brake GMC SIERRA 1997 Service Manual

Turn Signals When Towing a Trailer
The arrows on your instrument panel will flash
whenever you signal a turn or lane change. Properly
hooked up, the trailer lamps will also flash, telling other
drivers you’re about to turn, change lanes or stop.
When towing a trailer, the 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.
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. If you have an automatic transmission, you can tow
in
AUTOMATIC OVERDRIVE (a). You
may want to
shift the transmission to THIRD
(3) or, if necessary, a
lower gear selection if the transmission shifts too often
(e.g., under heavy loads and/or hilly conditions).
If you have a manual transmission and you are towing a
trailer, it’s better not to use
FIFTH (5) gear. Just drive in
FOURTH
(4) gear (or, as you need to, a lower gear).
When towing at high altitude on steep uphill grades,
consider the following: Engine coolant will boil at a
lower temperature than at normal altitudes. If
you turn
your engine off immediately after towing at high altitude
on steep uphill grades, your vehicle may show signs
similar to engine overheating.
To avoid this, let the
engine run while parked (preferably on level ground)
with the automatic transmission in
PARK (P) (or the
manual transmission out of gear and the parking brake
applied) for a few minutes before turning the engine
off.
If you do get the overheat warning, see “Engine
Overheating”
in the Index.
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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. Apply your regular brakes, but don't shift into
PARK
(P) yet for an automatic transmission, or into
gear for a manual transmission.
2. Have someone place chocks under the trailer wheels.
3. When the wheel chocks are in place, release the
regular brakes until the chocks absorb
the load.
4. Reapply the regular brakes. Then apply your parking
brake and shift
into PARK (P) for an automatic
transmission, or
REVERSE (R) for a
manual transmission.
5. If you have a four-wheel-drive vehicle, be sure
the transfer case is
in a drive gear and not in
NEUTRAL
(N).
6. Release the regular brakes.
c
It can be dangerous to get out of your vehicle if
the shift lever
is not fully in PARK (P) 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 NEUTRAL (N), your vehicle will be free
to roll, even if your shift lever
is in PARK (P). So,
be sure the transfer case is in a drive gear -- not
in
NEUTRAL (N).
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When You Are Ready to Leave After
Parkine
on a Hill
1. Apply your regular brakes and hold the pedal down
while you:
Start your engine;
Shift into a gear; and
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 transmission fluid (don’t
overfill), engine oil, axle lubricant, belt, 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.
Trailer Wiring Harness
A seven-wire harness is stored under the rear end of
your vehicle, between
the frame rails. An electrical
connector will need to be installed at the trailer end of
the harness, by a qualified electrical technician. For
additional trailer wiring and towing information please
consult your
GM dealer. Securely attach the harness to
the trailer, then tape or strap
it to your vehicle’s frame
rail. Be sure you leave it loose enough
so the wiring
won’t bind or break when turning with the trailer, but
not
so loose that it drags on the ground. Store the
harness in its original position. Wrap the harness
together and tie
it neatly so it won’t be damaged. If you
tow
a trailer, your Center High-Mounted Stoplamp
(CHMSL) may not be properly visible from behind.
You
should select a trailer with a CHMSL on it or, if one is
not available, have one installed. See your
GM dealer
about how to connect your vehicle’s wiring
to a
trailer CHMSL.
Check periodically to see that all hitch nuts and bolts
are tight.
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Power Winches
If you wish to use a power winch on your vehicle, only
use it when your vehicle is stationary or anchored.
I NOTICE:
Using a power winch with the transmission in
gear may damage the transmission. When
operating a power winch, always leave the
transmission in NEUTRAL
(N).
Use the regular brakes, set the parking brake, or block
the wheels
to keep your vehicle from rolling.
Power Take-Off (PTO) (Manual Tkansmission)
NOTICE:
If you have a PTO that will exceed 35 hp installed
on your vehicle, it could damage the transfer case
or transmission. When having
a PTO installed
on
your vehicle, make sure that it will not exceed
35 hp. Before using
a PTO, refer to the manufacturer’s
or
installer’s instructions.
I NOTICE:
Using a PTO while operating in one place before
the vehicle has reached normal operating
temperature can damage the transfer case or
transmission. If you will be using the
PTO while
operating in one place, drive and warm up the
vehicle before using the
PTO.
To engage a PTO:
1. Hold the clutch pedal down.
2. Set the parking brake.
3. Shift the transmission into NEUTRAL (N).
4. Engage the PTO.
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NOTICE:
Using a PTO for more than four hours without
driving your vehicle can damage the transfer case
or transmission. If using a
PTO for more than
four hours without driving your vehicle, drive your vehicle for a while
to allow the transfer case
and transmission
to cool.
If you are going to drive the vehicle, shift the
transfer case into the range you want (if
you have
four-wheel drive). Then shift the transmission into
the' gear you want, apply the regular brakes and
release the parking brake.
5. Release the clutch (and the regular brakes) as you
normally would. When you release the clutch, the
PTO will start.
To engage a PTO while the vehicle is moving:
1. Hold the clutch pedal down.
2. Shift the transmission into NEUTRAL (N).
3. Engage the PTO.
4. Shift the transmission into the gear you want.
5. Release the clutch as you normally would. When you
release the clutch, the PTO will start.
Using a Transfer Case Mounted Power
Take-Off (Manual Transmission)
1.
