brake GMC YUKON 2005 Workshop Manual

{CAUTION:
Driving through rushing water can be
dangerous. Deep water can sweep your vehicle
downstream and you and your passengers
could drown. If it is only shallow water, it can
still wash away the ground from under your
tires, and you could lose traction and roll the
vehicle over. Do not drive through rushing
water.
SeeDriving in Rain and on Wet Roads on page 4-37for
more information on driving through water.
After Off-Road Driving
Remove any brush or debris that has collected on the
underbody, chassis or under the hood. These
accumulations can be a re hazard.
After operation in mud or sand, have the brake linings
cleaned and checked. These substances can cause
glazing and uneven braking. Check the body structure,
steering, suspension, wheels, tires and exhaust
system for damage. Also, check the fuel lines and
cooling system for any leakage.
Your vehicle will require more frequent service due to
off-road use. Refer to the Maintenance Schedule
for additional information.
4-35

The heavier the rain, the harder it is to see. Even if your
windshield wiper blades are in good shape, a heavy
rain can make it harder to see road signs and traffic
signals, pavement markings, the edge of the road, and
even people walking.
It is wise to keep your wiping equipment in good shape
and keep your windshield washer tank lled with
washer uid. Replace your windshield wiper inserts
when they show signs of streaking or missing areas on
the windshield, or when strips of rubber start to
separate from the inserts.
Driving too fast through large water puddles or even going
through some car washes can cause problems, too.
The water may affect your brakes. Try to avoid puddles.
But if you cannot, try to slow down before you hit them.
{CAUTION:
Wet brakes can cause accidents. They will not
work as well in a quick stop and may cause
pulling to one side. You could lose control of
the vehicle.
After driving through a large puddle of water or
a car wash, apply your brake pedal lightly until
your brakes work normally.
Hydroplaning
Hydroplaning is dangerous. So much water can build up
under your tires that they can actually ride on the
water. This can happen if the road is wet enough and
you are going fast enough. When your vehicle is
hydroplaning, it has little or no contact with the road.
Hydroplaning does not happen often. But it can if your
tires do not have much tread or if the pressure in one or
more is low. It can happen if a lot of water is standing on
the road. If you can see reections from trees, telephone
poles, or other vehicles, and raindrops dimple the water’s
surface, there could be hydroplaning.
Hydroplaning usually happens at higher speeds.
There just is not a hard and fast rule about hydroplaning.
The best advice is to slow down when it is raining.
4-38

If you drive regularly in steep country, or if you are
planning to visit there, here are some tips that can make
your trips safer and more enjoyable. SeeOff-Road
Driving on page 4-21for information about driving
off-road.
Keep your vehicle in good shape. Check all uid
levels and also the brakes, tires, cooling system,
and transmission. These parts can work hard
on mountain roads.
Know how to go down hills. The most important
thing to know is this: let your engine do some of
the slowing down. Shift to a lower gear when you go
down a steep or long hill.
{CAUTION:
If you do not shift down, your brakes could get
so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Shift down
to let your engine assist your brakes on a
steep downhill slope.
{CAUTION:
Coasting downhill in NEUTRAL (N) or with the
ignition off is dangerous. Your brakes will have
to do all the work of slowing down. They could
get so hot that they would not work well. You
would then have poor braking or even none
going down a hill. You could crash. Always
have your engine running and your vehicle in
gear when you go downhill.
Know how to go uphill. You may want to shift down
to a lower gear. The lower gears help cool your
engine and transmission, and you can climb the hill
better.
Stay in your own lane when driving on two-lane
roads in hills or mountains. Do not swing wide
or cut across the center of the road. Drive at speeds
that let you stay in your own lane.
4-44

Your anti-lock brake system (ABS) improves your
vehicle’s stability when you make a hard stop on a
slippery road. Even though you have ABS, you will want
to begin stopping sooner than you would on dry
pavement. SeeAnti-Lock Brake System (ABS) on
page 4-6.
Allow greater following distance on any slippery road.
Watch for slippery spots. The road might be ne until
you hit a spot that is covered with ice. On an
otherwise clear road, ice patches may appear in
shaded areas where the sun cannot reach, such as
around clumps of trees, behind buildings, or under
bridges. Sometimes the surface of a curve or an
overpass may remain icy when the surrounding
roads are clear. If you see a patch of ice ahead of
you, brake before you are on it. Try not to brake while
you are actually on the ice, and avoid sudden
steering maneuvers.
If You Are Caught in a Blizzard
If you are stopped by heavy snow, you could be in a
serious situation. You should probably stay with
your vehicle unless you know for sure that you are near
help and you can hike through the snow. Here are
some things to do to summon help and keep yourself
and your passengers safe:
Turn on your hazard ashers.
Tie a red cloth to your vehicle to alert police that
you have been stopped by the snow.
Put on extra clothing or wrap a blanket around you.
If you do not have blankets or extra clothing, make
body insulators from newspapers, burlap bags,
rags, oor mats — anything you can wrap around
yourself or tuck under your clothing to keep warm.
4-47

