warning light DODGE TRUCK 1993 Service Repair Manual

10 INTRODUCTION
•
INTERNATIONAL CONTROL AND DISPLAY SYMBOLS

ID

HIGH
BEAM P
FOG UGHTS -&
HEADLIGHTS,
PARKING UGHTS, PANEL UGHTS TURN SIGNAL A
HAZARD WARNING WINDSHIELD
WASHER
WINDSHIELD WIPER WINDSHIELD WIPER
AND WASHER WINDSCREEN DEMISTING
AND DEFROSTING *

VENTILATING
FAN 8
M f

REAR
WINDOW DEFOGGER
sp

REARWINLX)W WIPER
CD
l
m

REAR
WINDOW WASHER FUEL ENGINE COOLANT
TEMPERATURE BATTERY CHARGING
CONDITION ENGINE OIL

SEAT
BELT

(©) (®) ky

11 J

LIGHTER

BRAKE
FAILURE
PARKING
BRAKE
FRONT HOOD
REAR
HOOD

(TRUNK)
HORN
11 J

LIGHTER
93IN-9

INTERNATIONAL VEHICLE CONTROL AND DISPLAY

SYMBOLS
The graphic symbols illustrated in the chart below
are used to identify various instrument controls. The
symbols correspond to the controls and displays that are located on the instrument panel.

•
LUBRICATION AND MAINTENANCE
0 - 9 FLUID CAPACITIES

COOLING SYSTEM
QUARTS
LITERS

POWER STEERING PINTS

LITERS

3.9L ENGINE 15.1 14.3
ALL
2.7
1.28

5.2L ENGINE
(2WD)
17.0 16.1

REAR
AXLE
PINTS
LITERS

5.2L ENGINE
(4WD)
16.5 15.6

CHRYSLER
BVa
Inch
(210
mm) 4.4
2.08
5.9L ENGINE
(2WD)
15.5 14.7

CHRYSLER
9Va
Inch
(235
mm) 4.5
2.13
5.9L ENGINE
(4WD)
15.0 14.2
DANA
60 6.0
2.84
5.9L DIESEL ENGINE (MAN.TRANS.) 15.5 14.7
DANA
70 7.0

3.31
5.9L DIESEL ENGINE
(AUTO,
TRANS)
16.5 15.6
FRONT AXLE
PINTS

LITERS

ENGINE
CRANKCASE
QUARTS
LITERS

DANA
44
FBJ 5.6
2.65
3.9L,
5.2L & 5.9
ENGINES 4.0* 3.8*
DANA
60 F
6.5
3.07
5.9L DIESEL ENGINES 12.0*
11.4**

TRANSMISSION-AUTOMATIC

QUARTS
LITERS

FUEL TANK GALLON

LITERS
A
727 (5.9L
ENGINE) 8.4
7.9

STANDARD
3.9L & 5.2L ENGINES 22.0 83.0

A
998 (3.9L
ENGINE) 8.6
8.1
OPTIONAL 3.9L & 5.2L ENGINES 30.0 113.0

A
999 (5.2L
ENGINE) 8.6
8.1
5.9L ENGINE
{G
OR
D)
30.0 113.0

A
518 (5.2L & 5.9L
ENGINES) 10.2
9.6
AD 100
&
AW 100 34.0 128.0

TRANSMISSION-MANUAL
QUARTS
LITERS

TRANSFER
CASE
PINTS
LITERS

NV
4500
4.0
3.8

NP-205
4.5 2.13

GETRAG
360 (5
Speed)
3.5
3.3

NP-241
6.0
2.84
* Add
0.5 qt. or 0.45
liter
when
the oil filter
is
changed

*
*
Add
1 qt. or 0.9
liter
with
oil filter
change STARTING ASSISTANCE (JUMP STARTING)
WARNING:
DO NOT
ATTEMPT
TO
PUSH
OR
TOW
A
VEHICLE
TO
START
THE
ENGINE. UNBURNED FUEL COULD ENTER CATALYTIC CONVERTER
AND IGNITE AFTER
THE
ENGINE
IS
STARTED.
THIS COULD CAUSE
THE
CONVERTER
TO
OVER­ HEAT AND RUPTURE.

