maintenance GMC YUKON 2002 User Guide

4-56
NOTICE:
Pulling a trailer improperly can damage your
vehicle and result in costly repairs not covered by
your warranty. To pull a trailer correctly, follow
the advice in this part, and see your dealer for
important information about towing a trailer with
your vehicle. Additional rear axle maintenance is
required for a vehicle used to tow a trailer. See
ªScheduled Maintenance Servicesº in the Index.
To identify what the vehicle trailering capacity is for
your vehicle, you should read the information in
ªWeight of the Trailerº that appears later in this section.
If yours was built with trailering options, as many are,
it's ready for heavier trailers. But trailering is different
than just driving your vehicle by itself. Trailering means
changes in handling, durability and fuel economy.
Successful, safe trailering takes correct equipment, and
it has to be used properly.
That's the reason for this part. In it are many
time
-tested, important trailering tips and safety rules.
Many of these are important for your safety and that of
your passengers. So please read this section carefully
before you pull a trailer.
If You Do Decide To Pull A Trailer
If you do, here are some important points:

There are many different laws, including speed limit
restrictions, having to do with trailering. Make sure
your rig will be legal, not only where you live but
also where you'll be driving. A good source for this
information can be state or provincial police.

Consider using a sway control if your trailer will
weigh less than 5,000 lbs. (2 270 kg). You should
always use a sway control if your trailer will weigh
more than 5,000 lbs. (2 270 kg). You can ask a hitch
dealer about sway controls.

Don't tow a trailer at all during the first 500 miles
(800 km) your new vehicle is driven. Your engine,
axle or other parts could be damaged.

Then, during the first 500 miles (800 km) that you
tow a trailer, don't drive over 50 mph (80 km/h) and
don't make starts at full throttle. This helps your
engine and other parts of your vehicle wear in at the
heavier loads.

4-69 Maintenance When Trailer Towing
Your vehicle will need service more often when you're
pulling a trailer. See the Maintenance Schedule for more
on this. Things that are especially important in trailer
operation are automatic transmission fluid (don't
overfill), engine oil, axle lubricant, belt, cooling system
and brake system. Each of these is covered in this
manual, and the Index will help you find them quickly.
If you're trailering, it's a good idea to review these
sections before you start your trip.
Check periodically to see that all hitch nuts and bolts
are tight.
Trailer Wiring Harness
Your vehicle is equipped with the following wiring
harnesses for towing a trailer.Basic Trailer Wiring Package
The trailer wiring harness, with a seven-pin connector,
is located at the rear of the vehicle and is tied to the
vehicle's frame. The harness connector can be plugged
into a seven
-pin universal heavy-duty trailer connector
available through your dealer.

6-
6-1
Section 6 Service and Appearance Care
Here you will find information about the care of your vehicle. This section begins with service and fuel information,
and then it shows how to check important fluid and lubricant levels. There is also technical information about your
vehicle, and a part devoted to its appearance care.
6
-2 Service
6
-3 Fuel (Gasoline)
6
-5 Fuel E-85 (85% Ethanol)
6
-7 Fuels in Foreign Countries
6
-7 Filling Your Tank
6
-9 Filling a Portable Fuel Container
6
-10 Checking Things Under the Hood
6
-15 Engine Oil
6
-21 Engine Air Cleaner/Filter
6
-23 Passenger Compartment Air Filter
(If Equipped)
6
-24 Automatic Transmission Fluid
6
-27 Rear Axle
6
-28 Four-Wheel Drive
6
-31 Engine Coolant
6
-34 Coolant Surge Tank Pressure Cap6
-35 Power Steering Fluid
6
-36 Windshield Washer Fluid
6
-37 Brakes
6
-41 Battery
6
-42 Bulb Replacement
6
-48 Windshield Wiper Blade Replacement
6
-49 Tires
6
-59 Appearance Care
6
-60 Cleaning the Inside of Your Vehicle
6
-63 Cleaning the Outside of Your Vehicle
6
-67 GM Vehicle Care/Appearance Materials
6
-68 Vehicle Identification Number (VIN)
6
-69 Electrical System
6
-77 Replacement Bulbs
6
-78 Capacities and Specifications
6
-81 Normal Maintenance Replacement Parts

6-2
Service
Your dealer knows your vehicle best and wants you to
be happy with it. We hope you'll go to your dealer for
all your service needs. You'll get genuine GM parts and
GM
-trained and supported service people.
We hope you'll want to keep your GM vehicle all GM.
Genuine GM parts have one of these marks:
Doing Your Own Service Work
If you want to do some of your own service work, you'll
want to use the proper service manual. It tells you much
more about how to service your vehicle than this manual
can. To order the proper service manual, see ªService
and Owner Publicationsº in the Index.
Your vehicle has an air bag system. Before attempting to
do your own service work, see ªServicing Your Air
Bag
-Equipped Vehicleº in the Index.
You should keep a record with all parts receipts and list
the mileage and the date of any service work you
perform. See ªMaintenance Recordº in the Index.

6-3
CAUTION:
You can be injured and your vehicle could be
damaged if you try to do service work on a
vehicle without knowing enough about it.

