1997 CHEVROLET TAHOE service

Downloaded from www.Manualslib.com manuals search engine Be sure the posted octane is at least 87. If the octane is
less than
87, you may get a heavy knocking noise when
you drive. If it’s bad enough, it can damage your engine.
If you’re using fuel rated at
87 octane or higher and you
still hear heavy knocking, your engine needs service.
But don’t worry if you hear a little pinging noise when
you’re accelerating or driving up a hill. That’s normal,
and you don’t have to buy a higher octane fuel to get rid
of pinging. It’s the heavy, constant knock that means
you have a problem.
If your vehicle is certified to meet California Emission
Standards (indicated on the underhood tune-up label),
it is designed to operate on fuels that meet California
specifications. If such fuels are not available in states
adopting California emissions standards, your vehicle
will operate satisfactorily on fuels meeting federal
specifications, but emission control system performance
may be affected. The malfunction indicator lamp on your instrument
panel may
turn on and/or your vehicle
may fail a smog-check test. If this occurs, return to your
authorized GM dealer for diagnosis to determine the
cause of failure. In the event it is determined that the
cause of the condition is the type of fuels used, repairs
may not be covered by your warranty.
Some gasolines that are not reformulated for low
emissions contain an octane-enhancing additive called
methylcyclopentadlenyl manganese tricarbonyl (MMT);
ask your service station operator whether or not his fuel
contains
MMT. General Motors does not recommend the
use of such gasolines. If fuels containing MMT are used,
spark plug life may be reduced and your emission
control system performance may be affected. The
malfunction indicator lamp on your instrument panel
may turn on. If this occurs, return to your authorized
GM dealer for service.
6-4

Downloaded from www.Manualslib.com manuals search engine Engine Oil Additives
Don’t add anything to your oil. Your GM dealer is ready
to advise if you think something should be added.
When to Change Engine Oil
If any one of these is true for you, use the short triplcity
maintenance schedule:
0
0
0
0
0
Most trips are less than 5 to 10 miles (8 to 16 km).
This is particularly important when outside
temperatures are below freezing.
Most trips include extensive idling (such as frequent
driving in stop-and-go traffic).
You operate your vehicle in dusty areas or
off-road frequently.
You frequently tow a trailer or use a carrier on top of
your vehicle.
The vehicle is used for delivery service, police, taxi
or other commercial application.
Driving under these conditions causes engine oil to
break down sooner. If any one of these is true for your
vehicle, then you need to change your oil and filter
every
3,000 miles (5 000 km) or 3 months -- whichever
occurs first. If
none
of them is true, use the long triphighway
maintenance schedule. Change the oil and filter every
7,500 miles (12 500 km) or 12 months -- whichever
occurs first. Driving a vehicle with a fully warmed
engine under highway conditions causes engine oil to
break down slower.
What to Do with Used Oil
Did you know that used engine oil contains certain
elements that may be unhealthy for your skin and could
even cause cancer? Don’t let used oil stay on your skin
for very long. Clean your skin and nails with soap and
water, or a good hand cleaner. Wash or properly throw
away clothing or rags containing used engine oil. (See
the manufacturer’s warnings about the use and disposal
of oil products.)
Used oil can be a real threat to the environment. If you
change your own oil, be sure to drain all free-flowing oil
from the filter before disposal. Don’t ever dispose of
oil
by putting it in the trash, pouring it on the ground,
into sewers, or into streams or bodies
of water. Instead,
recycle it by taking
it to a place that collects used oil. If
you have a problem properly disposing
of your used oil,
ask your dealer, a service station or a local recycling
center for help.
6-17

Downloaded from www.Manualslib.com manuals search engine Air Cleaner (Gasoline Engines)
Your air cleaner is located between the battery and
coolant recovery tank. The air cleaner assembly
has an
indicator that lets
you know when the air
filter is dirty and needs
to be serviced.
The indicator is located in the air intake tube between
the air cleaner and the engine. See “Owner Checks and
Services” in the Index to determine when to check
the indicator.
If the area inside the clear section
of the indicator is
green, no air filter service is required. When the area
inside
the indicator is orange and CHANGE AIR
FILTER appears, the filter should be replaced.

Downloaded from www.Manualslib.com manuals search engine To remove the air filter, unhook the retainer clips and
remove the cover. Lift the filter and the connected duct
out of the air cleaner housing. Hold the duct and remove
the filter by both pulling and twisting the filter away
from the duct. Care should be taken to dislodge as little
dirt as possible.
Clean the filter sealing surface of the duct and the
filter housing. Install
the new filter by pushing it all the way to the stop
on the duct.
Install the duct and the filter into the air cleaner housing.
Make sure that the duct fits properly into the housing.
Install the cover and fasten the two retaining clips.
After the air filter is properly serviced, the indicator
should be reset. Push the button on top
of the indicator
to reset
it to the green (clean) filter zone.
6-19

Downloaded from www.Manualslib.com manuals search engine Refer to the Maintenance Schedule to determine when to
replace the
air filter. See “Owner Checks and Services”
in the Index.
A 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
backfhes.
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.
NOTICE:
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
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 is mainly driven under one or
more
of these conditions:
0 In heavy city traffic where the outside temperature
regularly reaches
90°F (32 “C) or higher.
In hilly or mountainous terrain.
When doing frequent trailer towing.
0 Uses such as found in taxi, police or delivery service.
If you do not use your vehicle under any of these
conditions, the fluid and filter do not require changing.
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.

Downloaded from www.Manualslib.com manuals search engine Rear Axle
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 What to Use
Refer
to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants” in the Index.
Four-wheel Drive
Most lubricant checks in this section also apply to
four-wheel-drive vehicles. However, they have
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 “Periodic Maintenance
Inspections” in the Index.
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.
6-24

Downloaded from www.Manualslib.com manuals search engine How to Check Lubricant Front Axle
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.
What to Use
Refer to the Maintenance Schedule to determine what
kind of lubricant to use. See “Recommended Fluids and
Lubricants” in the Index.
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.
6-25

Downloaded from www.Manualslib.com manuals search engine NOTICE:
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
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:
r
Continuing to drive with worn-out brake pads
could result in costly brake repair.
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 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.