BOOSTER BATTERY

WARNING:
TO
PREVENT PERSONAL INJURY
OR,
DO
NOT
ALLOW BATTERY ACID
TO
CONTACT

EYES,
SKIN
OR
CLOTHING.
DO NOT
LEAN OVER
A

BATTERY WHEN CONNECTING JUMPER
CABLES.

DO
NOT
ALLOW
THE
POSITIVE
AND
NEGATIVE

CABLE
CLAMPS
TO
CONTACT EACH OTHER.
KEEP
OPEN FLAMES
AND
SPARKS
AWAY FROM
THE BATTERY ELECTROLYTE VENT HOLES.
AL­
WAYS
WEAR
EYE
PROTECTION WHEN INVOLVED

WITH
VEHICLE BATTERIES.

If it becomes necessary to use a booster battery and
jumper cables to start an engine, use the following procedure.
J9200-86

(1) Engage the parking brake. Shift the automatic
transmission to PARK (if a manual transmission, shift to NEUTRAL).
(2) Turn off all lights, and all other electrical

loads.

(3)
Observe the battery condition indicator (Fig. 5).
If the battery condition indicator is light/bright col­
ored (or yellow), replace the battery. Do not attempt
to jump start an engine when the condition indi­
cator is light/bright colored (or yellow). If the
condition indicator is dark in the center (but without a green dot), proceed with connecting the jumper ca­

bles.

WARNING:
THE
ELECTROLYTE (ACID)
IN A
DIS­
CHARGED
BATTERY
CAN
FREEZE.
DO NOT AT­

TEMPT
TO
JUMP START
AN
ENGINE BEFORE DETERMINING
THE
CONDITION
OF THE
BATTERY
ELECTROLYTE.
THE
BATTERY COULD EXPLODE
AND CAUSE SEVERE PERSONAL INJURY.
CAUTION:
Do not
permit
the
metal
surfaces
on the

vehicles
to
contact.
This
could
establish
ground

(negative)
continuity
between
the
vehicle
bodies.

This
could
cause
the
on-board
computers
to be

damaged.
In
addition
it
could
reduce
the
amount
of

current
flow
through
the
starter
motor.

0-10
LUBRICATION
AND
MAINTENANCE

•

O.K.TO

JUMP
START BATTERY
CONDITION
INDICATOR DO NOT

JUMP
START J9100-26 DARKENED
INDICATOR
WITH
GREEN
DOT
•
LETTERS
Uk-
FLUID
Lt- E:L .

DARKENED
INDICATOR
NO
GREEN
DOT •
BATTERY CHARGE
10'//
• Ft UID
L
EVEl
OK
LIGHT
OR
BRIGHT
INDICATOR

•
RAT-cci,
C
H
A
P
C;
F
R^'^Owh

AM.w-GE
FlAf StIll BE
r-
•
!
F-
r tjr r
?
STA
F
•
r
O U n
C
AI:

Fig.
5
Battery
Condition indicator
(4) Attach a red jumper cable connector clamp to
the positive (4-) terminal on the booster battery. At­
tach the other red cable connector clamp to the pos­ itive (+) terminal on the discharged battery (Fig. 6).

CAUTION:
Do not
allow
the
positive (
+
)
and
nega­

tive
(-)
cable clamps
to
contact each other.
Do not
lean over
the
battery when connecting
the
cable

clamps.

WARNING:
DO NOT
CONNECT
A
JUMPER CABLE CONNECTOR CLAMP
TO THE
NEGATIVE POST
OF

THE DISCHARGED BATTERY.