Be sure you have sufficient knowledge,
experience, the proper replacement parts
and tools before you attempt any vehicle
maintenance task.

Be sure to use the proper nuts, bolts and
other fasteners. ªEnglishº and ªmetricº
fasteners can be easily confused. If you use
the wrong fasteners, parts can later break
or fall off. You could be hurt.
Adding Equipment to the Outside of
Your Vehicle
Things you might add to the outside of your vehicle can
affect the airflow around it. This may cause wind noise
and affect windshield washer performance. Check with
your dealer before adding equipment to the outside of
your vehicle.
Fuel (Gasoline)
The 8th digit of your vehicle identification number
(VIN) shows the code letter or number that identifies
your engine. You will find the VIN at the top left of the
instrument panel. See ªVehicle Identification Numberº
in the Index.
If your vehicle has the 5.3L V8 engine (VIN Code Z
only), you may use either regular unleaded gasoline or
ethanol fuel containing up to 85% ethanol (E
-85); also
see ªFuel E
-85 (85% Ethanol)º following. In all other
engines, including the 5.3L V8 (VIN Code T), use only
regular unleaded gasoline.
Gasoline Octane
Use regular unleaded gasoline with a posted octane of
87 or higher. If the octane is less than 87, you may get a
heavy knocking noise when you drive. If it is bad
enough, it can damage your engine. A little pinging
noise when you accelerate or drive uphill is considered
normal. This does not indicate a problem exists or that a
higher
-octane fuel is necessary.

6-22
1. To remove the engine/air cleaner filter, loosen the
screws on the housing cover.
2. Then lift the cover upward and remove the filter
from the housing. Care should be taken to dislodge
as little dirt as possible.
3. Clean the filter sealing surface and the filter housing.
4. Install the new filter.
5. Reinstall the housing cover.Refer to the Maintenance Schedule to determine when to
replace the air filter. See ªOwner Checks and Servicesº
in the Index.
CAUTION:
Operating the engine with the air cleaner/filter
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/filter off.
NOTICE:
If the air cleaner/filter 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/filter in place when
you're driving.

6-23
Passenger Compartment Air Filter
(If Equipped)
Your vehicle may be equipped with a passenger
compartment air filter. The filter is located under the
instrument panel, below the glove compartment.
Your vehicle may or may not be equipped with an
access panel.
To replace the passenger compartment air filter, do
the following:
1. If your vehicle has an access panel, remove the bolts
on it and set the panel aside. If your vehicle does not
have the access panel, skip this step.
2. Next, pull
downward on the filter
retaining bracket.3. Remove the air filter by pulling downward on the
element. Remove the second portion of the air filter
by sliding it towards the rear of the vehicle and then
pulling downward.
4. Install the new filter by reversing the steps listed
previously. Be sure to follow any instructions that
may be included in the replacement filter package.
Because this procedure can be a little difficult,
you may choose to have it done at your dealer's
service department.
Refer to the Maintenance Schedule to determine when to
replace the passenger compartment air filter. See
ªScheduled Maintenanceº in the Index.

6-24
Automatic Transmission Fluid
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 90F (32C) or higher.

In hilly or mountainous terrain.

When doing frequent trailer towing.

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 ªScheduled Maintenance Servicesº in the Index.
How to Check
Because this operation can be a little difficult, you
may choose to have this done at the 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.
Too little fluid could cause the transmission to
overheat. Be sure to get an accurate reading if
you check your transmission fluid.

6-27 How to Add Fluid
Refer to the Maintenance Schedule to determine what
kind of transmission fluid to use. See ªRecommended
Fluids and Lubricantsº in the Index.
Add fluid only after checking the transmission fluid
while it is hot. (A cold check is used only as a
reference.) If the fluid level is low, add only enough of
the proper fluid to bring the level up to the HOT area for
a hot check. It doesn't take much fluid, generally less
than one pint (0.5 L). Don't overfill.
NOTICE:
We recommend you use only fluid labeled
DEXRON-III, because fluid with that label is
made especially for your automatic transmission.
Damage caused by fluid other than
DEXRON
-III is not covered by your new
vehicle warranty.

After adding fluid, recheck the fluid level as
described under ªHow to Check.º

When the correct fluid level is obtained, push the
dipstick back in all the way; then flip the handle
down to lock the dipstick in place.
Rear Axle
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªScheduled
Maintenance Servicesº in the Index.

6-28 How to Check Lubricant
1500 Series shown, 2500 and 3500 Series similar
To get an accurate reading, the vehicle should be on a
level surface.
The proper level for the 1500 Series is from 5/8 inch to
1 5/8 inch (15 mm to 40 mm) below the bottom of the
filler plug hole. The proper level for the 2500 Series is
from 0 to 3/8 inch (0 to 10 mm) below the bottom of the
filler plug hole. Add only enough fluid to reach the
proper level.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See ªRecommended Fluids and
Lubricantsº in the Index.
Four-Wheel Drive
Lubricant checks in this section also apply to these
vehicles. However, there are two additional systems that
need lubrication.
Transfer Case
When to Check Lubricant
Refer to the Maintenance Schedule to determine how
often to check the lubricant. See ªPeriodic Maintenance
Inspectionsº in the Index.