GMC YUKON 1999 Owner's Manual

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Brakes
Brake Fluid
Your brake master cylinder
reservoir is here. It is filled
with DOT
-3 brake fluid.
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 your brake
system fixed, since a leak means that sooner or later your
brakes won't work well, or won't work at all.So, it isn't a good idea to ªtop offº your brake fluid.
Adding brake fluid won't correct a leak. If you add fluid
when your linings are worn, then you'll 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 fluid, it can spill on
the engine. The fluid will burn if the engine is
hot enough. You or others could be burned,
and your vehicle could be damaged. Add brake
fluid only when work is done on the brake
hydraulic system.
Refer to the Maintenance Schedule to determine when to
check your brake fluid. See ªPeriodic Maintenance
Inspectionsº in the Index.

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Checking Brake Fluid
You can check the brake fluid without taking off the cap.
Just look at the brake fluid reservoir. The fluid level
should be above MIN. If it isn't, have your 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.What to Add
When you do need brake fluid, use only DOT
-3 brake
fluid. Refer to ªRecommended Fluids and Lubricantsº
in the Index. Use new brake fluid from a sealed
container only.
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 fluid in your brake
system, your brakes may not work well, or they
may not even work at all. This could cause a
crash. Always use the proper brake fluid.

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NOTICE:

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 ªAppearance Careº in
the Index.
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).
CAUTION:
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.
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.

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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 ªBrake System Inspectionº in Section 7 of this
manual under Part C ªPeriodic Maintenance
Inspections.º
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.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
If your brake pedal goes down farther than normal, your
rear drum brakes may need adjustment. Adjust them by
backing up and firmly applying the brakes a few times.
Replacing Brake System Parts
The braking system on a modern 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
GM brake parts. When you replace parts of your braking
system
-- for example, when your brake linings wear
down and you have to have new ones put in
-- be sure
you get new approved GM replacement parts. If you
don't, your brakes may no longer work properly. For
example, if someone puts in brake linings that are wrong
for your vehicle, the balance between your front and
rear brakes can change
-- for the worse. The braking
performance you've come to expect can change in many
other ways if someone puts in the wrong replacement
brake parts.

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Fluid Leak Check
After the vehicle has been parked for awhile, inspect the
surface under the vehicle for water, oil, fuel or other
fluids. Water dripping from the air conditioning system
after it has been used is normal. If you notice fuel leaks
or fumes, the causes should be found and corrected
at once.
Battery
Your new vehicle has an ACDelco Freedom
battery.
When it's time for a new battery, we recommend an
ACDelco Freedom battery. Get one that has the
replacement number shown on the original
battery's label.
Vehicle Storage
If you're not going to drive your vehicle for 25 days or
more, remove the black, negative (
-) cable from the
battery. This will help keep your battery from
running down.
CAUTION:
Batteries have acid that can burn you and gas
that can explode. You can be badly hurt if you
aren't careful. See ªJump Startingº in the Index
for tips on working around a battery without
getting hurt.
Contact your dealer to learn how to prepare your vehicle
for longer storage periods.
Also, for your audio system, see ªTheft
-Deterrent
Featureº in the Index.

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Bulb Replacement
Before you replace any bulbs, be sure that all the lamps
are off and the engine isn't running. For the proper bulb
type, see ªReplacement Bulbsº in the Index. For any
bulb changing procedure not listed in this section,
contact your dealer's service department.
Halogen Bulbs
CAUTION:
Halogen bulbs have pressurized gas inside and
can burst if you drop or scratch the bulb. You or
others could be injured. Be sure to read and
follow the instructions on the bulb package.
Headlamps
Parking/Turn Signal Lamp Removal
1. Remove the two phillips-head screws on the side of
the parking/turn signal bulb assembly. The
parking/turn signal assembly must be removed to
provide clearance for headlamp removal.
2. Pull the parking/turn signal assembly toward the side
of the vehicle until the tabs are out of the grille.

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A. Turn Signal Bulb
B. Sidemarker Bulb
3. To remove a bulb, turn the socket counterclockwise
to remove it from the assembly.
4. Install the parking/turn signal lamp assembly by
sliding it from the side of the vehicle toward the
center until the tabs fully engage the grille.
5. Install and tighten the two phillips
-head screws.Headlamp Removal
1. Remove the parking/turn signal assembly as
described previously.
2. Remove the two turn signal bulb sockets and the
sidemarker bulb socket from the parking/turn signal
assembly by turning them counterclockwise.
3. Set the parking/turn signal assembly to the side.4. Remove the two bolts at the top of the radiator
support as shown.
5. Pull the headlamp assembly out.

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6. Turn the bulb counterclockwise and remove it.
7. Unplug the electrical connector.
8. Put the new bulb into the lens assembly and turn it
clockwise until it is tight.
9. Plug in the electrical connector.
10. Put the headlamp lens assembly back into the
vehicle. Install and tighten the two bolts.
11. Install the two turn signal bulb sockets and the
sidemarker bulb socket into the parking/turn signal
bulb assembly.
12. Install the parking/turn signal assembly. Install and
tighten the two phillips
-head screws.
Parking/Turn Signal Lamps
For the procedure to remove the parking/turn signal
lamps and sidemarker lamps, see ªHeadlampsº
previously in this section.
Fog Lamps
1. The fog lamp bulb assembly is located under the
front bumper.
2. Remove the fog lamp bulb socket by turning it
counterclockwise.

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3. Remove the connector from the bulb by lifting the
tabs on the sides of the connector.
4. Insert the new bulb into the connector until the tabs
lock into the connector.
5. Insert the fog lamp bulb socket into the fog lamp
housing and turn it clockwise one
-quarter of a turn.
Center High-Mounted Stoplamp (CHMSL)
The individual bulbs in the CHMSL are not replaceable.
See your dealer for assistance.
Rear Lamps
1. Open the tailgate or rear doors.
2. Remove the two black plastic plugs from the rear
lamp assembly access holes.
3. Remove the two rear
lamp assembly screws
inside the fender and
pull out the lamp
assembly. You may want
to use a magnetic
screwdriver when
removing the screws.

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4. Remove the screws from
the bulb retainer and
take the bulb retainer off
of the lamp assembly.
5. Pull the old bulb straight out of the socket.
6. Put in a new bulb and push it straight in until it
is tight.
7. Replace the bulb retainer.
8. Replace the rear lamp assembly and tighten the
screws. You may want to use a magnetic screwdriver
when installing the screws.
9. Close the tailgate or rear doors.Windshield Wiper Blade Replacement
Windshield wiper blades should be inspected at least
twice a year for wear and cracking. See ªWiper Blade
Checkº in Section 7 of this manual under Part B ªOwner
Checks and Servicesº for more information.