(5) Connect a black jumper cable connector clamp
to the negative (-) terminal on the booster battery. Connect the other black jumper cable connector
clamp to a good ground source on the engine that is
to be started (Fig. 7).
Verify the engine ground (negative) contact
surface area is free of grease. Make sure there is
a good connection to bare metal. The engine
ground (negative) connection must provide good
electrical continuity.
(6) Start the engine.

WARNING:
THE
USE
OF ANY
JUMPER CABLE
DIS­
CONNECTION PROCEDURE OTHER THAN
THAT
DESCRIBED
BELOW COULD RESULT
IN:
• PERSONAL INJURY CAUSED BY BATTERY
ACID SQUIRTING FROM THE BATTERY VENTS
• PERSONAL INJURY AND/OR PROPERTY DAM­
AGE CAUSED BY BATTERY EXPLOSION
• DAMAGE TO THE BOOSTER VEHICLE OR THE
DISABLED VEHICLE CHARGING SYSTEM. (7) After the engine is started, the jumper cables
must be disconnected in the following order:
• Black (negative) cable connector clamp from the
engine ground contact • Black (negative) cable connector clamp from the
negative terminal (-) on the booster battery
• Red (positive) cable connector clamps from the pos­ itive
(
+ ) terminals on both batteries

BATTERY NEGATIVE
CABLE
TERMINAL POSITIVE
JUMPER
CABLE
BATTERY

J9000-37

Fig.
6 Positive
Jumper
Cable
Connection
ENGINE BATTERY
•GROUND NEGATIVE NEGATIVE
CABLE
-JUMPER
CABLE

BATTERY
J9000-38

Fig.
7
Both
Jumper
Cables
Connected
On
Disabled
Vehicle PORTABLE STARTING UNIT
There are many types of portable starting units
available for starting engines. Follow the manufac­
turer's instructions.

VEHICLE
LIFTING RECOMMENDATIONS
Refer to the Owner's Manual for emergency vehicle
lifting procedures.
FLOOR JACK When properly positioned, a floor jack can be used
to lift a vehicle (Fig. 8). Support the vehicle in the
raised position with jack stands at the front and rear ends of the frame rails.

CAUTION:
Do not
attempt
to lift a
vehicle with
a

floor jack positioned under:

•

LUBRICATION
AND
MAINTENANCE
0 - 15
DIESEL
ENGINES

The Diesel engine oil level indicator is located at
the left center of the engine, above the
fuel
injection

pump (Fig. 3).

Fig.
3
Diesel
Engine
Oil
Dipstick

ACCEPTABLE
OIL
LEVEL
To maintain proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
For gasoline engines, the acceptable levels are indi­ cated between the ADD and
FULL
marks on oil
dip­
stick. For Diesel engines, the acceptable levels are
indicated between the L (low) and H
(high) marks
on
oil dipstick. The oil level should be checked periodically. The
vehicle should be on a level surface. Wait for
five
minutes after stopping the engine. For gasoline en­
gines,
add oil only when the level indicated on the
dipstick is at or below the ADD mark. For Diesel en­
gines,
add oil only when the level indicated on the
dipstick is between the L and H marks.
Never oper­
ate a Diesel
engine when
the oil
level
is below
the L mark. The distance between the L and H
marks represents 1.9L (2 Qts) engine oil.

CAUTION:
Do not
overfill
an
engine crankcase
with

oil. This
will
cause
oil
aeration
and
result
in a de­

crease
in the
engine
oil
pressure.
ENGINE
OIL
CHANGE AND FILTER REPLACEMENT

WARNING: PROTECTIVE CLOTHING
AND
GLOVES SHOULD
BE
WORN. EXPOSED SKIN SHOULD
BE

WASHED
WITH
SOAP
AND
WATER
TO
REMOVE
USED
ENGINE
OIL.
DO NOT
USE
GASOLINE, THIN­
NER,
OR
SOLVENTS
TO
REMOVE ENGINE
OIL

FROM
SKIN.
DO NOT
POLLUTE. DISPOSE
OF
USED
ENGINE
OIL
PROPERLY.
ENGINE
OIL
FILTER

All engines are equipped with a throw-away type
oil filter. The same type of filter is recommended
when the filter is changed.