Q:What if I want to add heavier equipment to my
vehicle?
A:You can add heavier equipment on the front of the
vehicle if you compensate for it by carrying fewer
passengers, less cargo, or by positioning cargo
towards the rear. This has the effect of reducing the
load on the front. However, the front GAWR, rear
GAWR and the gross vehicle weight rating (GVWR)
must never be exceeded.
{CAUTION:
On some vehicles equipped with certain front
mounted equipment, such as a snow plow, it
may be possible to load the front axle to the
front GAWR but not have enough weight on
the rear axle to have proper braking
performance. If your brakes can not work
properly, you could have a crash. To help your
brakes work properly when a snow plow is
installed, always follow the snow plow
manufacturer or installer’s recommendation for
rear ballast to ensure a proper front and rear
weight distribution ratio, even though the
actual front weight may be less than the front
GAWR, and the total vehicle weight is less
than the GVWR. Maintaining a proper front and
rear weight distribution ratio is necessary to
provide proper braking performance.
4-60

Four-Wheel-Drive Vehicles (NR4 and NP8)
Use the following procedure to tow your vehicle:
1. Shift the transmission to PARK (P).
2. Turn the engine off, but leave the ignition on.
3. Firmly set the parking brake.
4. Securely attach the vehicle being towed to the tow
vehicle.
{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
5. Shift the transfer case to NEUTRAL (N). See
Four-Wheel Drive on page 2-27orAll-Wheel
Drive with StabiliTrak
®on page 2-31for the proper
procedure to select the NEUTRAL (N) position
for your vehicle.
6. Release the parking brake only after the vehicle
being towed is rmly attached to the towing
vehicle.
7. Turn the ignition off.
4-63

Dolly Towing
Two-Wheel-Drive Vehicles
Notice:If you tow a two-wheel-drive vehicle with
the rear wheels on the ground, the transmission
could be damaged. The repairs would not be
covered by your warranty. Never tow your vehicle
with the rear wheels on the ground.
Two-wheel-drive vehicles should not be towed with the
rear wheels on the ground. Two-wheel-drive
transmissions have no provisions for internal lubrication
while being towed.
Two-wheel-drive vehicles can be towed on a dolly with
the front wheels on the ground provided that the wheels
are straight and the steering column has been locked.
Four-Wheel-Drive Vehicles
If your vehicle is equipped with StabiliTrak®,itisnot
designed to be dolly towed. If you need to tow your
vehicle, see “Dinghy Towing” earlier in this section.If your vehicle is not equipped with StabiliTrak®, use the
following procedure to tow your vehicle:
1. Drive the vehicle up onto the tow dolly.
2. Shift the transmission to PARK (P).
3. Turn the engine off, but leave the ignition on.
4. Firmly set the parking brake.
5. Securely attach the vehicle being towed to the
tow dolly.
4-64

{CAUTION:
Shifting a four-wheel-drive vehicle’s transfer
case into NEUTRAL can cause your vehicle to
roll even if the transmission is in PARK (P).
You or others could be injured. Make sure the
parking brake is rmly set before you shift the
transfer case to NEUTRAL.
6. Shift the transfer case to NEUTRAL. See
Four-Wheel Drive on page 2-27for the proper
procedure to select the NEUTRAL position for your
vehicle.
7. Release the parking brake only after the vehicle
being towed is rmly attached to the towing vehicle.
8. Turn the ignition off and lock the steering column.
Level Control
Automatic Level Control
The automatic level control rear suspension is available
on C/K 1500 vehicles and comes as a part of the
Autoride
®suspension, if equipped.
This type of level control is fully automatic and will
provide a better leveled riding position as well as better
handling under a variety of passenger and loading
conditions. An air compressor connected to the rear
shocks will raise or lower the rear of the vehicle
to maintain proper vehicle height. The system is
activated when the ignition key is turned to RUN and
will automatically adjust vehicle height thereafter.
The system may exhaust (lower vehicle height) for up to
ten minutes after the ignition key has been turned off.
You may hear the air compressor operating when
the height is being adjusted.
If a self-equalizing hitch is being used, it is
recommended to allow the shocks to inate, thereby
leveling the vehicle prior to adjusting the hitch.
4-65

Autoride®
If equipped, the Autoride®feature will provide a superior
vehicle ride and handling under a variety of passenger
and loading conditions.
The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/dive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride
®also interacts with the tow/haul switch that,
when engaged, will provide additional control of the
shock absorbers. This additional control results in better
ride and handling characteristics when the vehicle is
loaded or towing a trailer. SeeTow/Haul Mode Light on
page 3-53for more information.
Trailer Recommendations
You must subtract your hitch loads from the Cargo
Weight Rating (CWR) for your vehicle. CWR is the
maximum weight of the load your vehicle can carry. It
doesn’t include the weight of the people inside. But you
can gure about 150 lbs. (68 kg) for each seat. The total
cargo load must not be more than your vehicle’s CWR.
Weigh your vehicle with the trailer attached, so that you
won’t go over the GVWR or GAWR. If you are using
a weight-distributing hitch, weigh the vehicle without the
spring bars in place.
You’ll get the best performance if you spread out the
weight of your load the right way, and if you choose the
correct hitch and trailer brakes.
For more information, seeTowing a Trailer on page 4-67.
4-66

Towing a Trailer
Do not tow a trailer during break-in. SeeNew Vehicle
Break-In on page 2-19for more information.
{CAUTION:
If you do not use the correct equipment and
drive properly, you can lose control when you
pull a trailer. For example, if the trailer is too
heavy, the brakes may not work well — or even
at all. You and your passengers could be
seriously injured. Pull a trailer only if you have
followed all the steps in this section. Ask your
dealer for advice and information about towing
a trailer with your vehicle.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.
To identify the vehicle trailering capacity of your vehicle,
you should read the information in “Weight of the
Trailer” 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 acceleration, braking, 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.
4-67