lock CHEVROLET DYNASTY 1993 Workshop Manual

PARKING BRAKE HAND LEVER ASSEMBLY
REMOVAL AND INSTALLATION
REMOVAL (AG AND AJ BODY)
Remove ash receiver or courtesy light from rear of
console. Remove carpet from sides of console. Remove
parking brake trim cover from passenger side of con-
sole (pulls off). Load and lockout parking brake self adjuster (Fig.
6). Disconnect rear cables from equalizer bracket. Remove the 3 hold down nuts and remove hand le-
ver assembly through opening created by removing
console trim cover. Passenger seat might have to be
removed. Also, if metal tab at bottom of console pre-
vents removal of hand brake assembly, bend tab out
of the way. (Bend the tab back to original position af-
terR&Rof hand brake).
INSTALLATION (AG AND AJ BODY)
Install hand lever assembly through side opening
in console and bolt into place. Connect rear parking brake cables to equalizer.
Adjust parking brakes.
Install console trim cover, carpet, passenger seat
and rear ash receiver or courtesy light.
REMOVAL AND INSTALLATION PARKING BRAKE
SHOES
ALL WITH REAR DISK BRAKES
(1) Remove rear disc brake caliper assembly from
adapter and braking disc (See Disc Brake Shoe Re-
moval). (2) Remove rear braking disc from rear hub (See
Removing Braking Disk). (3) Remove grease cap.
(4) Remove cotter pin, lock nut, hub bearing re-
taining nut, and washer. (5) Remove hub and bearings.(See Wheel Bearing
Section) (6) Remove forward brake shoe assembly hold
down clip (Fig. 1). (7) Turn parking brake, brake shoe adjuster wheel
until adjuster is at shortest length. (8) Remove the parking brake, shoe adjuster as-
sembly (Fig. 2). (9) Remove upper parking brake, shoe to shoe
spring (Fig. 3). (10) Pull front parking brake shoe, away from an-
chor. Then remove front parking brake shoe and
lower spring (Fig. 4). (11) Remove rear parking brake shoe hold-down
clip. Then remove rear parking brake shoe assembly
(Fig. 5).
Fig. 1 Removing Brake Shoe Hold-Down Clip
Fig. 2 Removing Adjuster Assembly
Ä BRAKES 5 - 63

INSTALLING PARKING BRAKE SHOES
(1) Install rear parking brake shoe and holddown
clip (Fig. 6). (2) Install lower parking brake, shoe to shoe re-
turn spring (Fig. 7). (3) Pull forward parking brake shoe over anchor
block until properly located on adapter. (4) Install upper parking brake, shoe to shoe re-
turn spring (Fig. 8). (5) Install parking brake shoe adjuster assembly
with star wheel forward (Fig. 9). (6) Install front, parking brake shoe holddown clip
(Fig. 10). (7) Adjust parking brake shoes to a diameter to
171 mm (6.75 inch). (8) Install hub assembly on spindle.
(9) Install outer bearing, thrust washer and nut.
(10) Tighten wheel bearing adjusting nut to 27 to
34 N Im (240 to 300 in. lbs.) torque while rotating
hub. This seats the bearings. (11) Back off adjusting nut 1/4 turn (90É) then
tighten adjusting nut finger tight. (12) Position lock on nut with one pair of slots in
line with cotter pin hole. Install cotter pin. (13) Install grease cap.
(14) Install rear braking disc.
(15) Install rear, disc brake caliper on the adapter
(See Brake Shoe Removal).
Fig. 3 Removing Upper Spring
Fig. 4 Removing Shoe and Lower Spring
Fig. 5 Removing Rear Holddown Clip and Shoe
Fig. 6 Installing Rear Shoe and Hold-Down Clip
5 - 64 BRAKES Ä

MASTER CYLINDER INDEX
page page
Brake Fluid Level Sensor .................. 66
General Information ....................... 66 Master Cylinder Service Procedures
.......... 67
Testing the Master Cylinder ................. 66
GENERAL INFORMATION
The tandem master cylinder (Fig. 1) has a glass re-
inforced nylon reservoir and an anodized aluminum
body. Do not hone the bore of the cylinder, as this will
remove the anodized surface. The reservoir is indexed to prevent installation in
the wrong direction (Fig. 2). The cap diaphragms are
slit to allow atmospheric pressure to equalize on both
sides of the diaphragm. The primary and secondary outlet tubes from the
master cylinder are connected to the valve mounted
under the master cylinder. The front part of this
block connects to the secondary outlet tube and sup-
plies the right rear and left front brakes. The rear
portion of the block connects to the primary outlet
tube and supplies the right front and left rear
brakes.
