1994 GMC SIERRA brake

If you are going to drive the vehicle, shift the transmission into th\
e gear
you want. Then shift the transfer case into the range you want, apply
the regular brakes and release the parking brake.
When you release the clutch, the power take-off will start.
5. Release the clutch (and the regular brakes) as you normally \
would.
Using a Transfer Case Mounted Power Take-Off
(Automatic Transmission)
1. Set the parking brake.
2. Shift the transfer case into “N’ (Neutral).
3. Shift the transmission into “N’ (Neutral).
4. Engage the power take-off.
If you are going to drive the vehicle, shift the transfer case into \
the
range you want. Then apply the regular brakes and release
the parking
brake.
5. Shift the transmission to “D” (Drive) to start the powe\
r take-off.
6. Release the regular brakes to drive the vehicle.
Towing a Trailer
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 section, and see your Veh\
icle
dealer for important information about towing a trailer with
your vehicle.
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from the front edge of the foot to the middle of the hitch ball socket. If
the distance is less than 12 inches, take the foot off the trailer tongue.
0 If you’ll be pulling a trailer that, when loaded, will weigh more than
4,000 pounds (1 8 14 kg) be sure to use a properly mounted,
weight-distributing hitch and sway control
of the proper size. This
equipment is very important for proper vehicle loading and good
handling
when you’re driving.
Safety Chains
You should always attach chains between your vehicle and your trailer.
Cross the safety chains under
the tongue of the trailer so that the tongue will
not drop to
the road if it becomes separated from the hitch. Instructions
about safety chains may be provided by the hitch manufacturer or by the
trailer manufacturer. Follow
the manufacturer’s recommendation for
attaching safety chains. Always leave just enough slack
so you can turn with
your rig. And, never allow safety chains to drag on the ground.
Trailer Brakes
If your trailer weighs more than 1,000 pounds (450 kg) loaded, then it needs
its own brakes
- and they must be adequate. Be sure to read and follow the
instructions for
the trailer brakes so you’ll be able to install, adjust and
maintain them properly.
Your trailer brake system can tap
into your vehicle’s hydraulic brake system,
but consider
the following:
0 Will the trailer brake system use more than 0.02 cubic inch (0.3 cc) of
fluid from your vehicle’s master cylinder? If it will, don’t tap into your
vehicle’s brake system. Both braking systems won’t work well, and
you
could even lose your brakes altogether.
0 Will the trailer brake parts take 3,000 psi (20 650 kPa) of pressure? If
not, the trailer brake system must not be used with your vehicle.
If everything checks out this far, make the brake tap at the port on
the
master cylinder that sends the fluid to the rear brakes. But don’t use copper
tubing for this.
if you do, it will bend and finally break off. Use steel brake
tubing.
Driving with a Trailer
Towing a trailer requires a certain amount of experience. Before setting out
for the open road, you’ll want to get to know your rig. Acquaint yourself
with the feel of handling and braking with the added weight
of the trailer.
And always keep
in mind that the vehicle you are driving is now a good
deal longer and
not nearly so responsive as your vehicle is by itself.
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Before you start, check the trailer hitch and platform, safety chains,
electrical connector, lights, tires and mirror adjustment. If the trailer has
electric brakes, start your
vehicle and trailer moving and then apply the
trailer brake controller by hand to be sure the brakes are working. This lets
you check your electrical connection at
the same time.
During your trip, check occasionally to be sure that the load is secure, and
that the lights and any trailer brakes are still working.
Following Distance
Stay at least twice as far behind the vehicle ahead as you would when
driving your vehicle without a trailer. This can help
you avoid situations that
require heavy braking and sudden turns.
Passing
You’ll need more passing distance up ahead when you’re towing a trailer.
And, because you’re a good deal longer, you’ll need to
go much farther
beyond the passed vehicle before
you can return to your lane.
Backing Up
Hold the bottom of the steering wheel with one hand. Then, to move the
trailer to the left, just move that hand to the
left. To move the trailer to the
right, move your hand to
the right. Always back up slowly and, if possible?
have someone guide you.
Making Turns
When you’re turning with a trailer, make wider turns than normal. Do this
so your trailer won’t strike soft shoulders, curbs, road signs, trees, or other
objects. Avoid jerky or sudden maneuvers. Signal well in advance.
Turn Signals When Towing a Trailer
When you tow a trailer, your vehicle has to have a different turn signal
flasher and extra wiring. The green arrows
on your instrument panel will
flash whenever you signal a turn or lane change. Properly hooked up, the
trailer lights will also flash, telling other drivers you’re about to turn,
change lanes or stop.
When towing a trailer, the green arrows on your instrument panel will flash
for turns even if the bulbs
on the trailer are burned out. Thus, you may think
drivers behind you are seeing your signal when
they are not. It’s important
to check occasionally
to be sure the trailer bulbs are still working.
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Driving On Grades
Reduce speed and shift to a lower gear before you start down a long or
steep downgrade.
If you don’t shift down, you might have to use your
brakes
so much that they would get hot and no longer work well.
On a long uphill grade, shift down and reduce your speed to around
45 mph
(70 km/h) to reduce the possibility of engine and transmission overheating.
When towing at high altitude with steep uphill grades,you need to consider
the following information. The lower atmospheric pressure at high altitude
allows your vehicles engine coolant to boil at a lower temperature than at
normal altitudes.
