1993 GMC SIERRA brakes

D (Third Gear)
This is like
OD, but you never go into Overdrive. You should use D when
towing a trailer, carrying a heavy load, driving on steep hills, or for off-road
driving.
2 (Second Gear)
This position gives you more power but lower fuel economy. You can use
2
on hills. It can help control your speed as you go down steep mountain
roads, but then you would also want to use your brakes
off and on.
If you manually select 2, the transmission will drive in second gear. You may
use this feature for reducing torque to the rear wheels when you are trying
to
start your vehicle from a stop on slippery road surfaces.
1 (First Gear)
This position gives you even more power (but lower fuel econo\
my) than
2.
You can use it on very steep hills, or in deep snow or mud. If the selector
lever
is put in 1, the transmission won’t shift into first gear until the vehic\
le is
going slowly enough.
NWTIGE
If your rear wheels can’t rotate, don’t try to drive. This might happen if
you were stuck in very deep sand or mud or were up against a. solid
object. You could damage your transmission.
AWZ , <,*,~l,<.,. ...
Also, if you stop when going uphill, don’t hold your vehic there with only the
accelerator pedal.
This could overheat and damage ,the transmission. Use your
brakes or shii into P (Park) to hdd your vehicle in position on a hill.
.,$*’,,&:&> ._,, , . ~ ~ ,>&:a
2-23
ProCarManuals.com

Parking Brake
K2221
To set the parking brake:
Hold the regular brake pedal down with your right foot. Push down the
parking brake pedal with your left
foot. If the ignition is on, the brake system
warning light will come
on.
To release the parking brake:
Hold the regular brake pedal down. Pull the lever marked RELEASE.
Driving with the parking brake on can cause your rear brakes to overheat.
You may have to replace them, and you also da other p;
of I
your vehicle.
’ ‘
If you are on a hill:
See “Parking on Hills” in the Index. That part shows how to turn your front
wheels.
If you are towing a trailer and are parking on any hill:
See “Towing a Trailer” in the Index. That part shows what to do first to keep
the trailer from moving.
2-29
ProCarManuals.com

Features & Contmls
Four- Wheel Drive
CAUTION I
It can be dangerous to get out of your vehicle if the shift lever -is not
fully in
P (Park) with the parking brake firmly set. Your vehicle can
roll. Don’t leave your vehicle when the engine is running unless you
have
to. If you’ve left the engine running, the vehicle can ‘move
suddenly. You or -others could be injured.
To be sure your vehicle
won’t move, even when you’re on fairly level ground, always
set your
parking brake and move the shift lever
to P (Park).
If you have four-wheel drive and your transfer case is in N (Neutral),
your vehicle
will be free to roll, even if your shift lever is in P’(Park).
So, be sure the transfer case is in a drive gear-not in N (Neutral).
Follow the proper steps
to be suce your vehicle won’t move. See
“Shifting Into
P (Park)” in the Index.
If you are parking on a hill, or if you’re pulling a trailer, also see
“Parking ‘on Hills’’ or “Towing a Trailer” in this section.
I
If your vehicle has four-wheel drive, you can send your engine’\
s driving power
to all four wheels for extra traction. To get the most satisfaction out of
four-wheel drive, you must be familiar with it’s operation. \
Read the part that
follows before using four-wheel drive. You should use
2H for most normal
driving conditions.
Rear-wheel antilock brakes
do not work when you shift into four-wheel drive.
Your regular brakes will still work. When you shift back into two-w\
heel drive,
your rear-wheel antilock brakes will take over again.
I NOTICE
Driving in the 4H or 4L positions for a long time on dry or wet pavement
could shorten the life
of your vehicle’s drivetrain.
2-36
ProCarManuals.com

When using concentrated washer flui
follow the manufacturer’s
instructions for adding water.
Don’t mix water with ready-to-use washer fluid. Water can ca\
use the
solution
to freeze and damage your washer fluid tank and other parts
of the washer system.
Also, water dc ;n’t clean as well as washer
fluid.
allows for expansion, which could damage the tank
if it is completely
full.
’
I
Fill your washer fluid tank only 314 full when it’s very cold. This
Don’t use radiator antifreeze in your windshield washer. It can
damaae your washer system and paint.
Cruise Control (Option)
K2247
With Cruise Control, you can maintain a speed of about 25 mph (40 km/h) or
more without keeping your foot on the accelerator. This can re\
ally help on
long trips. Cruise Control does not work at speeds below about 25 mph
(40 km/h).
When you apply your brakes, or push the clutch pedal, if you \
have
a manual
transmission, the Cruise Control shuts
off.
2-47
ProCarManuals.com