BRAKE FLUID LEVEL SENSOR
The Brake Fluid Level sensor is found only in the
AJ body vehicles with the visual electronic message
center. The purpose of the sensor is to provide the
driver with an early warning message that brake
fluid in master cylinder reservoir has dropped to a
below normal. As the fluid drops below the design level the sensor
closes the warning message circuit. Approximately
15 seconds later the message BRAKE FLUID LOW
appears on the instrument panel. At this time the master cylinder reservoir should be checked and filled
to the bottom of the rings with DOT 3 brake fluid. To check the operation of the Brake Fluid Level
sensor, with ignition on and wiring still attache-
d,remove sensor from master cylinder and hold in
upright position. Within 30 seconds the instrument
panel message BRAKE FLUID LOW should appear.
Next invert the sensor. The instrument panel message
should turn off immediately. If the above sequence
occurs the sensor is operating properly. If the message
does not appear remove the wiring from the sensor and
using a jumper wire connect both sides of the plug. The
instrumental panel message BRAKE FLUID LOW
should appear within 30 seconds. If the message does
not appear a problem exists in the wiring or instru-
mentation. If the message does appear the sensor is
faulty and must be replaced. The Brake Fluid Level
sensor is not a repairable item (Fig. 2).
TESTING THE MASTER CYLINDER
Be sure master cylinder vents at both ports.
Apply pedal lightly with engine running and look for
fluid squirting or swirling into reservoirs. In this master cylinder, a special baffle reduces the
amount of fluid entering the secondary reservoir only a
small disturbance may be seen.
Fig. 1 Aluminum Master Cylinder (Cutaway View)
Fig. 2 Brake Fluid Level Sensor
5 - 66 BRAKES Ä

(7) Unfasten brackets on steel heater water line at
dash panel and left frame rail. On Manual Transmis-
sion vehicles, unfasten clutch cable bracket at shock
tower and move aside. (8) Slide the power brake unit up and to the left
(mounting holes are slotted) on the dash panel, then
tilt inboard and up to remove.
CAUTION: Do not attempt to disassemble power
brake unit as this booster is serviced ONLY as a
complete assembly.
INSTALL (1) Position power brake booster onto dash panel.
(2) Install and tighten the 4 power brake booster to
dash panel mounting nuts (Fig. 5) to 29 N Im (250 in.
lbs.) torque. (3) Install steel heater water line and clutch cable
bracket, if so equipped. (4) Carefully position master cylinder on power
brake unit. (5) Install and tighten the 2 master cylinder to
power booster mounting nuts (Fig. 4) to 29 N Im (250
in. lbs.) torque. (6) Connect vacuum hose onto the check valve, lo-
cated on the power brake unit. (7) Using lubriplate, or equivalent, coat the bearing
surface of pedal pin (Fig. 5). (8) Connect power brake booster input rod to brake
pedal pin and install a NEW retainer clip. Use only a
new retainer clip DO NOT USE the old clip. (9) Check stop light operation.
WHEEL BEARINGS
FRONT WHEEL BEARINGS
Front wheel drive vehicles are equipped with per-
manently sealed front wheel bearings. There is no
periodic lubrication or maintenance recommended for
these units. However if during servicing of the brake
system, service to the front wheel bearing is required
refer to Group 2, Suspension in this service manual.
REAR WHEEL BEARINGS
NORMAL SERVICE
The lubricant in the rear wheel bearings should be
inspected whenever the hubs are removed to inspect
or service the brake system. Or at least every 30,000
miles (48,000 km). The bearings should be cleaned
and repacked with a High Temperature Multipurpose
E.P. Grease whenever the disc brake rotors are re-
surfaced.
INSPECTION
Check lubricant to see that it is adequate in quan-
tity and quality. If the grease is low in quantity, con-
tains dirt, appears dry or has been contaminated
with water, it will appear milky. The bearings then must be cleaned and repacked.
Do not add grease to
a wheel bearing that already has grease packed
in it. Relubricate completely. Mixing of different
types of greases in wheel bearings should be
avoided since it may result in excessive thinning
and leakage of the grease.
REMOVAL AND INSTALLATION
For the servicing, removal and installation of the
rear wheel bearings follow the procedure listed below. (1) Remove the rear tire and wheel assembly.
