key CHEVROLET PLYMOUTH ACCLAIM 1993 Service Manual

The power steering pump drive belt should be in-
spected at the time and distance interval described in
the Lubrication and Maintenance Schedules. Refer to
the General Information section of this group.
POWER STEERING FLUID INSPECTION
WARNING: ENGINE MUST NOT BE RUNNING WHEN
INSPECTING POWER STEERING FLUID LEVEL,
PERSONAL INJURY CAN RESULT.
CAUTION: Do not over fill power steering reservoir
when adding fluid, seal damage and leakage can re-
sult.
TO INSPECT FLUID LEVEL:
(1) Position vehicle on a level surface with engine
at normal running temperature. (2) Turn OFF engine and remove ignition key.
(3) Using a wiping cloth, clean oil and dirt residue
from around power steering reservoir cap. (4) Remove reservoir cap or dipstick and wipe off
fluid. (5) Install cap or dipstick.
(6) Remove cap or dipstick. Holding handle or cap
above tip of dipstick, read fluid level (Fig. 4, 5, or 6).
Add fluid if reading is below cold level mark on dip-
stick.
REAR WHEEL BEARINGS
INSPECTION
The rear wheel bearings should be packed with
new lubricant at the distance interval described in the Lubrication and Maintenance Schedules. Refer to
the General Information section of this group. The
bearings should be inspected for contamination and
wear before they are cleaned. Slight discoloration of
bearing rollers and race cup is normal. If metal
Fig. 3 Ball Joint Lubrication
Fig. 4 Power Steering Reservoir DipstickÐ2.2L or 2.5L Engine
Fig. 5 Power Steering Reservoir DipstickÐ3.0L Engine
Fig. 6 Power Steering Reservoir DipstickÐ3.3L or3.8L Engine
0 - 20 LUBRICATION AND MAINTENANCE Ä

BRAKE RESERVOIR LEVEL INSPECTION
WARNING: DO NOT ALLOW PETROLEUM OR WATER
BASE LIQUIDS TO CONTAMINATE BRAKE FLUID,
SEAL DAMAGE AND BRAKE FAILURE CAN RESULT.
RELIEVE PRESSURE IN ANTI-LOCK BRAKE SYS-
TEM BEFORE ADDING BRAKE FLUID TO RESER-
VOIR. IF NOT, BRAKE FLUID COULD DISCHARGED
FROM THE RESERVOIR POSSIBLY CAUSING PER-
SONAL INJURY.
The brake reservoir level should be inspected when
other under hood service is performed. It is normal
for the reservoir level to drop as disc brake pads
wear. When fluid must be added, use Mopar, Brake
Fluid or equivalent. Use only brake fluid conforming
to DOT 3, Federal, Department of Transportation
specification. To avoid brake fluid contamination, use
fluid from a properly sealed container. On vehicles with anti-lock brakes, depressurize the
system before inspecting fluid level. Turn OFF the
ignition and remove the key. Pump the brake pedal
at least 50 times to relieve the pressure in the sys-
tem.
On all vehicles, if fluid should become low after sev-
eral thousand kilometers (miles), fill the reservoir to
level marks on the side of the reservoir (Fig. 8 or 9).
HEADLAMPS
The headlamps should be inspected for intensity
and aim whenever a problem is suspected. When lug-
gage compartment is heavily loaded, the headlamp
aim should be adjusted to compensate for vehicle
height change. For proper service procedures, refer to
Group 8L, Lamps. DRIVER SUPPLEMENTAL AIRBAG SYSTEM
If the AIRBAG indicator lamp does not light at all,
stays lit or lights momentarily or continuously while
driving, a malfunction may have occurred. Prompt service is required. Refer to Group 8M, Restraint
Systems for proper diagnostic procedures.
BODY LUBRICATION
Body mechanisms and linkages should be inspected,
cleaned and lubricated as required to maintain ease of
operation and to prevent corrosion and wear. Before a component is lubricated, oil, grease and dirt
should be wiped off. If necessary, use solvent to clean
component to be lubricated. After lubrication is com-
plete, wipe off excess grease or oil. During winter season, external lock cylinders should
be lubricated with Mopar, Lock Lubricant or equiva-
lent to ensure proper operation when exposed to water
and ice. To assure proper hood latching component operation,
use engine oil to lubricate the lock, safety catch and
hood hinges when other under hood service is per-
formed. Mopar, Multi-purpose Grease or equivalent
should be applied sparingly to all pivot and slide
contact areas.