OIL CHANGE
AND
FILTER
REPLACEMENT
Bring engine up to normal operating temperature.
A more complete drainage of oil will result.
(1) Remove the drain hole plug and drain the en­
gine oil from the crankcase.
(2) Install the drain hole plug with a replacement
gasket. For gasoline engines, the oil filter should be
replaced during every second engine oil change.
For Diesel engines, the oil filter should be re­
placed during every engine oil change.
(3) Rotate the oil filter counterclockwise to remove
it.
(4) Clean the engine cylinder block oil filter boss. (5) Apply a light coat of new engine oil to the rub­
ber seal on the oil filter.
(6) Install and hand tighten the oil filter 1/2 to 3/4
of a turn clockwise. (7) Add new engine oil at the fill hole location on
top of the engine cylinder head cover. Wipe off any spilled oil.
(8) Observe the oil level on the dipstick.

CAUTION:
Do not
overfill
the
engine crankcase
with

oil.
(9)
Start the engine. Observe the oil pressure
gauge or warning lamp (as applicable). If the oil
pressure does not increase, stop the engine immedi­ ately. Check oil level.

COOLING SYSTEM

WARNING:
USE
EXTREME CAUTION WHEN
THE
ENGINE
IS
OPERATING.
DO NOT PUT
YOUR
HANDS NEAR
THE
DRIVE BELT(S), PULLEYS
OR
FAN BLADE.
DO NOT
STAND
IN A
DIRECT LINE
WITH
THE FAN
BLADE.

INSPECTION SCHEDULE
Determine the coolant level. Inspect the cooling
system hoses/clamps after each service interval has
elapsed.

COOLANT LEVEL
It is recommended that the engine coolant level be
inspected at least once a month during periods of hot
weather.
With the engine at normal operating temperature,
check the coolant level in the coolant reserve tank.
The coolant level must be at least above the ADD mark. Add coolant to the coolant reserve tank only.

0-18
LUBRICATION
AND
MAINTENANCE

•
COOLANT FREEZE PROTECTION

Cooling systems contain a 50/50 mixture of anti­
freeze (ethylene glycol) and distilled water. This is
the recommended coolant mixture.
It is recommended that the degree of coolant pro­
tection be tested every 12 months. If the coolant is
contaminated or rusty, the cooling system should be
drained, flushed. Refill with a 50/50 mixture of fresh
coolant. Refer to Group 7—Cooling Systems for addi­
tional information.

SYSTEM
INSPECTION

WARNING:
IF THE
ENGINE
HAS
BEEN RECENTLY
OPERATED,
DO NOT
REMOVE
THE
RADIATOR

CAP.
THIS WILL AVOID
YOU
BEING SCALDED

WITH
HOT, PRESSURIZED COOLANT.

(1) Test the radiator cap for proper sealing and op­
eration. Use caution when removing the radiator cap
to avoid contact with hot coolant. Place a heavy rag
or towel over the cap and turn to the first stop. Do
not press down. Pause to allow the pressure to re­
lease through the overflow tube. Then press down
and turn counterclockwise to remove the cap.
(2) Inspect the coolant overflow tubing and the
connections at the coolant reserve tank and at the
radiator.
(3) Inspect the entire cooling system for leaks. A
black-light detector can be used as an aid in detect­ ing the source of coolant leaks.
(4) Inspect the radiator and air conditioner con­
denser fins for debris, etc. (5) If necessary, refer to Group 7—Cooling Systems
for additional information and service procedures.

RADIATOR CAP
The radiator cap must be completely tightened to
provide proper pressure. Inspect and test radiator cap
when cooling system service is performed.

MAIN,
FLUSH
AND
FILL

WARNING: ANTI-FREEZE (ETHYLENE GLYCOL)
IS
POISONOUS.
KEEP
OUT OF THE
REACH
OF
CHIL­

DREN.