(2) On rear disc brake equipped vehicles remove the
caliper and rotor. Support the caliper out of the way.
Do not allow the caliper to hang by the hydraulic
hose. See disc brake section in this group for caliper
removal procedure. (3) Remove grease cap, cotter pin, nut lock, nut,
thrust washer and outer wheel bearing. (4) Carefully slide hub or drum from spindle. Do not
drag inner bearing or grease seal over stub axle
(thread, bearing, and oil seal may be damaged.) Using
an appropriate tool remove the grease seal and inner
bearing from the drum or hub. Discard grease
Fig. 5 Power Brake Booster Mounting
5 - 70 BRAKES Ä

seal, a new seal should be used when reinstalling the
inner bearing. (See Fig. 1) (5) Thoroughly clean all old grease from the outer
and inner bearings, bearing cups and hub cavity (See
Fig. 1). To clean bearings, soak them in an ap-
propriate cleaning solvent. Strike the flat sur-
face of the bearing inner race against a
hardwood block several times. Immerse the
bearings in solvent between the blows to jar
grease loose and wash old particles of hardened
grease from bearings. Repeat this operation un-
til bearings are clean. Bearings can be dried
using compressed air but do not spin the bear-
ings. After cleaning, oil the bearings with engine
oil. Insert the bearing into its appropriate cup,
apply pressure to the bearing while rotating it to
test them for pitting and roughness. Replace all
worn or defective bearings. If bearing shows signs of pitting or roughness they should be
replaced. Bearings must be replaced as a set,
both the cup and the bearing need to be replaced
at the same time. If bearings are suitable for
further use, remove engine oil from bearings
using appropriate solvent and dry bearings. Re-
pack the bearings using a Multi-Purpose NLGI.
Grade 2 EP Grease such as Mopar or equivalent,
and place them in a clean covered container
until ready for installation. If a bearing packer is
not available, hand pack grease into all cavities
between bearing cage and rollers. (6) If bearings and cups are to be replaced, remove
cups from the drum or hub using a brass drift or
suitable remover. (7) Replace bearing cups with appropriate installing
tool. (8) Install inner bearing in grease coated hub and
bearing cup, and install new grease seals using the
appropriate seal installer. (9) Coat hub cavity and cup with grease.
(10) Before installing hub or drum assembly, inspect
stub axle and seal surface for burrs or roughness, and
smooth out all rough surfaces. (11) Coat the stub axle with Multi-Purpose NLGI,
Grade 2 EP grease such as Mopar or equivalent. (12) Carefully slide the hub of drum assembly onto
the stub axle. Do not drag seal or inner bearing
over the threaded area of the stub axle. (13) Install outer bearing, thrust washer and nut.
(14) Tighten the wheel bearing adjusting nut to 27 to
34 N Im (240 to 300 in. lbs.) while rotating hub or drum
assembly. This seats the bearings. (15) Back off adjusting nut 1/4 turn (90É) then
tighten adjusting nut only finger tight. (16) Position the nut lock over the bearing adjusting
nut with one pair of slots in line with the cotter pin hole
in the stub axle, and install cotter pin. (17) Install the grease caps and the wheel and tire
assemblies. Tighten wheel stud nuts to 115 N Im (85 ft.
lbs.) on all models. reinstall wheel covers if so
equipped.
Fig. 1 Rear Wheel Bearings
Ä BRAKES 5 - 71

ANTI-LOCK BRAKE SYSTEMÐBENDIX ANTI-LOCK 10 AC/Y BODY INDEX
page page
ABS Brake System Diagnostic Features ....... 92
ABS Braking System Diagnosis .............. 87
ABS Controller Anti-Lock Brake (CAB) Service Precautions ........................... 88
ABS Equipped Vehicle Performance .......... 75
ABS Hydraulic Circuits and Valve Operation .... 85
ABS System Diagnostic Connector ........... 82
ABS System General Service Precautions ...... 88
ABS System Self-Diagnostics ............... 75
ABS Warning Systems Operation ............ 75
Anti-Lock Brake System Components ......... 76 Anti-Lock Brake System Definitions
........... 72
Anti-Lock Operation and Performance ......... 73
Anti-Lock System Relays and Warning Lamps . . . 82
Controller Anti-Lock Brake (CAB) ............. 80
Electronic Components ................... 103
General Information ....................... 72
General Service Precautions ................ 93
Major ABS Components ................... 73
Mechanical Diagnostics and Service Procedures . 89
Normal Braking System Function ............. 72
On Car Hydraulic ABS Component Service ..... 93
GENERAL INFORMATION
The purpose of the Anti-Lock Brake System (ABS)
is to prevent wheel lock-up under heavy braking con-
ditions on virtually any type of road surface. Anti-
Lock Braking is desirable because a vehicle which is
stopped without locking the wheels will retain direc-
tional stability and some steering capability. This al-
lows the driver to retain greater control of the
vehicle during heavy braking.