USE ENGINE OIL ON:
² Door hingesÐHinge pin and pivot points.
² Hood hingesÐPivot points.
² Luggage compartment lid hingesÐPivot points.
USE MOPAR LUBRIPLATE OR EQUIVALENT ON:
² Door check straps.
² Hood counterbalance springs.
² Luggage compartment lid latches.
² Luggage compartment lid prop rod pivots.
² Ash tray slides.
² Fuel Fill Door latch mechanism.
² Park brake mechanism.
² Front seat tracks.
Fig. 8 Anti-lock Brake Reservoir
Fig. 9 Master Cylinder Brake ReservoirÐExcept
Anti-lock
0 - 22 LUBRICATION AND MAINTENANCE Ä

(3) Check solenoid to volume canister joint.
² Front strut to solenoid valve connection.
² Rear spring to solenoid valve connection.
(4) Check air line for ruptures, cuts, splits or heat
damage. Use a soap and water solution or a liquid de-
veloped for leak detection.
SYSTEM OPERATION
ENGINE RUN OPERATION
The system will compensate for load
addition/removal when.
² The trunk and all doors are closed.
² The engine speed exceeds 600 R.P.M.
² Throttle angle is less than 65 degrees.
² The brake is not applied.
² You are not cornering above 10 mph.
² There is not a charging system problem with the
vehicle.
ENGINE OFF OPERATION
After passengers/load is removed from the vehicle
the system will correct the vehicle attitude after:
² The trunk and all doors are closed.
² The ignition switch is in the OFF position.
Opening the a door or trunk wakes up the body
computer and the air suspension module. The air
suspension system is now capable of leveling, if
required.
LONG TERM IGNITION OFF OPERATION
The system is capable of one an additional leveling
cycle. After 2 continuous hours of ignition key off and
no door open or trunk open activities. This feature is
implemented to eliminate possible ice freeze-up be-
tween the tire and the inner fender shield.
SYSTEM OPERATION INHIBITORS
The air suspension system is inhibited when:
² The trunk is open.
² A door(s) is/are open.
² The brake pedal is engaged.
² The throttle is at the wide open position.
² The charging system fails.
The maximum compressor pump or exhaust
time is 3 minutes.
SYSTEM FAILURES
Vehicles equipped with air suspension and overhead
console. Will alert the driver of an air suspension
system malfunction. A warning Check Air Suspension
will appear on the overhead console screen.
SAFETY CONCERNS
WARNING: REAR AIR SPRINGS MUST BE DEFLATED
BEFORE BEING REMOVED FROM THE VEHICLE.
WARNING: OPEN TRUNK, OR DOOR(S) OR REMOVE
GROUND STRAP FROM BATTERY BEFORE HOIST-
ING OR JACKING A VEHICLE DURING MECHANICAL
REPAIRS.
WARNING: IF THE VEHICLE NEEDS SERVICE OR
REPAIR OF THE REAR SHOCK ABSORBERS OR
REAR AXLE PIVOT BUSHINGS. THE REAR AIR
SPRINGS MUST HAVE THE AIR PRESSURE RE-
MOVED BEFORE THE VEHICLE CAN BE SERVICED
SAFELY.
SHIPPING MODE
(1) Removing shipping height signal for customer
use.
² Use DRB II tester and 1991 Chassis (Air Suspen-
sion) service cartridge.
² Follow DRB II requirements to cancel shipping
height message in the body computer.
² Connect the Ignition Off Draw (I.O.D.) circuit.
The connection of the IOD circuit will cancel
the Shipping height signal. (2) Return to shipping height.
² Set shipping command in the body computer using
the DRB II and the 1991 Chassis (Air suspension)
service cartridge.
² Disconnect the I.O.D. connector.
DIAGNOSIS
INITIAL DIAGNOSTIC CHECK
(1) Check for blown or missing fuses.
Fig. 9 Compressor Current Draw Test
2 - 78 SUSPENSION AND DRIVESHAFTS Ä

(2) Check all connectors for correct assembly. Check
all connectors for incorrectly installed termi-
nals. (3) Check pin #21 for minimum of 9.5 volts.
