brake GMC ENVOY 1998 Workshop Manual

Checking Brake Fluid What to Add
You can check the brake
fluid without taking off
the cap.
Just look at the brake fluid reservoir. The fluid level
should be above
MIN. If it isn’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 level is above the MTN but not over
the
MAX mark or the top of the window on the side
of the reservoir. When
you do need brake fluid, use only
DOT-3
brake fluid -- such as Delco Supreme 11 @ (GM Part
No.
12377967). Use new brake fluid from a sealed
container only.
Always clean the brake fluid reservoir cap and the
area
around the cap before removing it. This will help keep
dirt from entering the reservoir.
A CAUTION:
With the wrong kind of fluid in your brake
system, your brakes may not work well, or they
may not even work at
all. This could cause a
crash. Always use the proper brake fluid.
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NOTICE:
0 Using the wrong fluid can badly damage
brake system parts. 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. Don’t let someone put in the
wrong kind of fluid.
If you spill brake fluid on your vehicle’s
painted surfaces, the paint finish can be
damaged. Be careful not to spill brake fluid
on your vehicle.
If you do, wash it off
immediately. See “Appearance Care” in
the Index.
Brake Wear
Your vehicle 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 pushim on the brake
pedal firmly).
A CAU‘
The brake wear warning sound means that soon
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.
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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.
Properly torqued wheel nuts are necessary to help
prevent brake pulsation. When tires are rotated, inspect
brake pads for wear and evenly torque
wheel nuts in the
proper sequence to
GM specifications.
Brake linings should always be replaced as complete
axle sets.
See “Brake System Inspection” in Section
7 of this manual
under Part
C “Periodic Maintenance Inspections.”
Brakc Jedal 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.
Brake Adjustment
Every time you make a brake stop, your disc brakes
adjust for wear.
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.
Your vehicle was designed and tested with top-quality
GM brake parts. 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 approved 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.
Battery
Every new vehicle has an ACDelco Freedom@ battery.
You never have to add water to one of these. When it’s
time for a new battery, we recommend an ACDelco
Freedom battery. Get one that has the replacement
number shown on the original battery’s label.
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NOTICE:
The wrong wheel can also cause problems with
bearing life, brake cooling, speedometer or
odometer calibration, headlamp aim, bumper
height, vehicle ground clearance and tire
clearance to the body and chassis.
See “Changing a Flat Tire” in the Index for
more information.
Used Replacement Wheels
I
Putting a used wheel on your vehicle is
dangerous. You can’t know how it’s been used or
how far it’s been driven. It could fail suddenly
and cause an accident.
If you have to replace a
wheel, use a new GM original equipment wheel.
Tire Chains
NOTICE:
Don’t use tire chains. They can damage your
vehicle because there’s not enough clearance.
Use another type of traction device only if its
manufacturer recommends it for use on your
vehicle and tire size combination and road
conditions. Follow that manufacturer’s
instructions.
To help avoid damage to your
vehicle, drive slowly, readjust
or remove the
device
if it’s contacting your vehicle, and don’t
spin your wheels.
If you do find traction devices that will fit, install
them on the rear tires.
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FuseKircuit Usage
Breaker
2
3
4
8
9
10
11
12 Cigarette
Lighter, Data
Link Connector
Cruise Control Module and
Switch, Body Control Module,
Heated Seats
Gages, Body Control Module,
Instrument Panel Cluster
Interior Lights
Not Used
Power Outside Mirror, Power
Lock Relay
Courtesy Lamps, Battery
Run-Down Protection
Not Used
Turn Signal
Cluster, Engine Control Module
Parking Lamps, Power Window
Switch, Body Control Module,
Ashtray Lamp
FuseKircuit
Breaker
13
14
15
16
17
18
19
20
21
22
23
24
Usage
Auxiliary Power
Power Locks Motor
4WD Switch, Engine Controls (VCM, PCM, Transmission)
Air Bag
Front Wiper
Not Used
Radio Battery
Amplifier
HVAC
I (Automatic), HVAC
Sensors (Automatic)
Anti-Lock Brakes
Rear Wiper
Radio, Ignition
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Name
RT TRN
RR PRK
TRL PRK
LT HDLP
RT HDLP
LT HI
RT HI
FR PRK
INT BAT
ENG
I
ECM B
ABS
ECM
1
HORN
BTS
I
BIU LP
IGN E
AIC
RAP
OXYSEN
Usage
Right Turn Signal Rear
Right Rear Parking Lamps
Trailer Park Lamps Left Headlamp
Right Headlamp
Left High Beam
Right High Beam
Front Parking Lamps
I/P Fuse Block Feed
Engine SensorsISolenoids, MAP,
CAM. PURGE, VENT
Engine Control Module, Fuel Pump,
Module, Oil Pressure
Anti-Lock Brake System
Engine Control Module Injectors Horn
Brake-Transmission Shift Interlock
Back-up
Lalllps
Engine
Air Conditioning
Retained Accessory Power
Oxygen Sensor
Name
IGN B
DRL
FOG LP
IGN
A
STUD #2
PARKLP
LR PRK
IGN C
HTDSEAT ATC
RRDFOG
HVAC
TRCHMSL
RR W/W
CRANK
LD LEV
HI BEAM
HAZLP
VECHMSL
HTDMIR
STOPLP
TBC
Usage
Column Feed, IGN 2, 3,4
Daytime Running Lamps
Fog Lamps
Starting and Charging IGN
I
Accessory Feeds, Electric Brake
Parking La~nps
Left Rear Parking Lamps Starter Solenoid, Fuel Pump. PRNDL
Heated Seat
Electronic Transfer Case
Rear Defogger
HVAC System
Trailer Center High Mount Stop Light
Rear Window Wiper
Clutch Switch, NSBU Switch
Electronic Load Leveling
HID Headlamps Hazard Lamps
Vehicle Center High
Mount Stop Lamp
Heated Mirror
Stoplamps
Truck Body Computer
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Short TripKity Maintenance Schedule I
The services shown in this schedule up to 100,000 miles
( 166 000 km) should be performed after 100,000 miles
( 166 000 km) at the same intervals. The services shown
at
150,000 miles (240 000 km) should be performed at
the same interval after 150,000 miles (240
000 ktn).