ANTI-LOCK BRAKE SYSTEM DEFINITIONS
In this section of the manual several abbreviations
are used for the components that are in the Anti-
Lock Braking System They are listed below for your
reference.
² CABÐController Anti-Lock Brake
² ABSÐAnti-Lock Brake System
² PSIÐPounds per Square Inch (pressure)
² WSSÐWheel Speed Sensor
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions much the same as a standard brake system
with a diagonally split master cylinder. The primary
difference is that power assist is provided by hydrau-
lic power assist instead of the conventional vacuum
assist. If a wheel locking tendency is noticed during a
brake application, the system will enter Anti-Lock
mode. During Anti-Lock braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel of the vehicle
has a set of electrical solenoid valves and hydraulic
line to provide hydraulic modulation. For vehicle sta-
bility, though both rear wheel valves receive the
same electrical signal. The system can build, hold or
reduce pressure at each wheel of the vehicle. This is
determined by the signals generated by the wheel
Four-Wheel Anti-Lock Brake System
5 - 72 ANTI-LOCK 10 BRAKE SYSTEM Ä

speed sensors (WSS) at each wheel and received at
the Controller-Anti-Lock Brake (CAB).
MAJOR ABS COMPONENTS
The following is a list of major system components.
Details of all components can be found later in this
section.
HYDRAULIC ASSEMBLY
The Hydraulic Assembly (Fig. 1) provides the func-
tion of an integral master cylinder and hydraulic
booster assembly. The hydraulic assembly contains
the wheel circuit valves used for brake pressure mod-
ulation.
WHEEL SPEED SENSORS
A Wheel Speed Sensor (Fig. 2) is located at each
wheel to transmit wheel speed information to the
Controller Anti-Lock Brake (CAB).
CONTROLLER-ANTI-LOCK BRAKE (CAB)
The (CAB) (Fig. 3) is a small control computer that
receives wheel speed information, controls Anti-Lock
operation and monitors system operation.
PUMP/MOTOR ASSEMBLY
The Pump/Motor Assembly (Fig. 4) is an electri-
cally driven pump. It takes low pressure brake fluid
from the hydraulic assembly reservoir and pressur- izes it for storage in the accumulators for power as-
sist and Anti -Lock braking.
ANTI-LOCK OPERATION AND PERFORMANCE
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions much the same as a standard brake system
with a diagonally split master cylinder. The primary
Fig. 1 ABS Hydraulic Assembly
Fig. 2 Wheel Speed Sensor
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 73

difference is that power assist is provided by hydrau-
lic power assist instead of the conventional vacuum
assist. If a wheel locking tendency is noticed during a
brake application, the system will enter Anti-Lock
mode. During Anti-Lock braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel has a set of elec-
trical solenoid valves and a hydraulic line to provide
hydraulic modulation. For vehicle stability, though
both rear wheel valves receive the same electrical
signal. The system can build, hold or reduce pressure
at each wheel. Depending on the signals generated
by the wheel speed sensors (WSS) at each wheel and
received at the Controller-Anti-Lock Brake (CAB). The ABS system represents current state-of-the-art
in vehicle braking systems. The ABS system offers the driver increased safety and vehicle control during
hard braking. This is accomplished by a sophisticated
system of electrical and hydraulic components. That
differ from conventional vacuum boosted hydraulic
actuation systems. Because, there are several perfor-
mance characteristics that may at first seem differ-
ent but should be considered normal. These
characteristics are discussed below. More technical
details are discussed further in this section.
PEDAL FEEL
The ABS System uses hydraulic power assist for
both normal power assisted braking and to provide a
source of high pressure hydraulic fluid during Anti-
Lock Braking. In general, pedal feel will be similar
to that of a conventional vacuum boosted brake sys-
tem. If during an Anti-Lock stop additional force is
applied to the brake pedal, or the brake pedal is re-
leased and reapplied rapidly. The driver may notice a
very hard pedal feel. This is due to normal isolation
of the master cylinder during A.B.S. operation as
wheel brake pressure is fed from the hydraulic
booster.