(4) Check pin #20 for minimum of 9.5 volts (with
ignition key on). (5) Check voltage at pins #5 and #16. The measure-
ment should exceed 0 volts. (6) Check pin #19 for continuity.
(7) The engine speed should exceed 680 rpm during
idle. All doors and trunk must be closed for the
system to function.
DIAGNOSTICS PROCEDURES
(1) Use the D.R.B. II tester and the 1991 air suspen-
sion diagnostic service cartridge to begin the trouble-
shooting process. (2) Use the D.R.B. mating connector under the dash
(drivers side) to plug-in the D.R.B. II test connector
(Fig. 10). (3) The tester will conduct a complete check of the
suspension system status. (4) The tester will list the steps to follow to access
and diagnose the failure. (5) A Volt/Ohm meter can be used for some diagnos-
tic testing.
HEIGHT SENSOR CHECK
If a sensor signal/signals are missing. Follow the
repair procedure listed below. (1) Check ground circuit continuity. (Remember
front and rear grounds are on different circuits. (2) For front ground circuit continuity check circuit
S 33. (3) For rear ground circuit continuity check circuit
X20. (4) Refer to control module pin out chart and wiring
diagram (see Group 8F in wiring diagram manual) for
individual circuit details. (5) If open circuits are not found replace the compo-
nent. Complete circuit testing and connector assem-
blies before replacing a strut or right rear shock. (6) To measure resistance values, see Height Sensor
Logic Chart and Initial Diagnostic Check in System
Operation.
HEIGHT SENSOR LOGIC CHART
Ä SUSPENSION AND DRIVESHAFTS 2 - 79

SERVICE ADJUSTMENTS INDEX
page page
Adjusting Rear Service Brakes ............... 4
Bleeding Brake System ..................... 6
Brake Hose and Tubing ................... 11
Master Cylinder Fluid Level .................. 4 Stop Lamp Switch Adjustment (All Vehicles)
.... 13
Test for Fluid Contamination ................. 7
Testing Application Adjuster Operation ......... 6
Wheel Stud Nut Tightening .................. 7
MASTER CYLINDER FLUID LEVEL
ALL EXCEPT AC/AY BODY WITH ABS
Check master cylinder reservoir brake fluid level a
minimum of twice a year. Master cylinder reservoirs are marked with the
words fill to bottom of rings indicating proper fluid
level (Fig. 1). If necessary, add fluid to bring the level to the bot-
tom of the primary reservoir split ring. Use only Mopar tbrake fluid or an equivalent from
a sealed container. Brake fluid must conform to DOT
3, specifications. DO NOT use brake fluid with a lower boiling
point, as brake failure could result during prolonged
hard braking. Use only brake fluid that was stored in a tightly-
sealed container. DO NOT use petroleum-based fluid because seal
damage in the brake system will result.
AC AND AY BODY WITH ANTI-LOCK BRAKES
The hydraulic assembly is equipped with a plastic
fluid reservoir with a filter/strainer in the filler neck
of the reservoir. The Anti-Lock brake system requires that the hy-
draulic accumulator be de-pressurized whenever
checking the brake fluid level. To check the brake
fluid level, the following procedure should be used: (1) With the ignition switch turned to the off position
and key removed. De-pressurize hydraulic accumula-
tor by applying brake pedal approximately 40 times,
using a pedal force of approximately 220 N (50 lbs.). A
noticeable change in pedal feel will occur when accu-
mulator is de-pressurized. Continue to apply brake
pedal several times after this change in pedal feel
occurs to insure that brake system is fully de-
pressurized. (2) Thoroughly clean both reservoir caps and sur-
rounding area of reservoir, (Fig. 2) before removing
caps. This is to avoid getting dirt into the reservoir and
contaminating the brake fluid. (3) Inspect the brake fluid to see if it is at the proper
level, see instructions on top of reservoir. (FILL TO
TOP OF WHITE SCREEN ON FRONT
FILTER/STRAINER.) (4) Fill reservoir with brake fluid to top of screen
(Fig. 3) on the filter/strainer located in brake fluid
reservoir. Only use brake fluid conforming to DOT 3
specifications such as Mopar tor equivalent.
