brake GMC SIERRA 1993 Workshop Manual

Your Driving and the Road
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 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
45 mph (70
kmlh) or less to reduce the possibility of engine and transmission overheating.
IT you have an automatic transmission, you should use D (or, as you need to,
a lower gear) when towing a trailer. Operating your vehicle i\
n
D when towing
a trailer will minimize heat buildup and extend the life of your transmission.
Or, if you have a manual transmission with fifth gear 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. Apply your regular brakes, but don’t shift into P (Park) yet, or into gear
2. Have someone place chocks under the trailer wheels.
for a manual transmission.
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 \
then
5. If you have a four-wheel-drive vehicle, be sure the transfer case is in a
6. Release the regular brakes.
shift
to
P (Park), or R (Reverse) for a manual transmission.
drive gear-not in
N (Neutral).
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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 suddenl\
y.
You
or others could be injured. To be sure your vehicle won’t move,
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 Parklng 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 To wing
Your vehicle will need service more often when you’re pulling a trailer. See
the Maintenance Schedule for more on this. Things that are esp\
ecially
important in trailer operation are automatic transmission fluid (don’t overfill),
engine oil, axle lubricant, belts, cooling system, and brake ad\
justment. 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.
mailer Wiring Harness
See “Trailer Wiring Harness’’ in the Index.
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Your Driving and the Road
Power Winches
i !
If you wish to use a power winch on your vehicle, only use it \
when your
vehicle is stationary or anchored.
i
NOTICE
Use the regular brakes, set the parking brake or block the wh\
eels to keep
your vehicle from rolling.
Power rake-off (PTO)
Before using a power take-off, refer to the manufacturer’s or installer’s
instructions.
To engage a power take-off:
1. Set ths parking brake.
2. Shift the transmission into N (Neutral).
3. Hold the clutch pedal down and engage the power take-off.
*
If you are going to drive the vehicle, shift the transmission int\
o the gear
you want. Then shift the transfer case into the range you wan\
t
(if you
have four-wheel-drive), apply the regular brakes and release th\
e parking
brake.
When you release the clutch, the power take-off will start.
4. Release the clutch (and the regular brakes) as you normally \
would.
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Using a Transfer Case Mounted Power Take-Off (Manual
Transmission)
1. Set the parking brake.
2. Shift the transfer case into N (Neutral).
3. Hold the clutch pedal down. If the vehicle will remain in the same place,
4. Engage the power take-off.
shift the transmission into the highest
gear.
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 wan\
t, apply
the regular brakes and release the parking brake.
5 Release the clutch (and the regular brakes) as you normally \
would.
Using a Transfer Case Mounted Power Take-Off (Automatic
Transmission)
When you release the clutch, the power take-off will start.
1 I 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 power take-off.
6. Release the regular brakes to drive the vehicle.
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Pmbkms on the Road
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 closest
to the starter-this will reduce electrical resistance.
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 syst\
ems.
You could be injured
if the vehicles roll. Set the parking brake firmly
manual transmission in
N (Neutral).
If you have a four-wheel-drive vehicle, be sure the transfer c\
ase is
not in
N (Neutral).
1 on each vehicle. Put an automatic transmission in P (Park) or a
3. Turn off the ignition on both vehicles. Turn off all lights that aren’t need-
ed, and radios. This will avoid sparks and help save both bat\
teries. And
it could save your radio!
ou leave your radio on, it could be badly damaged. The repairs
r.,Jldn’t be covered by your warranty. I
4. Open the hoods and locate the batteries.
Find the positive
(t) and negative (-) terminals on each battery.
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Problenrs on the Road
Towing Your Vehicle
Try to have a GM dealer or a professional towing service tow your vehicle.
They can provide the right equipment and know how to tow it without dam-
age.
If your vehicle has been changed since it was factory-new, by adding things
like fog lamps, aero skirting, or special tires and wheels, th\
ese things could
be damaged during towing.
Before you do anything, turn on the hazard warning flashers.
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.
I A To help avoid injury to you or others:
Never let passengers ride in a vehicle that is being towed.
Never tow faster than safe or posted speeds.
Never tow with damaged parts not fully secured.
Never get under your vehicle after it has been lifted by the tow
truck.
Always use separate safety chains on each side when towing a
vehicle.
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 Neu-
tral and the parking brake released.