ANTI-LOCK OPERATION
During Anti-Lock Braking, brake pressures are
modulated by cycling electric valves. The cycling of
these valves can be heard as a series of popping or
ticking noises. In addition, the cycling may be felt as
a pulsation in the brake pedal, although no pedal
movement will be noticed. If Anti-Lock operation oc-
curs during hard braking. Some pulsation may be
felt in the vehicle body due to fore and aft movement
of the vehicles suspension as brake pressures are
modulated. Although ABS operation is available at virtually
all vehicle speeds. It will automatically turn off at
speeds below 3 to 5 mph. Therefore wheel lock-up
may be perceived at the very end of an Anti-Lock
stop and should be considered normal.
TIRE NOISE & MARKS
Although the ABS system prevents complete wheel
lock-up, some wheel slip is desired to achieve opti-
mum braking performance. During brake pressure
modulation, as brake pressure is increased, wheel
slip is allowed to reach up to 30%. This means that
the wheel rolling velocity is 30% less than that of a
free rolling wheel at a given vehicle speed. This slip
may result in some tire chirping, depending on the
road surface. This sound should not be interpreted as
total wheel lock-up. Complete wheel lock-up normally leaves black tire
marks on dry payment. However, Anti-Lock Braking
will not leave dark black tire marks since the wheel
never reaches a locked condition. Tire marks may
however be noticeable as light patched marks.
Fig. 3 (CAB) Controller Anti-Lock Brake Module
Fig. 4 ABS Pump/Motor Assembly
5 - 74 ANTI-LOCK 10 BRAKE SYSTEM Ä

ABS EQUIPPED VEHICLE PERFORMANCE
Anti-Lock Brakes provide the driver with some
steering control during hard braking. However there
are conditions where the system does not provide any
benefit. In particular, hydroplaning is still possible
when the tires ride on a film of water. Hydroplaning
results in the vehicle tires leaving the road surface
rendering the vehicle almost uncontrollable. In addi-
tion, extreme steering maneuvers at high speed or
high speed cornering beyond limits of tire adhesion
to the road surface may cause vehicle skidding. So,
the ABS system is termed Anti-Lock instead of Anti-
Skid. One of the significant benefits of the ABS system is
that of maintaining steering control during hard
braking or during braking on slippery surfaces. It is
therefore possible to steer the vehicle while braking
on almost any road surface.
ABS SYSTEM SELF-DIAGNOSTICS
The ABS system has been designed with Self Diag-
nostic Capability. There are two self checks the sys-
tems performs every time the vehicle is started.
First, when the key is turned on the system performs
an electrical check called Start-Up Cycle. During this
check, the Red Brake Warning Lamp and the Amber
Anti-Lock Warning Lamp are illuminated. Then
turned off at the end of the test, after about 1 to 2
seconds. When the vehicle reaches a speed of about 3
to 4 miles per hour. The system performs a func-
tional check called Drive-Off. During Drive-Off. hy-
draulic valves are activated briefly to test their
function. Drive-Off can be detected as a series of
rapid clicks upon driving off the first time the car is
started. If the brake pedal is applied during Drive-
Off, the test is by-passed. Both of these conditions
are a normal part of the system self test. Most fault
conditions will set a ABS Fault Code in the (CAB),
which can be retrieved to aid in fault diagnosis. De-
tails can be found in Diagnosis Section.
ABS WARNING SYSTEMS OPERATION
The ABS system uses two methods for notifying
the driver of a system malfunction. These include the
standard Red Brake Warning Lamp and an Amber
Anti-Lock Warning Lamp, both located in the instru-
ment cluster. The purpose of these two lamps are dis-
cussed in detail below.
RED BRAKE WARNING LAMP
The Red Brake Warning Lamp, located in the in-
strument cluster, will Turn On to warn the driver of
brake system conditions that may result in reduced
braking ability. The lamp is also turned on when the
parking brake is not fully released. Conditions which
may cause the Red Brake Warning Lamp to Turn On
include: ²
Parking brake not fully released. If the parking
brake is applied or not fully released. The switch on the
parking brake pedal assembly will ground the Red
Brake Warning Lamp circuit and cause the lamp to
turn on. On vehicles equipped with mechanical instru-
ment clusters, the Amber Anti-Lock Lamp will turn on
if the vehicle is driven above 3 miles per hour with the
Parking Brake applied.
