1993 CHEVROLET DYNASTY inflation pressure

PROPORTIONING VALVES
Two Proportioning Valves (Fig. 3) are used in the
system, one for each rear brake hydraulic circuit.
The Proportioning Valves function the same as in a
standard brake system. The Proportioning Valves are
located on the bottom of the hydraulic assembly (Fig.
1). They are the same screw in type as the ones used
on the Bendix Anti-Lock 10 and Bosh Anti-Lock
Brake systems.
WHEEL SPEED SENSORS
One Wheel Speed Sensor (WSS), is located at each
wheel (Fig. 4 and 5), and sends a small (AC) signal
to the control module (CAB). This signal is generated
by magnetic induction. The magnetic induction is
created, when a toothed sensor ring Tone Wheel (Fig.
6) passes a stationary magnetic Wheel Speed Sensor.
The (CAB) converts the (AC) signal generated at
each wheel into a digital signal. If a wheel locking
tendency is detected, the (CAB) will then modulate
hydraulic pressure to prevent the wheel(s) from lock-
ing. The front Wheel Speed Sensor is attached to a boss
in the steering knuckle (Fig. 4). The tone wheel is
part of the outboard constant velocity joint. The rear
Wheel Speed Sensor is mounted to the caliper adap-
tor (Fig. 5) and the rear tone wheel is an integral
part of the rear wheel hub (Fig. 6). The speed sensor
air gap is NOT adjustable. The four Wheel Speed Sensors are serviced individ-
ually. The front Tone Wheels are serviced as an as-
sembly with the outboard constant velocity joint. The
rear Tone Wheels are serviced as an assembly with
the rear brake hub. Correct Anti-Lock system operation is dependent
on the vehicle's wheel speed signals, that are gener-
ated by the Wheel Speed Sensors. The vehicle's
wheels and tires must all be the same size and type
to generate accurate signals. In addition, the tires
must be inflated to the recommended pressures for
optimum system operation. Variations in wheel and
tire size or significant variations in inflation pres-
sure can produce inaccurate wheel speed signals.
Fig. 3 Proportioning Valve Identification
Fig. 4 Front Wheel Speed Sensor
Fig. 5 Rear Wheel Speed Sensor
5 - 118 ANTI-LOCK 6 BRAKE SYSTEM Ä

WHEEL SPEED SENSORS
One Wheel Speed Sensor (WSS), is located at each
wheel (Fig. 5 and 6), and sends a small AC signal to the
control module CAB. This signal is generated by mag-
netic induction. The magnetic induction is created,
when a toothed sensor ring (Tone Wheel) (Fig. 7) passes
a stationary magnetic Wheel Speed Sensor. The CAB
converts the AC signal generated at each wheel into a
digital signal. If a wheel locking tendency is detected,
the CAB will then modulate hydraulic pressure to pre-
vent the wheel or wheels from locking.
The front Wheel Speed Sensor is attached to a boss
in the steering knuckle (Fig. 5). The tone wheel is
part of the outboard constant velocity joint (Fig. 5). The rear Wheel Speed Sensor is mounted to the cal-
iper adapter (Fig. 6) and the rear tone wheel is an
integral part of the rear wheel hub (Fig. 7). The
speed sensor air gap is NOT adjustable.
The four Wheel Speed Sensors are serviced individ-
ually. The front Tone Wheels are serviced as an as-
sembly with the outboard constant velocity joint. The
rear Tone Wheels are serviced as an assembly with
the rear brake hub. Correct Antilock system operation is dependent on
the vehicle's wheel speed signals, that are generated
by the Wheel Speed Sensors. The vehicle's wheels
and tires must all be the same size and type to gen-
erate accurate signals. In addition, the tires must be
inflated to the recommended pressures for optimum
system operation. Variations in wheel and tire size
or significant variations in inflation pressure can
produce inaccurate wheel speed signals.
CONTROLLER ANTILOCK BRAKE CAB
The Antilock Brake Controller is a small micropro-
cessor based device which monitors the brake system
and controls the system while it functions in the An-
tilock mode. The CAB is mounted on the top of the
right front frame rail and uses a 60-way system con-
nector (Fig. 8). The power source for the CAB is
through the ignition switch in the Run or On posi-
tion. THE CONTROLLER ANTILOCK BRAKE
CAB IS NOT ON THE CCD BUS The primary functions of the CAB are:
(1) Detect wheel locking tendencies.
(2) Control fluid modulation to the brakes while in
Antilock mode. (3) Monitor the system for proper operation.
Fig. 5 Front Wheel Speed Sensor
Fig. 6 Rear Wheel Speed Sensor
Fig. 7 Rear Tone Wheel (Typical)
5 - 18 ANTILOCK 4 BRAKE SYSTEM Ä