If you immediately turn your engine off after towing at high altitude with
steep uphill grades, your vehicle may show signs similar
to engine
overheating.
To avoid this, let your vehicle operate in a parked position with
the transmission in
“N” (Neutral) for a few minutes before you turn off the
engine. If you do get the overheat warning, see “Engine Overheating” in
the Index.
If you have an automatic transmission, you should use
“D” (or, as you need
to, a lower gear) when towing a trailer. Operating your vehicle in
“D” when
towing a trailer will minimize heat buildup and extend the life
of your
transmission.
If you have a manual transmission and
you are towing a trailer, it’s better
not to use fifth gear. Just drive in fourth gear (or, as you need to, a lower
gear).
Parking on Hills
You really should not park your vehicle, with a trailer attached, on a hill. If
something goes wrong, your rig could start
to move. People can be injured,
and both your vehicle and the trailer can be damaged.
But if you ever have to park your rig on a hill, here’s how
to do it:
1.
2.
3.
4.
5.
6.
Apply your regular brakes, but don’t shift into “P’ (Park) yet, or in gear
for a manual transmission.
Have someone place chocks under the trailer wheels.
When the wheel chocks are in place, release the regular brakes until the
chocks absorb
the load.
Re-apply the regular brakes. Then apply your parking brake, and then
shift to
“P7, (Park), or “R” (Reverse) for a manual transmission.
If
you have a four-wheel-drive vehicle, be sure the transfer case is in a
drive gear-not in
“N7 (Neutral).
Release
the regular brakes.
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A CAUTION:
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.
If’ you have 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, use the
steps that follow.
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).
If you are parking on a hill, or if you’re pulling a trailer, also see
“Parking
On Hills” in the Index.
When You Are Ready to Leave After Parking on a Hill
1. Apply your regular brakes and hold the pedal down while you:
Start your engine;
Shift into a gear; and
0 Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
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
fluid (don’t overfill), engine oil,
axle lubricant, belts, cooling system, and brake adjustment. 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 Light Wiring
See “Trailer Wiring Harness” in the Index.
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To Jump Start Your Vehicle
1. Check the other vehicle. It must have a 12-volt battery with a negative
ground system.
I NOTICE:
If the other system isn’t a 12-volt system with a negative
ground, both vehicles can be damaged.
If you have a diesel engine vehicle with two batteries (or more), you
should know before
you begin that, especially in cold weather, you may
not be able to get enough power from
a single battery in another
vehicle to start your diesel engine.
If your vehicle
has more than one battery, use the battery that’s on the
passenger side
of the vehicle - this will reduce electrical resistance.
sure the vehicle’s aren’t touching each other.
If they are, it could cause
a ground connection you don’t want. You wouldn’t be able to start your
vehicle, and the bad grounding could damage
the electrical systems.
You could be injured
if the vehicles roll. Set the parking brake firmly
on each vehicle. Put an automatic transmission
in “P” (Park) or a
manual transmission in “N” (Neutral). If you have a four-wheel-drive
vehicle, be sure
the transfer case is not in “N” (Neutral).
2. Get the vehicles
close enough
so the jumper cables can reach, but be
3. Turn off the ignition on both vehicles. Turn off all lights that aren’t
needed, and radios. This will avoid sparks and help save both batteries.
And it could save
your radio!
NOTICE:
If you leave your radio on, it could be badly damaged. The
repairs wouldn’t be covered by your warranty.
4. Open the hoods and locate the batteries. Find the positive (+) and
negative
(-) terminals on each battery.
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When you call, tell the towing service:
That your vehicle has rear-wheel drive, or that it has the four-wheel
drive option.
The make, model, and year of your vehicle.
Whether you can move the shift lever for the transmission and transfer
case,
if you have one.
If there was an accident, what was damaged.
1
When your vehicle is being towed, have the ignition key off. The steering
wheel should be clamped
in a straight-ahead position, with a clamping
device designed for towing service.
Do not use the vehicle’s steering
column lock for this. The transmission and transfer case,
if you have one,
should be in Neutral and
the parking brake released.
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..I . ... . ;. ..
Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When the clutch is engaged,
the fan spins faster
to provide more air to cool the engine. In most every day
driving conditions
the fan is spinning slower and clutch is not fully engaged.
This improves fuel economy and reduces fan noise. Under heavy vehicle
loading, trailer towing and/or high outside temperatures, the fan speed
increases as
the clutch more fully engages. So you may hear an increase in
fan noise. This is normal and should not be mistaken as the transmission
slipping or making extra shifts. It is merely the cooling system functioning
properly. The fan will slow down when additional cooling is not required
and
the clutch partially disengages.
You may also hear
this fan noise when you start the engine. It will go away
as
the fan clutch partially disengages.
If a Tire Goes Flat
It’s UfluSual for a tire to “blow out” while you’re driving, especially if you
maintain your tires properly. If air goes out of a tire, it’s much more likely to
leak
out slowly. But if you should ever have a “blowout,’’ here are a few tips
about what
to expect and what to do:
If a front tire fails, the flat tire will create a drag that pulls the vehicle
toward that side. Take your foot off
the accelerator pedal and grip the
steering wheel firmly. Steer to maintain lane position, then gently brake to a
stop well
out of the traffic lane.
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