² Low brake fluid. The fluid level sensor in the hy-
draulic assembly reservoir will ground the Red Brake
Warning Lamp circuit if low brake fluid level is de-
tected. In addition, ABS will be deactivated above 3
miles per hour and the Amber Anti-Lock Warning
Lamp will be illuminated. If the vehicle is equipped
with EVIC, a low fluid condition will also cause the
Low Brake Fluid message to appear.
² Low Accumulator Pressure. In the event of low
accumulator pressure, the dual function pressure
switch in the hydraulic assembly will signal the (CAB)
to ground the Red Brake Warning Lamp circuit. This
will cause the Red Brake Warning Lamp to turn on.
Low accumulator pressure also results in the activa-
tion of the Yellow Anti-Lock Warning Lamp. Low accu-
mulator pressure may result in loss of power assist.
² Modulator Or (CAB) Faults. The modulator assem-
bly or (CAB) may turn on the Yellow Anti-Lock Warn-
ing Lamp, if certain faults are detected in either the
modulator assembly or the (CAB).
² Bulb check. As a bulb check, the Red Brake Warning
Lamp will illuminate whenever the ignition switch is
placed in the crank position. Illumination of the red Brake Warning Lamp
may indicate reduced braking ability. A vehicle
that has the Red Brake Warning Lamp ON should
not be driven except to do diagnostic procedures
described in Section 2 of this manual. Most con-
ditions that turn on the Red Brake Warning
Lamp will also turn on the Amber Anti-Lock
Warning Lamp, consequently disabling the Anti-
Lock function.
ANTI-LOCK WARNING LAMP
The Anti-Lock Warning Lamp is located in the in-
strument cluster and is Amber in color. The Amber
Anti-Lock Warning Lamp is illuminated when the
(CAB) detects a condition that results in a shutdown of
Anti-Lock function. The Amber Anti-Lock Warning
Lamp is normally on until the (CAB) completes its self
tests and turns the lamp off. For example, if the (CAB)
is disconnected, the lamp is on. Display of the Amber Anti-Lock Warning Lamp
without the Red Brake Warning Lamp indicates
only that Anti-Lock function has been disabled.
Power assisted normal braking is unaffected.
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 75

NORMAL OPERATION OF WARNING LAMPS
With the ignition in the Crank position, the Red
Brake Warning Lamp will turn on as a bulb check.
The Amber Anti-Lock Warning Lamp will turn on
for as little as 1 second to as long as 30 seconds. If the car has not been started for several hours,
for example after sitting overnight. The Red Brake
Warning Lamp and the Amber Anti-Lock Warning
Lamp may both be turned on for as long as 60 sec-
onds after turning the ignition on. This condition is
caused by the loss of accumulator charge when the
vehicle is parked for extended periods, particularly in
cold weather. When the key is then turned on. The
Pump/Motor assembly must recharge the hydraulic
accumulator to its normal operating pressure. As re-
charging is completed, both warning lamps will turn
off when accumulator pressure reaches about (1,000
psi). Both lamps should remain off at all other times,
indicating normal operation.
ANTI-LOCK BRAKE SYSTEM COMPONENTS
The following is a detailed description of the Anti-
Lock Brake System components. For information on
servicing the other Non-ABS related components
that may be referred to in this section. See the Stan-
dard Brakes Section that refers to the specific com-
ponent.
HYDRAULIC ASSEMBLY
The ABS system uses an integral Hydraulic Assem-
bly (Fig. 1). The hydraulic assembly includes a
Booster/Master Cylinder, Modulator, Hydraulic Blad-
der Accumulator and Fluid Reservoir. The Hydraulic
Assembly is located on the dash panel cowl on the
drivers side of the vehicle. The following is a descrip-
tion of the components that make up the Hydraulic
Assembly.
HYDRAULIC ASSEMBLY BRAKE FLUID RES- ERVOIR
A one piece Fluid Reservoir is attached to the hy-
draulic assembly with rubber seals. The Fluid Reser-
voir (Fig. 1) is internally separated into three fluid
sections. Most of the brake fluid is contained in the
Fluid Reservoir and hydraulic bladder accumulator
(Fig. 1). Additional fluid is contained in the
pump/motor assembly accumulator.
BOOSTER/MASTER CYLINDER
The Booster/Master Cylinder portion of the
hydraulic assembly is an integral component and
should never be disassembled. The Booster/Master Cylinder uses a diagonally split
configuration during normal braking. The two
Fig. 1 Hydraulic Assembly
5 - 76 ANTI-LOCK 10 BRAKE SYSTEM Ä