1998 GMC SIERRA service

NOTICE:
0
0
Using the wrong fluid 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’ll have to be
replaced. Don’t let someone put in the
wrong kind of fluid.
If you spill brake fluid on your vehicle’s
painted surfaces, the paint finish can be
damaged.
Be careful not to spill brake fluid
on your vehicle. If you do, wash it
off
immediately. See “Appearance Care” in
the Index.
Brake Wear
If you have a C 3500 HD model, it has four-wheel disc
brakes without wear indicators. If you ever hear
a brake
rubbing noise, have the brake linings inspected.
If your pickup is not a
C 3500 HD model, it has front
disc brakes and rear drum brakes. Disc brake pads
(except
C 3500 HD models) 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).
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.
6-37
ProCarManuals.com

Tires
Your new 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 CAUTION:
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.
6-51
ProCarManuals.com

When to Check
Check your tires once a month or more. Also, check the
tire pressure of the spare tire.
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.
1
FRT FRT
[x[
If your vehicle has single rear wheels, always use one of
the correct rotation patterns shown here when rotating
your tires.
If your vehicle has front tires with different load ranges
or tread designs (such as all season vs. on/off road) than
the rear tires, don’t rotate your tires front
to rear.
6-53
ProCarManuals.com

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.
I A CAUTION:
If you use biasuply 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
I 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 I2 inches (25 to 30 cm),
or to some limited-production tires.
6-57
ProCarManuals.com

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.
Traction -- A, B, C
The traction grades, from highest to lowest, are A, B, and
C, and they represent the tire’s ability to stop
on wet
pavement
as measured under controlled conditions on
specified government test surfaces of asphalt and concrete.
A tire marked C may have poor traction performance. Warning:
The traction grade assigned to this tire is based
on braking (straight ahead) traction tests and does not
include cornering (turning) traction.
Temperature -- A, B, C
The temperature grades are A (the highest), B, and C,
representing the tire’s resistance to the generation of
heat and its ability
to dissipate heat when tested under
controlled conditions
on a specified indoor laboratory
test wheel. Sustained high temperature can cause the
material of
the tire to degenerate and reduce tire life, and
excessive temperature can lead to sudden tire failure.
The grade
C corresponds to a level of performance
which
all passenger car tires must meet under the
Federal Motor Vehicle Safety Standard
No. 109.
Grades B and A represent higher levels of performance
on the laboratory test wheel than the minimum required
by law.
Warning: The temperature grade for this tire is
established for a tire that is properly inflated and
not
overloaded. Excessive speed, underinflation, or
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.
6-58
ProCarManuals.com

Finish Damage Chemical Paint Spotting
Any
stone chips, fractures or deep scratches in the finish
should be repaired right away. Bare metal will corrode
quickly and may develop into a major repair expense.
Minor chips and scratches can be repaired with touch-up
materials available from your dealer or other service
outlets. Larger areas of finish damage can be corrected
in your dealer’s body and paint shop.
Underbody Maintenance
Chemicals used for ice and snow removal and dust control
can collect
on the underbody. If these are not removed,
accelerated corrosion (rust) can occur on the underbody
parts such as fuel lines, ft-ame, floor pan and exhaust
system even though they have colrosion protection.
At least every spring, flush these materials from the
underbody with plain wate.r. Clean any areas where mud
and other debris can collect. Dirt packed in closed areas
of the frame should be loosened before being flushed.
Your dealer or an underbody car washing system can do
this
for you.
Some weather and atmospheric conditions can create a
chemical fallout. Airborne pollutants can fall upon and
attack painted surfaces
on your vehicle. This damage
can take two forms: blotchy, ringlet-shaped discolorations, and small irregular dark spots etched into
the paint surface.
Although
no defect in the paint job causes this, GM will
repair, at no charge to
the owner, the surfaces of new
vehicles damaged by this fallout condition within
12 months or 12,000 miles (20 000 km) of purchase,
whichever occurs first.
This applies only to materials manufactured and sold by
General Motors. Bodies, body conversions or equipment
not made or sold by General Motors are not covered.
6-68
ProCarManuals.com

Vehicle IdentiP ’* -In N mber (VIN)
- =I I1 11111111 1111 11111111t 111 111111 II 111111111111 111111111 II
ENGINE A98 f ASSEMBLY
CODE- MODEL YEAR PLANT
This is the legal identifier for your vehicle. It appears on
a plate in the front corner
of the instrument panel, on the
driver’s side.
You can see it if you look through the
windshield from outside your vehicle. The VIN also
appears on
the Vehicle Certification and Service Parts
labels and the certificates
of title and registration.
Engine Identification
The 8th character in your VIN is the engine code. This
code will help you identify your engine, specifications
and replacement parts.
Service Parts Identification Label
You’ll find this label on the inside of the glove box. It’s
very helpful if
you ever need to order parts. On this
label is:
your VIN,
the model designation,
0 paint information and
0 a list of all production options and special
Be sure that this label is not removed from the vehicle.
equipment.
Electrical System
Add-on Electrical Equipment
1 NOTICE:
Don’t add anything electrical to your vehicle
unless you check with your dealer first. Some
electrical equipment can damage your vehicle
and the damage wouldn’t be covered
by your
warranty. Some add-on electrical equipment
can keep other components from working as
they should.
Your vehicle has an air bag system. Before attempting to
add anything electrical to your vehicle, see “Servicing
Your Air Bag-Equipped Vehicle”
in the Index.
6-70
ProCarManuals.com

Normal Maintenance Replacement Parts
Replacement part numbers listed in this section are based on the latest information available at the time of printing,
and are subject to change. If a part listed
in this manual is not the same as the part used in your vehicle when it was
built, or
if you have any questions, please contact your GM truck dealer.
These specifications are for information only.
If you have any questions, see the service manual for the chassis or
refer
to the body manufacturer's publications.
VIN Code
Oil Filter';"
Air Cleaner Filter*
PCV Valve*
Spark Plugs*
Fuel Filter*
Wiper Blades**
Wiper Blade Type
Wiper Blade Length
w M
PF52 PF12 18.1
A 1300C??
A 1300C??
CV746C CV796C
4 1-932 4 1-932
GF626 GF626
22154886 22 154886
Trico Trico
18 inches (45.0 cm) 18 inches
(45.0 cm)
"AC part number
**GM part number
?Use
a PF52 oil filter if your vehicle has four-wheel drive.
??A1301C high-capacity air cleaner filter.
R J
PF1218? PF1218
A 1300C?? A 1300C??
CV796C cv774c
4 1-932 4 1-932
GF626 GF626
22 154886 22154886
Trico Trico
18 inches (45.0 cm) I8
inches (45.0 cm)
6-78
ProCarManuals.com