(5) Replace brake fluid reservoir caps.
ADJUSTING REAR SERVICE BRAKES
Normally, self adjusting drum brakes will not
require manual brake shoe adjustment. Al-
though in the event of a brake reline it is advis-
able to make the initial adjustment manually to
speed up the adjusting time. (1) Raise the vehicle so all wheels are free to turn.
See Hoisting Recommendations in the Lubrication And
Maintenance Section, at the front of this service
manual. (2) Remove rear brake adjusting hole rubber plug
(Fig. 4), from the rear brake shoe support plate. (3) Be sure parking brake lever is fully re-
leased. Then back off parking brake cable adjust-
ment so there is slack in the cable. (4) Insert Brake Adjuster, Special Tool C-3784, (Fig.
5) or equivalent through the adjusting hole in support
plate and against star wheel of adjusting screw. Move
handle of tool upward until a slight drag is felt when
the road wheel is rotated. (5) Insert a thin screwdriver or piece of welding rod
into brake adjusting hole (Fig. 5). Push adjusting lever
out of engagement with star wheel. Care
Fig. 1 Master Cylinder Fluid Level (All Except AC/AY
Body W/ABS)
5 - 4 BRAKES Ä

BRAKE HOSE AND TUBING
INSPECTION OF BRAKE HOSE AND TUBING
Flexible rubber hose is used at both front brakes and
at the rear axle. Inspection of brake hoses should be
performed whenever the brake system is serviced and
every 7,500 miles or 12 months, whichever comes first
(every engine oil change). Inspect hydraulic brake
hoses for severe surface cracking, scuffing, or worn
spots. Should the fabric casing of the rubber hose be
exposed due to cracks or abrasions in the rubber hose
cover, the hose should be replaced immediately. Even-
tual deterioration of the hose can take place with
possible burst failure. Faulty installation can cause
twisting and wheel, tire or chassis interference. The steel brake tubing should be inspected periodi-
cally for evidence of physical damage or contact with
moving or hot components.
INSTALLATION OF BRAKE HOSE
Always use factory recommended brake hose to en-
sure quality, correct length and superior fatigue life.
Care should be taken to make sure that the tube and
hose mating surfaces are clean and free from nicks and
burrs. Front right and left side hoses are not
interchangeable. Connections should be correct and properly made.
Use new copper seal washers on all connections using
Banjo Bolts and tighten all fittings to their specified
torques. The flexible front hydraulic brake hose should al-
ways be installed on the vehicle by first attaching the
Banjo connector to the caliper assembly. Then bolt the
intermediate hose bracket to the strut assembly allow-
ing the bracket to position the hose to prevent twisting.
Attach the hose to the body bracket and steel brake
tubing. Tighten all fittings to specified torque. The
body bracket and hose end are keyed so that they will
only fit one way. Install rear brake hoses first to the trailing arm
tubes and then to the floor pan tubes. Minimize hose
twisting. Vehicles equipped with rear disc brakes have
brake hoses attached to the caliper on each side. The
brake hose should be first attached by the Banjo bolt to
the caliper and then secured to the hose bracket with
the retaining clip. The attach the steel brake tubing to
the hose fitting.
REPAIR AND INSTALLATION OF BRAKE TUB- ING
Only double wall 4.75mm (3/16 in.) steel tubing
should be used for replacement. Care should be taken
when replacing brake tubing, to be sure the proper
bending and flaring tools and procedures are used, to
avoid kinking. Do not route the tubes against sharp edges, moving components or into hot areas. All
tubes should be properly attached with recommended
retaining clips.
TYPES OF TUBING FLARES
Two different tubing flares (Fig. 13) are used on 93
M.Y. vehicles. On some ABS brake systems the tub-
ing connections made to the hydraulic assembly use
an ISO flare. All other ABS brake system compo-
nent, tubing connections are made using a double in-
verted flare. On non-ABS brake systems all
component tubing connections use only the double in-
verted flare. No ISO flares are used.
CAUTION: ALWAYS USE THE PROPER FLARING
TOOL AND PROCEDURE, FOR THE TYPE OF
BRAKE SYSTEM THAT IS BEING SERVICED TO IN-
SURE THE INTEGRITY OF THE HYDRAULIC SYS-
TEM.
