1998 CHEVROLET EXPRESS service

Downloaded from www.Manualslib.com manuals search engine 5. Install a new filter element with the folds in the
down position.
Reverse Steps 1 through
4 to replace the air cleaner.
See “Normal Replacement Parts” for the proper filter
to use.
Refer to the Maintenance Schedule
to determine when to
replace the air filter and crankcase ventilation filter.
See “Scheduled Maintenance Services” in the Index.
I /!1 CAUTION:
Operating the engine with the air cleaner off can
cause
you or others to be burned. The air cleaner
not only cleans the air, it stops flame
if the engine
backfires.
If it isn’t there, and the engine
backfires, you could be burned. Don’t drive with
it
off, and be careful working on the engine with
the air cleaner
off.
I NOTICE: I
If the air cleaner is off, a backfire can cause a
damaging engine fire. And, dirt can easily get
into your engine, which will damage it. Always
have the air cleaner in place when you’re driving.
Automatic Transmission Fluid
If your vehicle has a diesel engine, see “Automatic
Transmission Fluid” in the Diesel Supplement.
When to Check and Change
A good time to check your automatic transmission fluid
level is when the engine oil
is changed.
Change both the fluid and filter every
50,000 miles
(83 000 km) if the vehicle’s GVWR is over 8,600 or
if the vehicle
is mainly driven under one or more of
these conditions:
In heavy city traffic where the outside temperature
regularly reaches
90” F (32” C) or higher.
In hilly or mountainous terrain.
0 When doing frequent trailer towing.
6-17

Downloaded from www.Manualslib.com manuals search engine Uses such as found in taxi, police or delivery service.
If your vehicle’s GVWR is not over
8,600 and you
do not use your vehicle under any of these conditions,
change the fluid and filter every 100,000 miles
(166 000 km).
See “Scheduled Maintenance Services”
in the Index.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at your GM dealership
Service Department.
If you do it yourself, be sure to follow all the
instructions here, or you could get a false reading
on the dipstick.
NOTICE:
Too much or too little fluid can damage your
transmission.
Too much can mean that some of
the fluid could come out and fall on hot engine
parts
or exhaust system parts, starting a fire. Be
sure to get an accurate reading if you check your
transmission fluid.
Wait at least 30 minutes before checking the
transmission fluid level
if you have been driving:
0 When outside temperatures are above 90°F (32°C).
0 At high speed for quite a while.
In heavy traffic -- especially in hot weather.
0 While pulling a trailer.
To get the right reading, the fluid should be at normal
operating temperature, which is
180°F to 200°F
(82°C to 93 “C). See “Checking Transmission Fluid
Hot” in the Index.
Checking Transmission Fluid Hot
Get the vehicle warmed up by driving about 15 miles
(24 km) when outside temperatures are above
50°F
(10°C). If it’s colder than 50°F (lO”C), drive the
vehicle in
in DRIVE (D) until the engine temperature
gage moves and then remains steady for 10 minutes.
Then follow the hot check procedures.

Downloaded from www.Manualslib.com manuals search engine Rear Axle What to Use
When to Check and Change Lubricant
Refer to the Maintenance Schedule to determine how
often
to check the lubricant and when to change it. See
“Scheduled Maintenance Services” in the Index.
How to Check Lubricant
If the level is below the
bottom
of the filler plug
hole, you’ll need to add
some lubricant. Add enough
lubricant to raise the level
to the bottom of the filler
plug hole. Refer
to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants” in the Index.
Engine Coolant
The cooling s stem in your vehicle is filled with
DEX-COOL engine coolant. This coolant is designed
to remain in your vehicle for
5 years or 150,000 miles
(240
000 kmg whichever occurs first, if you add only
DEX-COOL extended life coolant.
8
The following explains your cooling system and how to
add coolant when it is low. If you have a problem with
engine overheating, see “Engine Overheating” in the
Index.
A 50/50 mixture of water and DEX-COOL@
coolant will:
0 Give freezing protection down to -34°F (-37°C).
Give boiling protection up to 265 “F (1 29” C).
Protect against rust and corrosion.
0 Help keep the proper engine temperature.
0 Let the warning lights and gages work as
they should.

Downloaded from www.Manualslib.com manuals search engine Brake Wear
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).
r
I
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.
I 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 torque wheel nuts in
the proper sequence
to GM specifications.
Your rear drum brakes 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 “Brake System Inspection’’ in Section
7 of this
manual under Part
C “Periodic Maintenance Inspections.’’
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.