WHEELSÐTIRES
CONTENTS
page page
SPECIFICATIONS ........................ 8
TIRE SERVICE PROCEDURES .............. 1 WHEELS SERVICE PROCEDURES
........... 6
TIRE SERVICE PROCEDURES INDEX
page page
Cleaning of Tires .......................... 1
General Information ........................ 1
Pressure Gauges ......................... 2
Radial-Ply Tires ........................... 1
Repairing Leaks .......................... 3
Rotation ................................ 3 Spare TireÐCompact
...................... 1
Tire Inflation Pressures ..................... 2
Tire Noise or Vibration ..................... 3
Tire Wear Patterns ........................ 3
Tread Wear Indicators ...................... 3
GENERAL INFORMATION
Throughout this group, references may be made to a
particular vehicle by letter or number designation. A
chart showing the breakdown of these designations is
included in the Introduction Section. Tires are designed for the vehicle and provide the
best overall performance for normal operation. The
ride and handling characteristics match the vehicle's
requirements. With proper care they will give excellent
reliability traction, skid resistance and tread life. They
have load carrying capacity, when properly inflated, to
operate at loads up to the specified Maximum Vehicle
Capacity. Driving habits have more effect on tire life than any
other factor. Careful drivers will obtain, in most cases,
much greater mileage than severe or careless drivers. A
few of the driving habits which will shorten the life of
any tire are:
² Rapid acceleration and deceleration
² Severe application of brakes
² High-speed driving
² Taking turns at excessive speeds
² Striking curbs and other obstacles
Radial ply tires can be more susceptible to irregular
tread wear. It is very important to follow the tire
rotation interval shown in the section on Tire
Rotation to achieve a greater tread life potential.
RADIAL-PLY TIRES
Radial-ply tires improve handling, tread life, and
ride quality and decrease rolling resistance. Radial-ply tires must always be used in sets of four
and under no circumstances should they be used on
the front only. However, they may be mixed with temporary spare tires when necessary,
but reduced speeds are recommended. Radial-ply tires have the same load carrying capac-
ity as other types of tires of the same size. They also
use the same recommended inflation pressures.
SPARE TIREÐCOMPACT
The compact spare tire is designed for emergency
use only. The original tire should be repaired and re-
installed at the first opportunity. Refer to Owner's
Manual for complete details.
TIRE CHAINS
Tire snow chains may be used on certainmodels.
Refer to Owner's Manual for more information.
CLEANING OF TIRES
Remove protective coating on tires before delivery
of vehicle, otherwise it could cause deterioration of
tires. Remove protective coating by applying warm wa-
ter, letting it soak one minute, and then scrubbing
the coating away with a soft bristle brush. Steam cleaning may also be used for cleaning.
DO NOT use gasoline or wire brush for cleaning.
DO NOT use mineral oil or an oil-based solvent.
Ä WHEELSÐTIRES 22 - 1

PRESSURE GAUGES
High quality dial type air pressure gauges are rec-
ommended. After checking pressure with the gauge,
replace valve caps and tighten finger tight.
TIRE INFLATION PRESSURES
Under inflation (Fig. 1) causes rapid shoulder wear
and tire flexing and can result in tire failure.
Over inflation (Fig. 2) cause rapid center wear and
loss of the tire's ability to cushion shocks.
Improper inflation can cause:
² Uneven wear patterns
² Reduced tread life
² Reduced fuel economy
² Unsatisfactory ride
² The vehicle to drift.
Proper tire pressure can be found on the placard
attached to the vehicle, See Owner's Manual. This pressure has been selected to provide safe ve-
hicle operation, proper vehicle stability, and a
smooth ride. Tire pressure should be checked cold
once per month and more frequently when the weather temperature varies widely. Tire pressure will
decreases when the outdoor temperature drops.
Inflation pressures specified on the placards are
always cold inflation pressure. Cold inflation pres-
sure is obtained after the vehicle has not been
operated for at least 3 hours or driven less than
one mile after being inoperative for 3 hours. Tire
inflation pressures may increase from 2 to 6 pounds
per square inch (psi) during operation. Do NOT reduce
this normal pressure build-up. Cold inflation pressures must not exceed 240 kPa (35
psi) for P-Series standard load tires.
TIRE PRESSURES FOR HIGH-SPEED OPERA- TION
Chrysler Corporation advocates driving at safe
speeds within posted speed limits. Where speed limits
or conditions are such that the vehicle can be driven at
high speeds, correct tire inflation pressure is very
important. For speeds up to and including 120 km/h
(75 mph), tires must be inflated to the pressure shown
on the tire placard. For speeds in excess of 120 km/h
(75 mph), tires must be inflated to the maximum
pressure specified on the tire sidewall. Vehicles loaded to the maximum capacity should not
be driven at continuous speeds above 120 km/h (75
mph).
WARNING: OVERINFLATED OR UNDER INFLATED
TIRES CAN AFFECT VEHICLE HANDLING. SUDDEN
TIRE FAILURE CAN RESULT, CAUSING LOSS OF
VEHICLE CONTROL.
For police or emergency vehicles that must be driven
at continuous speeds over 144 km/h (90 mph), special
high-speed tires must be used. Consult tire manufac-
turer for tire and inflation pressure recommendations.
REPLACEMENT TIRES
The original equipment tires on the vehicle have
been engineered to provide a proper balance of many
characteristics such as:
² ride
² noise
² handling
² durability
² tread life
² traction
² rolling resistance
² speed capability
Failure to use equipment replacement tires may
adversely affect the safety and handling of the vehicle. The use of oversize tires not listed in the specification
charts may cause interference with vehicle com-
Fig. 1 Under inflation Wear
Fig. 2 Over inflation Wear
22 - 2 WHEELSÐTIRES Ä