2.
3.
4.
5.
6.
Hold the clutch pedal down.
Set the parking brake.
Shift the transfer case into NEUTRAL
(N).
If the vehicle will remain in the same place, shift the
transmission into the highest gear.
Engage
the PTO.
If you are going to drive the vehicle, shift the
transmission into the gear you want. Then shift the
transfer case into
the range you want, apply the
regular brakes and release
the parking brake.
Release the clutch (and the regular brakes) as you
normally would. When you release
the clutch, the
PTO will start.
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Using a Transfer Case Mounted Power
Take-Off (Automatic Transmission)
1. Set the parking brake.
2. Turn the ignition off.
3. Shift the transfer case into NEUTRAL (N).
4. Shift the transmission into NEUTRAL (N).
5. Engage the PTO.
If you are going to drive the vehicle, shift the
transfer case into the range you want. Turn the
ignition to START. Then apply the regular brakes
and release the parking brake.
6. Shift the transmission to THIRD (3) to start the PTO.
7. Release the regular brakes to drive the vehicle.
Disengaging a Power Take-OFF
1. Turn the ignition off.
2. Put the transmission in PARK (P).
3. Release the PTO
4. Restart the engine.
Step-Bumper Pad
If your vehicle has a rear step bumper, it may be equipped
with a rear step pad at the center of the bumper.
If you will be using the
bumper to tow a trailer, you
must remove the center
cutout circle to install
the trailer ball. You must
also remove both outer
cutouts to attach the trailer
safety chains.
To remove the pad, lift the
edge
of the pad from the
rear of the bumper and
the pad releases from the
bumper holes, lift the
pad
off.
swing it forward. When
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2. Get the vehicles close enough so the jumper cables
can reach, but be
sure the vehicles 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.
To avoid the possibility of the vehicles rolling, set the
parking brake
fmly on both vehicles involved in the
jump stat procedure. Put an automatic transmission in
PARK (P) or a manual transmission in NEUTRAL (N).
If you have a four-wheel-drive vehicle, be sure the
transfer case is not
in NEUTRAL (N).
3. Turn off the ignition on both vehicles. Unplug
unnecessary accessories plugged into the cigarette
lighter or accessory power outlets. Turn
off all lamps
that aren’t needed as well
as radios. This will avoid
sparks and help save both batteries.
In addition, it
could save your radio!
I 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.
If your vehicle has air conditioning, the auxiliary
electric fan under the hood can start
up even
when the engine is not running and can injure
you. Keep hands, clothing and tools away
from
any underhood electric fan.
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Front Towing 4. Put an automatic transmission in PARK (P) or
manual transmission in FIRST
(1).
5. Put the transfer case in NEUTRAL (N).
6. When the vehicle is hooked up, release the
7. Maximum speed 55 mph (88 kmh), distance
If your vehicle is a two-wheel drive or a four-wheel
drive with an electric shift transfer case,
use the
following directions: parking brake.
unlimited.
1.
2.
3.
If your vehicle is four-wheel drive with a manual transfer case, use the following directions:
1. Turn the ignition key to the OFF position.
2. Engage the parking brake.
3. Clamp the steering wheel in a straight-ahead position
with a clamping device designed for towing service.
(Do not use the vehicle’s steering column lock for this.)
4.
5.
6.
7.
Turn the ignition key to the OFF position.
Engage the parking brake.
Clamp the steering wheel in a straight-ahead
position with
a clamping device designed for
towing service.
(Do not use the vehicle’s steering
column lock
for this.)
Put an automatic transmission
in NEUTRAL (N) or
manual transmission in FIRST (1).
Put the transfer case
in 2HIGH (2HI).
When
the vehicle is hooked up, release the
parking brake.
Maximum speed
35 mph (55 km/h), maximum
distance
50 miles (80 km).
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Engine Fan Noise
Your vehicle has a clutched engine cooling fan. When
the clutch is engaged, the fan spi.ns faster to provide
more air
to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the 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 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 unusual 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, and then gently brake to
a stop well out of the traffic lane.
A rear blowout, particularly on a curve, acts much like a
skid and may require the same correction you’d use in
a skid. In any rear blowout, remove your foot from
the accelerator pedal. Get the vehicle under control by
steering the way you want the vehicle to go. It may be
very bumpy and noisy, but
you can still steer. Gently
brake
to a stop -- well off the road if possible.
If a tire goes flat, the next part shows how to
use your
jacking equipment
to change a flat tire safely.
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Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your hazard
warning flashers.
I A CAUTION:
Changing a tire can cause an injury. The vehicle
can slip
off the jack and roll over you or other
people. You and they could be badly injured.
Find a level place
to change your tire. To help
prevent the vehicle from moving:
1. Set the parking brake firmly.
2. Put an automatic transmission shift
lever in
PARK (P) or shift a manual
transmission to
FIRST (1) or
REVERSE (R).
3. If you have a four-wheel-drive vehicle,
be
sure the transfer case is in a drive
gear
-- not in NEUTRAL (N).
4. Turn off the engine.
CAUTION: (Continued)
To be even more certain the vehicle won’t move,
you can put blocks at the front and rear of the
tire farthest away from the one being changed.
That would be the tire on the other side
of the
vehicle, at the opposite end.
The following steps will tell
you how to use the jack and
change
a tire.
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