Drain, flush, and fill the cooling system at the in­
terval specified in maintenance schedule. For proper service instructions see Group 7, Cooling System.

HOSES AND
FITTINGS
It is recommended that rubber hoses be periodi­
cally inspected. Inspect all hose fittings for looseness and corrosion.
ENGINE
AIR
CLEANER
FILTER
ELEMENT

MAINTENANCE
SCHEDULE
With normal driving conditions, the engine air
cleaner filter element should be replaced:
• Light-Duty Cycle-after each 48 000 km (30,000
miles) interval has elapsed
• Heavy-Duty Cycle-after
each
38 000 km (24,000
miles) interval has elapsed
When the vehicle is operated in dusty areas, the
filter element should be replaced more often.
For Diesel engines, the air filter canister should be
cleaned at the same time the filter is replaced.

SERVICE/REPLACEMENT
(1) Remove the air cleaner cover.
(2) Remove the air cleaner filter (Fig. 4).

CAUTION:
Do not tap the filter or immerse the filter medium in liquid to remove trapped debris.
(3) Clean filter by blowing the trapped debris from
the filter with compressed air (Fig. 5). Direct the air in the opposite direction of normal intake air flow.
Keep the air nozzle at least two inches away from
the filter.
(4) If the filter has become partially saturated with

oil,
replace the filter. Inspect the crankcase ventilat­
ing system for proper operation.
(5) Wash the air cleaner cover and body with
cleaning solvent. Wipe it dry.
(6) Install the air cleaner filter element. Attach
the cover to the body (Fig. 4).
Fig,
4
Engine
Air Oeaner—
Typical

0
- 21
LUBRICATION
AND
MAINTENANCE

• SERVICE INFORMATION
All vehicles are equipped with a maintenance-free
(MF) battery when shipped from the factory (Fig. 10).
A maintenance-free battery does not have removable
cell caps and does not require additional water. Each MF battery has a visual battery condition in­
dicator (Fig. 11). When an adequate battery charge

exists,
the indicator will have a GREEN dot. When
battery charging is necessary, the indicator will be dark. When the indicator is light brown colored or
yellow, the battery should be replaced.
INSPECTION

WARNING; WEAR SAFETY
GLASSES,
RUBBER
GLOVES
AND
PROTECTIVE CLOTHING WHEN SER­
VICING
A
BATTERY.
THE
BATTERY ELECTROLYTE CONTAINS SULFURIC ACID
AND
WILL CAUSE HARM
IF IT
CONTACTS SKIN, EYES
OR
CLOTHING.
IF SULFURIC ACID CONTACTS SKIN
OR
EYES,
GET

IMMEDIATE MEDICAL ATTENTION.
DO
NOT
SMOKE
IN
THE
VICINITY
OF A
BATTERY. KEEP OPEN
FLAMES
AND
SPARKS AWAY FROM BATTERY
FILLER CAPS BECAUSE EXPLOSIVE
GAS IS AL­

WAYS
PRESENT.

Battery maintenance should be completed before
the beginning of every winter season.
Use the following battery maintenance and inspec­
tion procedure. (1) Disconnect the battery negative cable and then
the positive cable.
(2) Clean the battery cables and terminal posts
with a wire brush and a battery terminal cleaner. (3) Remove the battery holddown strap. Clean the
battery tray with a solution of baking soda and wa­
ter. Rinse and dry the battery tray.
(4) Position the battery in the tray and install the
holddown strap. Do not over-tighten the nuts.
(5) Connect the battery positive cable and then the
negative cable to the battery.
(6) Apply a small amount of chassis lubricant (or
an equivalent protective coating) to the cable termi­

nals.