TO REPAIR OR FLARE TUBING
Using Tubing Cutter, Special Tool C-3478-A or
equivalent, cut off damaged seat or tubing (Fig. 14).
Ream out any burrs or rough edges showing on in-
side of tubing (Fig. 15). This will make the ends of
tubing square (Fig. 15) and ensure better seating of
flared end tubing. PLACE TUBE NUT ON TUB-
ING BEFORE FLARING THE TUBING.
DOUBLE INVERTED TUBING FLARES.
To make a double inverted tubing flare (Fig. 13 &
16). Open handles of Flaring Tool, Special Tool
C-4047 or equivalent. Then rotate jaws of tool until
the mating jaws of tubing size are centered between
vertical posts on tool. Slowly close handles with tub-
Fig. 13 Identifying Hydraulic Brake Tubing Flares
Ä BRAKES 5 - 11

to the rear will be lower than the front brakes. This will
prevent premature rear wheel lock-up and skid. If
hydraulic pressure is lost in one half of the diagonally
split system, the operation of the proportioning valve
in the remaining half is not effected.
ABS BRAKE PROPORTIONING VALVE OPERATION
On vehicles using the ABS braking system, screw in
proportioning valves are used in place of the conven-
tional differential pressure/proportioning valve. Each rear brake circuit has its own screw-in propor-
tioning valve which is attached to the rear brake outlet
ports of the hydraulic assembly. These valves limit
brake pressure to the rear brakes after a certain
pressure is reached. This improves front to rear brake
balance during normal braking.
Screw in proportioning valves can be identified by
the numbers stamped on the body of the valve. The
first digit represents the slope, the second digit repre-
sents the split (cut-in) point, and the arrow represents
the flow direction of the valve. Be sure that the
numbers listed on the replacement valve are the
same as on the valve that is being removed. See
(Fig. 3) for detail of the valve identification.
HYDRAULIC SYSTEM SERVICE PROCEDURES
BRAKE WARNING SYSTEM
CHECKING BRAKE WARNING SWITCH UNIT
The Red Brake Warning light will come on when
the parking brake is applied with the ignition key
turned ON. The same light will also illuminate
should one of the two service brake hydraulic sys-
tems fail.
CAUTION:Make sure air does not enter the hydrau-
lic system during this test procedure. See bleeding
without a pressure bleeder at the beginning of this
section for master cylinder fluid level checking pro-
cedures.
To test the service brake warning system lamp.
Raise the vehicle on a hoist and open a wheel cylin-
der bleeder while a helper depresses the brake pedal
and observes the warning light. If the light fails to light, inspect for a burned out
bulb, disconnected socket, or a broken or discon-
nected wire at the switch. If the bulb is not burned
out and the wire continuity is uninterrupted. Check
the service brake warning switch operation with a
test lamp between the switch terminal and a known
good ground. Be sure to fill master cylinder and
bleed brake system after correction has been made, if
necessary.
PROPORTIONING VALVES
TESTING PROPORTIONING VALVE UNIT
If premature rear wheel skid occurs on hard brake
application, it could be an indication that a malfunc-
tion has occurred with the proportioning valve unit. The proportioning valve is designed with two sep-
arate systems. One half controls the right rear
brake, and the other half controls the left rear brake.
Therefore, a road test to determine which rear brake
slides first is essential.
RIGHT REAR WHEEL SLIDES FIRST To test the proportioning valve when the right rear
wheel slides first, leave the front brakes connected to
the valve, proceed as follows: (1) Install one gauge and (TEE) of set C-4007-A
between the brake line from the master cylinder sec-
ondary port and the brake valve assembly. (2) Install the second gauge of set C-4007-A to the
right rear brake outlet port (Fig. 4). Using an
adapter tube, made from a short piece of brake tube
and (2) 3/8 x 24 tube nuts. Connect the hose to the
valve. Bleed the hose and gauge. (3) Have a helper exert pressure on the brake
pedal (holding pressure) to get a reading on the valve
inlet gauge and check the reading on the outlet
Fig. 3 ABS PROPORTIONING VALVE IDENTIFICA- TION
Ä BRAKES 5 - 27

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

Brake Warning Lamp may indicate reduced
braking ability. The following procedure should
be used to test drive an ABS complaint:(1) Ignition on. Turn the ignition to the ON position
without starting the car and wait until the Red Brake
Warning Lamp and Amber Anti-Lock Warning Lamp
turn off. This will allow the pump to charge the
accumulator to operating pressure. If the warning
lamp(s) do not turn off, go to step 3. (2) Ignition off for 15 seconds.
