec rating. This way, your vehicle
will continue to have tires that are designed to
give the same performance and vehicle safety,
during normal use, as the original tires.GM’s exclusive TPC Spec system considers over
a dozen critical specications that impact the
overall performance of your vehicle, including
brake system performance, ride and handling,
traction control, and tire pressure monitoring
performance. GM’s TPC Spec number is molded
onto the tire’s sidewall by the tire manufacturer.
If the tires have an all-season tread design,
the TPC spec number will be followed by an MS
for mud and snow. SeeTire Sidewall Labeling
on page 403for additional information.
418

Different Size Tires and Wheels
If you add wheels or tires that are a different
size than your original equipment wheels and
tires, this may affect the way your vehicle
performs, including its braking, ride and handling
characteristics, stability, and resistance to
rollover. Additionally, if your vehicle has electronic
systems such as, anti-lock brakes, traction
control, and electronic stability control, the
performance of these systems can be affected.{CAUTION:
If you add different sized wheels, your
vehicle may not provide an acceptable
level of performance and safety if tires
not recommended for those wheels are
selected. You may increase the chance
that you will crash and suffer serious
injury. Only use GM specic wheel and
tire systems developed for your vehicle,
and have them properly installed by a
GM certied technician.
SeeBuying New Tires on page 418and
Accessories and Modications on page 341for
additional information.
420

Each new wheel should have the same
load-carrying capacity, diameter, width, offset
and be mounted the same way as the one
it replaces.
If you need to replace any of your wheels, wheel
bolts, or wheel nuts, replace them only with
new GM original equipment parts. This way,
you will be sure to have the right wheel, wheel
bolts, and wheel nuts for your vehicle.
{CAUTION:
Using the wrong replacement wheels,
wheel bolts, or wheel nuts on your vehicle
can be dangerous. It could affect the
braking and handling of your vehicle,
make your tires lose air and make you
lose control. You could have a collision
in which you or others could be injured.
Always use the correct wheel, wheel
bolts, and wheel nuts for replacement.Notice:The wrong wheel can also cause
problems with bearing life, brake cooling,
speedometer or odometer calibration,
headlamp aim, bumper height, vehicle ground
clearance, and tire or tire chain clearance
to the body and chassis.
SeeChanging a Flat Tire on page 426for more
information.
Used Replacement Wheels
{CAUTION:
Putting a used wheel on your vehicle is
dangerous. You cannot know how it has
been used or how far it has been driven.
It could fail suddenly and cause a crash.
If you have to replace a wheel, use a new
GM original equipment wheel.
423