Downloaded from www.Manualslib.com manuals search engine 2.
3.
4.
5.
6.
7.
Press down on the blade assembly pivot locking tab.
Pull down on the blade assembly to release it from
the wiper arm hook.
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.
To install the new wiper insert, slide the notched
end last, into the end with two blade claws. Slide
the insert all the way through the blade claws at the
opposite end.
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 slot.
Put the blade assembly pivot in the wiper arm
hook. Pull up until the pivot locking tab locks in
the hook slot.
Carefully lower the wiper
arm and blade assembly
into the windshield.
Tires
Yo%fS%%v vehicle comes with high-quality tires made by
a leading tire manufacturer. If you ever have questions
about your tire warranty and where to
obtain service, see
your
GM Warranty booklet for details.
A CAUTIOI.:
Poorly maintained and improperly used tires
are dangerous.
0
0
0
0
Overloading your tires can cause
overheating as
a result of too much friction.
You could have an air-out and a serious
accident. See “Loading Your Vehicle” in
the Index.
Underinflated tires pose the same danger
as overloaded tires. The resulting accident
could cause serious injury. Check all tires
frequently to maintain the recommended
pressure. Tire pressure should be checked
when your tires are cold.
Overinflated tires are more likely
to be
cut, punctured
or broken by a sudden
impact
-- such as when you hit a pothole.
Keep tires at the recommended pressure.
Worn, old tires can cause accidents.
If your
tread is badly worn, or if your tires have
been damaged, replace them.
6-41

Downloaded from www.Manualslib.com manuals search engine How to Check
Use a good quality pocket-type gage to check tire
pressure. You can’t tell if your tires are properly inflated
simply by looking at them. Radial tires may look
properly inflated even when they’re underinflated.
Be sure to put the valve caps back on the valve
stems. They help prevent leaks by keeping out dirt
and moisture.
Tire Inspection and Rotation
Tires should be rotated every 6,000 to 8,000 miles
(10 000 to 13 000 km). Any time you notice unusual
wear, rotate your tires as soon as possible and check
wheel alignment. Also check for damaged tires or
wheels. See “When It’s Time for New Tires” and
“Wheel Replacement” later
in this section for more
information.
If your vehicle has dual rear wheels,
also see “Dual Tire Operation” later in this section. The
purpose of regular rotation
is to achieve more
uniform wear for all tires on the vehicle. The first
rotation is the most important. See “Scheduled
Maintenance Services”
in the Index for scheduled
rotation intervals.
If your vehicle has single rear wheels, always use one of
the correct rotation patterns shown here when rotating
your tires.
6-43
~.

Downloaded from www.Manualslib.com manuals search engine I A CAUTION:
If you operate your vehicle with a tire that is
badly underinflated, the tire can overheat.
An
overheated tire can lose air suddenly or catch
fire. You or others could be injured. Be sure all
tires (including the spare) are properly inflated.
Buying New Tires
To find out what kind and size of tires you need, look at
the CertificatiodTire label.
The tires installed
on your vehicle when it was new had
a Tire Performance Criteria Specification (TPC Spec)
number on each tire’s sidewall. When you get new tires,
get ones with that same TPC Spec number. That way
your vehicle will continue
to have tires that are designed
to give proper endurance, handling, speed rating,
traction, ride and other things during normal service
on your vehicle. If your tires have an all-season tread
design, the TPC number will be followed by an
“MS”
(for mud and snow). If you
ever replace your tires with those
not having a
TPC Spec number, make sure they are the same size,
load range, speed rating and construction type (bias,
bias-belted or radial) as your original tires.
Mixing tires could cause you to lose control while
driving.
If you mix tires of different sizes or types
(radial and bias-belted tires), the vehicle may not
handle properly, and you could have a crash.
Using tires
of different sizes may also cause
damage
to your vehicle. Be sure to use the same
size and type tires on all wheels.

Downloaded from www.Manualslib.com manuals search engine TIION:
If you use bias-ply tires on your vehicle, the
wheel rim flanges could develop cracks after
many miles of driving.
A tire and/or wheel could
fail suddenly, causing a crash. Use only radial-ply
tires with the wheels on your vehicle.
Uniform Tire Quality Grading
The following information relates to the system
developed by the United States National Highway
Traffic Safety Administration, which grades tires by
treadwear, traction and temperature performance.
(This applies only to vehicles sold in the United
States.) The grades are molded on the sidewalls of
most passenger car tires. The Uniform Tire Quality
Grading system does not apply
to deep tread,
winter-type snow tires, space-saver or temporary
use spare tires, tires with nominal rim diameters
of
10 to 12 inches (25 to 30 cm), or to some
limited-production tires. While
the tires available on General Motors passenger
cars and light trucks may vary with respect to these
grades, they must also conform
to Federal safety
requirements and additional General Motors Tire
Performance Criteria (TPC) standards.
Treadwear
The treadwear grade is a comparative rating based on
the wear rate
of the tire when tested under controlled
conditions
on a specified government test course. For
example, a
tire graded 150 would wear one and a
half
(1 1/2) times as well on the government course
as
a tire graded 100. The relative performance of tires
depends upon
the actual conditions of their use,
however, and may depart significantly from the norm
due to variations in driving habits, service practices
and differences in road characteristics and climate.