(3) Start car. Wait for displays to return to normal
operating mode before proceeding. (4) With Shift lever in PARK, slowly depress brake
pedal and release. (5) Drive vehicle a short distance. During this test
drive, be sure that the vehicle achieves at least 20 mph.
Then brake to at least one complete stop and accelerate
slowly back up to at least 20 mph. (6) If a functional problem with the A.B.S. system is
determined while test driving a vehicle. Refer to the
Bendix Anti-Lock 10 Diagnostics Manual for required
test procedures and proper use of the DRB II tester.
CAUTION: The following are general precautions that
should be observed when servicing and diagnosing
the ABS system and/or other vehicle systems. Failure
to observe these precautions may result in ABS
system damage.
(1) If welding work is to be performed on the vehicle
using an arc welder, the (CAB) should be disconnected
before the welding operation begins. (2) The (CAB) and hydraulic assembly 10 way con-
nectors should never be connected or disconnected with
the ignition on. (3) Some components of the ABS system are not
serviced separately and must be serviced as complete
assemblies. Do not disassemble any component which
is designated as non-serviceable. (4) Always de-pressurize the Hydraulic Accu-
mulator when performing any work that re-
quires disconnecting any hydraulic tube, flex
hose or fitting. The ABS system uses brake fluid
at high pressure. Failure to de-pressurize the
accumulator may result in personal injury
and/or damage to painted surfaces. Brake fluid will damage painted surfaces. If brake
fluid is spilled on any painted surfaces, wash off with
water immediately.
DE-PRESSURIZING HYDRAULIC ACCUMULA- TOR
The ABS pump/motor assembly keeps the hydraulic
accumulator charged between approximately 11,032
and 13,790 kPa (1600 and 2000 psi) anytime key is in the ON position. The pump/motor assembly
cannot run if the ignition is off or either battery ca-
ble is disconnected. Unless otherwise specified, the hydraulic accumu-
lator should be de-pressurized before disassembling
any portion of the hydraulic system. The following
procedure should be used to de-pressurize the hy-
draulic accumulator: (1) With ignition off, or either battery cable discon-
nected, pump the brake pedal a minimum of 40 times
using approximately 50 pounds of pedal force. A no-
ticeable change in pedal feel will occur when the ac-
cumulator becomes discharged. (2) When a definite increase in pedal effort is felt,
pump the pedal a few additional times. This will in-
sure removal of all hydraulic pressure from the
brake system.
WHEEL SPEED SENSOR CABLES
Proper installation of wheel speed sensor cables is
critical to continued ABS system operation. Be sure
that cables are installed and routed properly. Failure
to install cables in their retainers, as shown in Sec-
tion 3 of this manual. May result in contact with
moving parts or over extension of cables, resulting in
an open circuit.
MECHANICAL DIAGNOSTICS AND SERVICE
PROCEDURES
SPECIAL SERVICE TOOLS
Some diagnostic procedures in this section require
the use of special service tools. Each of these tools is
described below.
DRB II DIAGNOSTIC TESTER
Some of the diagnostic procedures that are ex-
plained in this section require the use of the DRB II
DIAGNOSTICS TESTER to insure that proper diag-
nostics are performed. Refer to those sections for
proper testing procedures and the DRB II manual for
its proper operational information.
MST-6163 PRESSURE TESTER
Some diagnostic procedures in this manual require
the use of the MST-6163 pressure gauge and adaptor
(Fig. 2). Pressure Gauge, Special Tool MST-6163 is
required to measure accumulator pressure during
certain phases of ABS operation. The pressure gauge
and adaptor should be installed as follows: (1) De-pressurize the accumulator by pumping the
brake pedal a minimum of 40 times with the ignition
off. The procedure is fully explained under De-Pres-
surizing Hydraulic Accumulator which is described
earlier in this System Diagnosis Section.
Ä ANTI-LOCK 10 BRAKE SYSTEM 5 - 89