brake GMC SIERRA 1994 Workshop Manual

If the light comes on at any other time, use this chart.
“Water in Fuel” Light Chart
Problem
Light comes on intermittently.
Light stays on:
1. At temperatures above
freezing.
2. At temperatures below
freezing.
Recommended Action
Drain water from fuel filter.
Drain fuel filter immediately. If no
water
can be drained and light stays
on, see your dealer for assistance.
Drain fuel filter immediately. If no
water can be drained
- water may
be frozen. Open the air bleed valve
to check
for fuel pressure. If no fuel
pressure is present, replace the
fuel
filter.
3. Immediately after refueling - Fuel tank purging required. See
large amount of water possibly your dealer for assistance.
pumped into fuel tank.
Hesitation or “flat” performance at high speed or during hard acceleration
may be an indication of premature fuel filter plugging due
to dirty or
contaminated fuel, The filter element may need to be changed
if this
happens. See your dealer for assistance.
NOTICE:
If you drive when this warning light is on, you can damage y\
our
fuel injection system and your engine. If the light comes on right
after you refuel,
it means water was pumped into your fuel tank.
Turn off your engine immediately. Then, have the water drained \
at once.
To drain water:
1. Stop and park the vehicle in a safe place. Turn off the engine and apply
the parking brake.
2. Remove the fuel tank cap.
3. Place a fuel-resistant container under the filter drain hose.
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A CAUTION:
Diesel fuel is flammable. It could start a fire if it gets on hot
engine parts. You could be burned. Don’t let too much fuel flow
from the air bleed valve, and wipe up any spilled fuel with
a
cloth.
3. Close the air bleed valve.
4. Turn the ignition key to “Start” for 10 to 15 seconds at a time until your
engine starts.
Fuel Filter Replacement (Diesel Engines)
If you want to change the fuel filter yourself, here’s how to do it:
Before you remove the filter, drain any water that may have collected in the
fuel filter or filter head. See “Water in Fuel” earlier in this section to find
out how to remove water from the fuel system.
Then, drain
fuel from the filter by opening the air bleed valve and the water
drain valve. This prevents the fuel from spilling as
you replace the filter.
Drain the fuel into
a fuel-resistant container and dispose of it properly.
A CAUTION:
Diesel fuel is flammable. It could start a fire if something ignites
it, and you could be burned. Don’t let it get on hot engine parts,
and keep matches or other ignition sources away.
I. Turn off the engine and apply the parking brake.
2. Take off the fuel tank cap. This releases vacuum in the tank.
3. The filter is located at the rear of the intake manifold.
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Things that burn can get on hot engine parts and start a fire.
These include liquids like gasoline or diesel fuel, oil, coolant,
brake fluid, windshield washer and other fluids, and plastic or
rubber. You or others could be burned. Be careful not to drop or
I spill things that will burn onto a hot engine.
Before closing the hood, be sure all filler caps are on properly. Pull down
the hood and close it firmly.
Cleaning Your Diesel Engine
NOTICE:
If you spray or pour water or any other liquid on your engine
when it is warm or hot, or when it is running,
you could cause
serious damage to it.
If you ever clean the engine, clean it only
when it is cold.
Noise Control System
The following information relates to compliance with Federal noise
emission standards for vehicles
with a Gross Vehicle Weight Rating
(GVWR) of more than
10,000 pounds (4 536 kilograms). The Maintenance
Schedule booklet provides information on maintaining the noise control
system to minimize degradation
of the noise emission control system during
the life of your vehicle. The noise control system warranty
is given in your
Warranty hooklet.
These standards apply only to vehicles sold
in the United States.
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I NOTICE:
Too much or too little fluid can damage your transmission. Too
much can mean that some of the fluid could come out and fall on
hot engine parts or exhaust system, starting
a fire. Be sure to get
an accurate reading
if you check your transmission fluid.