See “Owner Checks and Services” and “Periodic
Maintenance Inspections” following.
Footnotes
7 The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure
to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion
of the vehicle’s ~1sefu1 life. We, however.
urge that all recommended maintenance services be
performed
at the indicated intervals and the maintenance
be recorded.
## Lubricate the front suspension, ball joints, steering
linkage, parking brake cable guides, propshaft splines.
universal joints and brake pedal springs.
+ A ~ood time to check your brakes is during tire
rotation. See “Brake System Inspection” under ”Periodic
Maintenance Inspections”
in Part C of this schedule.
.:. .:, -,-*,- Drive axle service (see “Recommended Fluids and
Lubricants“ in the Index for proper lubricant to use):
Locking Differential -- Drain fluid and refill at first
engine oil change.
At subsequent oil changes. check
fluid level and add fluid
as needed. If driving in
dusty areas or towing a trailer, drain fluid and refill
every 15,000 miles
(25 000 km).
Standard Differential -- Check fluid level and add
fluid
as needed at every oil change. If driving in
dusty areas or towing a trailer. drain fluid and refill
every
15,000 miles (25 000 km).
More frequent lubrication may be required for
hea\jy-duty
or off-l-oad use.
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I Long Tripmighway Maintenance Schedule I
The services shown in this schedule up to 100,000 miles
(166 000 km) should be performed after 100,000 miles
( 166 000 km) at the same intervals. The services shown
at
150,000 miles (240 000 km) should be performed at
the same interval after 150,000 miles (240 000 km).
See “Owner Checks and Services” and “Periodic
Maintenance Inspections” following.
Footnotes
i- The U.S. Environmental Protection Agency or the
California Air Resources Board has determined that the
failure to perform this maintenance item will not nullify
the emission warranty or limit recall liability prior to the
completion
of the vehicle’s useful life. We, however,
urge that all recommended maintenance services be
performed at the indicated intervals and the maintenance
be recorded.
## Lubricate the front suspension, ball joints, steering
linkage and transfer case shift linkage, parking brake
cable guides, propshaft splines, universal joints and
brake pedal springs.
+ A good time to check your brakes is during tire
rotation. See ‘’Brake System Inspection’’ under “Periodic
Maintenance Inspections”
in Part C of this schedule.
:k:k Drive axle service (see “Recommended Fluids and
Lubricants”
in the Index for proper lubricant to use):
Locking Differential -- Drain fluid and refill at first
engine oil change. At subsequent oil changes, check
fluid level and add fluid
as needed.
fluid as needed at every engine
oil change.
Standard Differential -- Check fluid level and add
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Starter Switch Check Brake-Transmission Shift Interlock (BTSI) Check
When you are doing this check, the vehicle could
move suddenly.
If it does, you or others could be
injured. Follow the steps below.
A CAUTION:
I
When you are doing this check, the vehicle could
move suddenly. If it does, you
or others could be
injured. Follow the steps below.
1. Before you start, be sure you have enough room
around
the vehicle.
2. Firmly apply both the parking brake (see “Parking
Brake”
in the Index if necessary) and the
regular brake.
NOTE:
Do not use the accelerator pedal, and be
ready
to turn off the engine immediately if it starts.
3. Try to start the engine in each gear. The starter
should work only in PARK (P) or NEUTRAL (N).
If the starter works in any other position, your
vehicle needs service.
1. Before you start, be sure you have enough room
around the vehicle.
It should be parked on a
level surface.
2. Firmly apply the parking brake (see “Parking Brake”
in the Index if necessary).
NOTE: Be ready to apply the regular brake
immediately if the vehicle begins to move.
3. With the engine off, turn the key to the RUN
position, but don’t start the engine. Without applying
the regular brake, try
to move the shift lever out of
PARK
(P) with normal effort. If the shift lever
moves out of PARK
(P), your vehicle’s BTSI
needs service.
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Ignition Transmission Lock Check
While parked, and with the parking brake set, try to turn
the ignition key to LOCK
in each shift lever position.
The key should turn to LOCK only when the shift
lever is in PARK (P).
The key should come out only in LOCK.
Parking Brake and Automatic Transmission
PARK
(P) Mechanism Check
b-
When you are doing this check, your vehicle
could begin to move.
You or others could be
injured and property could be damaged. Make
sure there is room in front
of your vehicle in case
it begins to roll. Be ready to apply the regular
brake
at once should the vehicle begin to move.
Park on a fairly steep hill, with the vehicle facing
downhill. Keeping your foot
on the regular brake, set the
parking brake.
0 To check the parking brake’s holding ability:
With the engine running and transmission in
NEUTRAL
(N), slowly remove foot pressure from
the regular brake pedal.
Do this until the vehicle is
held by the parking brake only.
0 To check the PARK (P) mechanism’s holding ability:
With the engine running, shift to PARK
(P). Then
release all brakes.
Underbody Flushing Service
At least every spring, use plain water to flush any
corrosive materials from the underbody. Take care
to
clean thoroughly any areas where mud and other debris
can collect.
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