ponents. Under extremes of suspension and steering
travel tire damage may occur.
WARNING: FAILURE TO EQUIP THE VEHICLE WITH
TIRES HAVING ADEQUATE SPEED RATING CAN
CAUSE SUDDEN TIRE FAILURE.
ROTATION
DIRECTIONAL TREAD PATTERN TIRES
Some vehicles are fitted with special high-perfor-
mance tires having a directional tread pattern de-
signed to improve traction on wet pavement. To obtain the full benefits of this design, the tires
must be installed so that they rotate in the correct
direction. This is indicated by arrows on the tire
sidewalls. When wheels and tires are being installed, extra
care is needed to ensure that this direction of rota-
tion is maintained. Refer to Owner's Manual for rotation schedule.
NONDIRECTIONAL TIRES
Tires on the front and rear axles of vehicles oper-
ate at different loads and perform different steering,
driving, and braking functions. For these reasons,
they wear at unequal rates, and tend to develop ir-
regular wear patterns. These effects can be reduced
by timely rotation of tires. Rotation will increase
tread life, help to maintain mud, snow, and wet trac-
tion levels, and contribute to a smooth, quiet ride. The suggested rotation method is the forward-cross
tire rotation method. This method takes advantage of
current tire industry practice which now allows cross
rotation of radial-ply tires. Refer to the owner's man-
ual (usually found in the glove box) for additional in-
formation. Other rotation methods may be used, but
may not have all the benefits of the recommended
method. Always check air pressure and wheel nut tightness
after rotation. Do NOT use oil or grease on studs
or nuts. Refer to Owner's Manual for rotation schedule.
TREAD WEAR INDICATORS
Tread wear indicators (Fig. 3) are molded into the
bottom of the tread grooves. When tread is 1.6 mm
(1/16 in.), the tread wear indicators will appear as a
13 mm (1/2 in.) band. Tire replacement is necessary when indicators ap-
pear in two or more grooves, or if localized balding
occurs.
REPAIRING LEAKS
For proper repairing, a radial tire must be removed
from the wheel. Repairs should only be made if the
defect or puncture is in the tread area otherwise the
tire should be replaced. Deflate tire completely before dismounting tire
from the wheel. Use lubrication such as a mild soap
solution when dismounting or mounting tire. Use
tools free of burrs or sharp edges which could dam-
age the tire or wheel rim. Before mounting tire on wheel, make sure all rust
scale is removed from the rim and repaint if neces-
sary. Install wheels on vehicle, progressively tightening
wheel nuts to 129 N Im (95 ft. lbs.) torque (See
Wheels).
TIRE NOISE OR VIBRATION
Radial-ply tires are sensitive to force impulses
caused by improper mounting, wheel irregularities,
or imbalance. To determine if the tires are causing the noise or
vibration, drive the vehicle over a smooth portion of
highway at different speeds and note the effect of ac-
celeration and deceleration on noise level. Differen-
tial and exhaust noise will change in intensity as
speed varies, while tire noise will usually remain
constant.
TIRE WEAR PATTERNS
Under inflation results in faster wear on shoulders
of tire. Over inflation causes faster wear at center of tread.
Excessive camber causes the tire to run at an angle
to the road. One side of tread is worn more than the
other. Excessive toe-in or toe-out causes wear on the
tread edges of the tire, from dragging of tire. There
is a feathered effect across the tread (Fig. 4).
Fig. 3 Tread Wear Indicators
Ä WHEELSÐTIRES 22 - 3