Wait at least 30 minutes before checking the transmission fluid level if you
have been driving:
0 When outside temperatures are above 90°F (32°C).
At high speed for quite a while.
0 In heavy traffic - especially in hot weather.
While pulling a trailer.
IU get the right reading, the fluid should be at normal operating
temperature, which
is 180°F to 200°F (82°C to 93°C).
To check trunsmissioltfluid hot: Get the vehicle warmed up by driving
about
15 miles (24 km) when outside temperatures are above 50°F (1 0°C).
If it’s colder than
50°F (lO”C), drive the vehicle in “D” (3rd Gear) until the
engine temperature gage moves and then remains steady for ten minutes.
Then follow
the hot check procedures.
To check trmzsnzissiorz jZuid cold: A cold check is made after the vehicle has
been sitting for eight hours
or more with the engine off and is used only as a
reference. Let
the engine run at idle for five minutes if outside temperatures
are
50°F ( 10°C) or more. If it’s colder than 50°F (lO”C), you may have to
idle the engine longer. Should the fluid level be low during a cold check,
you must perform a hot check before adding fluid. This will give you a
more accurate reading of the fluid level.
To check the fluid hot or cold
Park your vehicle on a level place.
With the parking brake applied, place the shift lever in “P” (Park).
With your foot on the brake pedal, move the shift lever through each
gear range, pausing for about three seconds
in each range. Then,
position
the shift lever in “P’ (Park).
Let the engine run at idle for three minutes or more.
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When the engine
compartment is
hot, the level
should be at the
FULL mark.
When the engine
compartment
is
cool, the level
should be at the
FULL COLD
mark.
What to Add
Refer to the Maintenance Schedule to determine what kind of fluid to use.
See “Recommended Fluids and Lubricants”
in the Index.
NOTICE:
When adding power steering fluid or making a complete fluid
change, always use the proper fluid. Failure
to use the proper
fluid can cause leaks and damage hoses and seals.
Hydro-Boost Brake System (Hydraulic Pump)
The power steering pump is also used as the Hyrdo-boost pump. Refer to
“Power Steering System”
in this section when checking fluid level or
adding tluid.
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Brakes
Brake Master Cylinder
Your brake master
cylinder is here. It is
filled with
DOT-3
brake fluid.
There are only two reasons
why the brake fluid level in your master cylinder
might
go down, The first is that the brake fluid goes down to an acceptable
level during normal brake lining wear. When new linings are put in, the
fluid level goes back up. The other reason is that fluid is leaking
out of the
brake system.
If it is, you should have your brake system fixed, since a leak
means that sooner or later your brakes
won’t work well, or won’t work at
all.
So, it isn’t a good idea to “top off’ your brake fluid. Adding brake fluid
won’t correct a leak.
If you add fluid when your linings are worn, then
you’ll have
too much fluid when you get new brake linings. You should add
(or remove) brake fluid,
as necessary, only when work is done on the brake
hydraulic system.
Refer
to the Maintenance Schedule to determine when to check your brake
fluid. See “Periodic Maintenance Inspections”
in the Index.
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To Check Brake Fluid
You can check the
brake fluid without
taking off the cap. Just
look at the windows
on the brake fluid
reservoir. The fluid
levels should be above
“MIN.” If they aren’t,
have your brake system checked to see
if there is a leak.
After work
is done on the brake hydraulic system, make sure the levels are
above
“MIN” and below the top of each window.
What to Add
When you do need brake fluid, use only DOT-3 brake fluid - such as
Delco Supreme
ll@ (GM Part No.1052535). Use new brake fluid from a
sealed container only, and always clean the brake fluid reservo\
ir cap before
removing it.
NOTICE:
Don’t let someone put in the wrong kind of fluid. For
example, just
a few drops of mineral-based oil, such as engine
oil, in your brake system can damage brake system parts so
badly that they’ll have to be replaced.