If you have a two-wheel drive vehicle, don’t have your vehicle \
towed on the
rear wheels, unless you must. If the vehicle must be towed on\
the rear
wheels, don’t go more than
35 mph (56 km/h) or farther than 50 miles (80
krn) or your transmission will be damaged. If these limits must be exceeded,
then the rear drive wheels have to be supported on a dolly.
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Engine Fan Noise
This 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 clutch is not engaged. This improves fue\
l economy and
reduces fan noise. Under heavy vehicle loading, trailer towing andlor high
outside temperatures, the fan speed increases when the clutch e\
ngages.
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 disengages.
If a Tire Goes Fiat
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, 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 your tire goes flat, the next part shows how to use your jacking equipment
to change a flat tire safely.
Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage by driv\
ing slowly to a
level place. Turn on your hazard warning flashers.
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Service & Appearance Care
Engine Coolant ........................................................................\
........................ 6-42
Power Steering Fluid
........................................................................\
............... 6-46
Windshield Washer Fluid
........................................................................\
......... 6-48
Brake Master Cylinder
........................................................................\
............. 6-49
Replacing Brake System Parts
........................................................................\
.. 6-50
Other Maintenance Items ........................................................................\
........... 6-51
Lubrication
........................................................................\
.................................... 6-52
Electrical System
........................................................................\
......................... 6-54
Battery
........................................................................\
...................................... 6-54
Fuses and Circuit Breakers
........................................................................\
.... 6-64
Bulb Replacement
........................................................................\
.................... 6-54
Exhaust System
........................................................................\
........................... 6-65
Loading Your Vehicle
........................................................................\
.................. 6-67
Tires
........................................................................\
.............................................. 6-72
Inflation-Tire Pressure
........................................................................\
........... 6-73
Tire Inspection and Rotation
........................................................................\
.. 6-78
When It's Time for New Tires
........................................................................\
6-80
Buying New Tires
........................................................................\
.................... 6-81
Wheel Alignment and Tire Balance
............................................................... 6-82
Wheel Replacement
........................................................................\
................. 6-83
Tire Chains
........................................................................\
............................... 6-84
Appearance Care
........................................................................\
........................ 6-84
Cleaning the Inside Of Your Vehicle
............................................................. 6-85
Cleaning the Outside Of Your Vehicle
.......................................................... 6-88
Appearance Care Materials
.r.ikl...rr.r.n.....lr. ........ ... .. 6-91
Vehicle Identification Number
........................................................................\
..... 6-92
Service Parts Identification Label
...................................................................... 6-94
Specification Charts
....++t....,.,.*,..-".,,. .............. , ........... .................... 6-95
Uniform Tire Quality Grading
........................................................................\
.. 6-81
..................................................
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2. Unplug the Shut-Off solenoid wire from the fuel pump to prevent the
engine from starting.
3. With the air bleed valve open, turn your ignition key to Start for 10 to
15 seconds to crank (but not start) your engine. Keep doing this until
you can just see some clear fuel at the air bleed valve.
I A Diesel fuel is flammable. It could start a fire if it gets on hot engine
b parts. You could be burned. Don’t let too much fuel flow from the air
bleed valve or screw, and wipe up any spilled fuel with a cloth.
4. Close the air bleed valve, or replace the screw and reconnect \
the
Shut-Off solenoid wire.
5. Turn the ignition key to Start for 10 to 15 seconds at a time until your
engine starts.
Fuel Filter Replacement (6.5L Diesel Engines)
If you want to change the fuel filter yourself, here’s how \
to do it:
1 CAUTION
A Diesel fuel is flammable. It could start a fire if something ignites it,
-L and you could be burned. Don’t let it get on hot .engine parts, and
I keep matches or other ignition sources away.
1. Turn off your engine and set your parking brake.
2. Take off the fuel tank cap. This releases pressure in the tank.
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Service & Appearance Care
To remove the filter:
1. Turn off your engine and set your parking brake.
2. Take off the fuel tank cap. This releases pressure in the tank.
1.. ,
K2669
3. The filter is behind the air cleaner on the intake manifold. Using a
4. If there is any dirt on the fuel port seal of the filter adapter, clean \
it off.
5. Snap the new filter into position with the bail wires.
screwdriver, separate both bail wires. Take out the filter.
K2671
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