you know they’re working. If you are familiar. with this section, you should not
be alarmed when this happens.
Gages can indicate when there may be or is _a problem with one of your
vehicle’s functions. Often gages and warning lights work together
to let you
know when there’s a problem with your vehicle.
When one of the warning lights comes on and stays on when yo\
u are driving, or when one of the gages shows there may be a probl\
em, check the
section that tells you what to do about it. Please follow the\
manual’s advice.
Waiting to do repairs can be costly-and even dangerous.
So please get to
know your warning lights and gages. They’re a big help.
Brake System. Warning Light
BRAKE
. , K2325
Your vehicle’s hydraulic brake system is divided into two parts. If ,one‘ part
isn’t working, the other part can still work and stop you. \
For good braking,
though, you need both- systems working well.
Your vehicle also has rear-wheel antilock brakes.
If the warning light goes on,
there could be a brake problem with either your regular or rear wheel antilock
brakes, or both. Have your brake system inspected right away.
This light should come on as you start the vehicle.
If it doesn’t come on
then, have
it fixed so it will be ready to warn you if there’s a problem.
This light
will also come on when you set your parking brake, and will stay
on
if your parking brake doesn’t release fully. If it stays on after your parking
brake is fully released,
it means you may ‘have a brake problem. If the light
comes on while driving, pull
off the road and stop carefully. You may notice
2-79
ProCarManuals.com

Your Driving and the Road
Control of a Vehicle
You have three systems that make your vehicle go where you want it to go.
They are the brakes, the steering and the accelerator.
All three systems have
to
do their work at the places where the tires meet the road.
AM409002
Sometimes, as when you’re driving on snow or ice, it’s e\
asy to ask more of
those control systems than the tires and road can provide. Tha\
t means you can
lose control of your vehicle.
Braking
Braking action involves perception time and reaction time.
First, you have to decide to push on the brake pedal. That’s perception
time.
Then you have to bring up your foot and do it. That’s reaction time.
Average reaction time is about 314 of a second. But that’s only an average.
It might be less with one driver and as long as two or thre\
e seconds or
more with another. Age, physical condition, alertness, coordinati\
on, and
eyesight all play a part.
So do alcohol, drugs and frustration. But even in 3/4
of a second, a vehicle moving at 60 mph (100 km/h) travels 66 feet (20 m).
That could be a lot
of distance in an emergency, so keeping enough space
between your vehicle and others
is important.
And, of course, actual stopping distances vary greatly with the surface of the
road (whether it’s pavement or gravel); the condition of the road (wet, dry,
icy): tire tread; and the condition of your brakes,
4-1 4
ProCarManuals.com

Most drivers treat their brakes with care. Some, however, overw\
ork the
braking system with poor driving habits.
Avoid needless heavy braking. Some people drive in spurts-heavy
acceleration followed by heavy braking-rather than keeping pace with
traffic. This is
a mistake. Your brakes may not have time to cool
between hard stops. Your brakes will wear out much faster
if you do a
lot of heavy braking.
Don’t “ride” the brakes by letting your left foot rest\
lightly on the brake
pedal while driving.
I
I
AM410001
CAUTION I
1 “Riding” your brakes can cause them to overheat to the point that
- they won’t work well. You might not be able to stop your vehicle in
time to avoid an accident. If you “ride” your brakes, they will get
so
hot they will require a lot of pedal force to slow you down. Avoid
“riding” the brakes.
NOTICE
“Riding” the brakes wears them out much faster. You would need costly
brake replacement much sooner than normal. and it also reduces fuel
economv.
4-1 5
ProCarManuals.com

If you keep pace with the traffic and alllow realieti~ following dbtances, ‘you
will eliminate a lot .of unnecessary braking.. That means - better brakin’g . and
longer brake life;
,* If your engine ever stops while- you’re driving, brake normally but don’t
pump your brakes. If you do, tht$ pedal may get harder to. .push down. If
your- engine stops, you will still have some power $rake, assist But you
will use it when you brake. Once the power assist =is used ‘up, it may
take longer to stop and the brake pedal will be harder to push.
Anti-lock Brakes (ABS)
Your vehicl’e has an ‘advanced electronic braking system that can help keep it
under Control.
When you turn your key on you m.ay .hear a momentary clicking ngise. , ,.
Here’s I how anti-lock .works. Let’s say the road is wet. You’re d.rivilng. sifely.
Suddenly an animal jumps out In frqnt of you.
ProCarManuals.com