brake CHEVROLET EXPRESS CARGO VAN 2007 1.G Service Manual

Service
Your dealer knows your vehicle best and wants
you to be happy with it. We hope you will go
to your dealer for all your service needs. You will
get genuine GM parts and GM-trained and
supported service people.
We hope you will want to keep your GM vehicle all
GM. Genuine GM parts have one of these marks:
Accessories and Modications
When you add non-GM accessories 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 anti-lock brakes, traction control and stability
control. Some of these accessories may 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.
290

Checking Things
Under the Hood
{CAUTION:
Things that burn can get on hot engine or
fuel operated heater (FOH) 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 or fuel operated heater (FOH).
Hood Release
To open the hood, do the following:
1. Pull the handle with
this symbol on it.
It is located in front
of the driver’s
side door frame
near the floor.
300

A. Battery. SeeBattery on page 329.
B. Radiator Pressure Cap. SeeRadiator Pressure
Cap on page 315.
C. Coolant Recovery Tank. SeeCooling System
on page 317.
D. Automatic Transmission Fluid Dipstick. See
“Checking the Fluid Level” underAutomatic
Transmission Fluid on page 309.
E. Engine Oil Fill Cap. See “When to Add Engine
Oil” underEngine Oil (Gasoline Engine) on
page 303.
F. Engine Oil Dipstick. See “Checking Engine Oil”
underEngine Oil (Gasoline Engine) on
page 303.
G. Engine Air Cleaner/Filter. SeeEngine
Air Cleaner/Filter on page 308.
H. Power Steering Fluid Reservoir. SeePower
Steering Fluid on page 323.
I. Brake Master Cylinder Reservoir. See “Brake
Fluid” underBrakes on page 325.
J. Windshield Washer Fluid Reservoir. See
“Adding Washer Fluid” underWindshield
Washer Fluid on page 324.Engine Oil (Gasoline Engine)
If your vehicle has a diesel engine, see “Engine
Oil” in the DURAMAX®Diesel Engine Supplement.
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.
SeeEngine Compartment Overview on page 302
for 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.
303

Checking the Fluid Level
Prepare your vehicle as follows:
1. Park your 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 range, pausing
for about three seconds in each range.
Then, position the shift lever in PARK (P).
4. Let the engine run at idle for three minutes
or more.
Then, without shutting off the engine, follow
these steps:
The transmission
dipstick is located near
the center of the
engine compartment
and will be labeled with
the graphic shown.SeeEngine Compartment Overview on page 302
for more information on location.
1. Flip the handle up and then 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.
3. Check both sides of the dipstick, and read the
lower level. The fluid level must be in the
COLD area for a cold check or in the HOT
or cross-hatched area for a hot check. Be sure
to keep the dipstick pointed down to get an
accurate reading.
4. If the fluid level is in the acceptable range,
push the dipstick back in all the way; then
flip the handle down to lock the dipstick
in place.
311

How to Check Power Steering Fluid
To check the power steering fluid, do the following:
1. Turn the key off and let the engine
compartment cool down.
2. Wipe the cap and the top of the
reservoir clean.
3. Unscrew the cap and wipe the dipstick
with a clean rag.
4. Replace the cap and completely tighten it.
5. Then remove the cap again and look at
the fluid level on the dipstick.
The level should be at the COLD FILL mark.
If necessary, add only enough fluid to bring
the level up to the mark.
To prevent contamination of brake fluid, never
check or fill the power steering reservoir with
the brake master cylinder cover off.
What to Use
To determine what kind of fluid to use, see
Recommended Fluids and Lubricants on page 415.
Always use the proper fluid. Failure to use the
proper fluid can cause leaks and damage hoses
and seals.
Windshield Washer Fluid
What to Use
When you need windshield washer fluid, be sure
to read the manufacturer’s instructions before
use. If you will be operating your vehicle in an area
where the temperature may fall below freezing,
use a fluid that has sufficient protection against
freezing.
Adding Washer Fluid
Open the cap with the
washer symbol on it.
Add washer fluid
until the tank is full. See
Engine Compartment
Overview on page 302
for reservoir location.
324

Notice:
When using concentrated washer uid,
follow the manufacturer’s instructions
for adding water.
Do not 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 does not clean as well
as washer uid.
Fill the washer uid tank only
three-quarters full when it is very cold.
This allows for uid expansion if freezing
occurs, which could damage the tank if
it is completely full.
Do not use engine coolant (antifreeze) in
your windshield washer. It can damage
the vehicle’s windshield washer system
and paint.
Brakes
Brake Fluid
The brake master
cylinder reservoir is
filled with DOT-3 brake
fluid. SeeEngine
Compartment Overview
on page 302for 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 the
brake system fixed, since a leak means that
sooner or later the brakes will not work well.
So, it is not a good idea to top off the brake fluid.
Adding brake fluid will not correct a leak.
325

If you add fluid when the linings are worn, then
you will 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 uid, it can
spill on the engine and/or fuel operated
heater parts, if equipped. If your vehicle
has a diesel engine and a fuel operated
heater, see “Fuel Operated Heater (FOH)”
in the diesel engine supplement. 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. See “Checking Brake
Fluid” in this section.
Refer to the Maintenance Schedule to determine
when to check the brake fluid. SeeScheduled
Maintenance (Gasoline Engine) on page 405.
Checking Brake Fluid
You can check the brake fluid without taking
off the cap.
Look at the brake fluid
reservoir. The fluid level
should be above MIN.
If it is not, have the brake
system checked to see
if there is a leak.
After work is done on the brake hydraulic system,
make sure the level is above the MIN but not
over the MAX mark.
326

What to Add
When you do need brake fluid, use only DOT-3
brake fluid. Use new brake fluid from a sealed
container only. SeeRecommended Fluids
and Lubricants on page 415.
Always clean the brake fluid 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.
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 386.
327

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 can 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 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 first 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
specifications inCapacities and Specications
on page 398.
Brake linings should always be replaced as
complete axle sets.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 make a brake stop, the disc
brakes adjust for wear.
328

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.
Battery
Your vehicle has a maintenance free 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
®
replacement battery. SeeEngine Compartment
Overview on page 302for 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.
329