Brake fluid can damage paint, so be careful not to spill brake
fluid
on your vehicle. If you do, wash it off immediately. See
“Appearance Care” in the Index.
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Brake Wear
Your vehicle has front disc brakes and rear drum brakes. If you have a
C 3500 HD model, it has four-wheel disc brakes.
Disc brake pads have built-in wear indicators that make
a high-pitched
warning sound when the brake pads are worn and new pads are needed. The
sound may come and go or be heard
all the time your vehicle is moving
(except when you are pushing on the brake pedal firmly).
The brake wear warning sound means that sooner or later your
brakes won’t work well. That could lead to an accident.
When
you hear the brake wear warning sound, have your vehicle
serviced.
NOTICE:
Continuing to drive with worn-out brake pads could result in
costly brake repair.
Some driving conditions or climates may cause a brake squeal when the
brakes are first applied or lightly applied. This does not mean something is
wrong with your brakes.
If
you have rear drum brakes, they don’t have wear indicators, but if you
ever hear a rear brake rubbing noise, have
the rear brake linings inspected.
Also, the rear brake drums should be removed and inspected each time the
tires are removed for rotation or changing. When you have
the front brakes
replaced, have the rear brakes inspected, too.
Brake linings should always be replaced
as complete axle sets.
Brake Pedal Travel
See your dealer if the brake pedal does not return to normal height, or if
there is a rapid increase in pedal travel. This could be a sign of brake
trouble.
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Brake Adjustment
Every time you make a brake stop, your disc brakes adjust for wear.
If your brake pedal goes down farther than normal, your rear drum brakes
may need adjustment. Adjust them by backing up and firmly applying
the
brakes a few times.
Replacing Brake System Parts
The braking system on a modern vehicle is complex. Its many parts have to
be of top quality and work well together if the vehicle is to have really good
braking. Vehicles we design and test have top-quality
GM brake parts in
them, as your vehicle does when it is new. When you replace parts of your
braking system
- for example, when your brake linings wear down and
you have to have new ones put
in - be sure you get new genuine GM
replacement parts. If you don’t, your brakes may no longer work properly.
For example,
if someone puts in brake linings that are wrong for your
vehicle, the balance between your front and rear brakes can change, for
the
worse. The braking performance you’ve come to expect can change in many
other ways if someone puts in the wrong replacement brake parts.
Other Maintenance Hems
Front Suspension and Steering Linkage
Your maintenance schedule will tell you how often to lubricate the fittings.
See “Recommended Fluids and Lubricants”
in the Index for the proper
lubricant to use.
Front Wheel Bearings
Your vehicle has front wheel bearings that must be cleaned and repacked.
Your maintenance schedule
will tell you how often this must be done.
Front Shock Absorbers
The front shock absorbers of your vehicle do many things. They help the
vehicle ride smoothly and also control
the travel of the suspension system.
When the shock absorbers are serviced, any replacement shock absorbers
must be
the same as the original equipment shock absorbers in both
extended length and strength.
NOTICE:
If you use shock absorbers that are not the same as the original
shock absorbers, the shock absorbers
or suspension system
could be damaged.
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Trailer Wiring Harness
The optional seven-wire trailer wiring harness is protected by an in-line
fuse
in the battery feed wire. This fuse is near the junction block. See
“Trailer Wiring Harness”
in the Index for more information.
Fuse Block
The fuse block is
behind an access door
at the bottom of the
instrument panel,
next
to the parking brake
release lever.
To remove fuses if you don’t have one, hold the end of the fuse between
your thumb and index finger and pull straight out.
Be, sure to use the correct fuse.
If you ever have a problem on the road and
don’t have a spare fuse, you can “borrow” one of the correct value. Just pick
some feature
of your vehicle that you can get along without-like the radio
or cigarette lighter--and use
its fuse, if it is of the value you need. Replace
it as soon as you can. See “Fuses and Circuit Breakers“ in the Index for
more information.
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