RUBBER/PLASTIC
COMPONENTS

INSPECTION Components should be inspected at the same time
as scheduled underhood maintenance is conducted.
Rubber/plastic components should be replaced imme­ diately if there is any evidence of wear. Inspect the exterior surface of rubber hoses and ny­
lon tubing for evidence of heat damage. The rubber
hose and nylon tubing located close to an exhaust
manifold should be given special attention. Verify
the nylon tubing located at these areas has not col­ lapsed.
INCREASED

ELECTROUTE CAPACITY
SEALED

VENT
CAPS TEST
INDICATOR ENVELOPE

SEPARATORS
BATTERY
HOLD DOWN
RK92

Fig. 10 Maintenance-Free (MF)
Battery

O.K. TO
JUMP START
BATTERY

CONDITION
INDICATOR
J9100-26
DARKENED
INDICATOR
WITH
GREEN
DOT
•
BATTERY CHARGE
OK '
•
FLUID LEVEL
OK

DARKENED
INDICATOR
NO
GREEN
DOT
•
BATTERY CHARGE
LOW
FLUID LEVEL
OK
LIGHT
OR
BRIGHT INDICATOR

•
BATTERY CHARGE UNKNOWN

•
FLUID uEv'EL
LOW
(CHARGE
MAY
STILL
BE
SUFFICIENT
TO
START YOUR
CAR)
Fig. 11
Battery
Condition Indicator
Inspect all the hose connections. Verify they are se­
cure and there is no fluid leakage.
ENGINE MOUNTS Inspect the rubber in the engine mounts for exces­
sive wear. Slight wear at the ends will not affect the
functioning of an engine mount. If excessive engine
movement is detected, the engine mount(s) should be
replaced.

DRIVE
BELTS

MAINTENANCE SCHEDULE Replace the drive belt(s) and adjust the drive ten­
sion at the interval specified in maintenance sched­

ule.
If necessary, refer to Group 7—Cooling Systems.

•

LUBRICATION
AND
MAINTENANCE
0 - 29
POWER STEERING SYSTEM

SERVICE SCHEDULE

FLUID
LEWEL

WARNING.
THE
POWER
STEERING
FLUID LEVEL
SHOULD
ALWAYS
BE
CHECKED
WITH THE EN­

GINE
OFF TO
PREVENT
PERSONAL
INJURY.

The power steering fluid should be checked when­
ever the engine is being serviced for other reasons. Clean the outside of the cap before removing. The
fluid should be at the proper level indicated on cap dipstick (Fig. 1).

Fig.
1
Power
Steering Reservoir & Cap—Typical
The reservoir fluid level can be determined with
the fluid either hot or cold. If the fluid level is below
the FULL HOT or FULL COLD marks on the dip­ stick, add power steering fluid. The dipstick is at­
tached to the reservoir cap (Fig. 1).
FLUID SPECIFICATION MOPAR03)Power Steering Fluid is highly recom­
mended.

FRONT
WHEEL BEARINGS
INSPECTION/LUBRICATION SCHEDULE

2WD
VEHICLES
It is recommended that 2WD front wheel bearings
be inspected for proper lubrication whenever the
brake rotors are removed or at least: • At each 39 000 km (24,000 miles) interval for ve­
hicles subject to the LIGHT DUTY CYCLE Mainte­ nance Schedule • At each 36 000 km (22,500 miles) interval for ve­
hicles subject to the HEAVY DUTY CYCLE Mainte­ nance Schedule The bearings should be cleaned and re-packed
with a high temperature, multi-purpose EP lu­
bricant.
4WD
VEHICLES

It is recommended that 4WD front wheel bearings
be inspected for proper lubrication whenever the
brake rotors are removed or at least:
• At each 24 000 km (15,000 miles) interval for ve­
hicles subject to the LIGHT DUTY CYCLE Mainte­ nance Schedule
• At each 19 000 km (12,000 miles) interval for ve­
hicles subject to the HEAVY DUTY CYCLE Mainte­ nance Schedule
For vehicles used for extensive off-road, 4WD
operation, the front wheel bearings should be in­ spected every 1 600 km (1,000 miles).
The bearings should be cleaned and re-packed
with a high temperature, multi-purpose EP lu­
bricant whenever the disc brake rotors are re­ surfaced.
INSPECTION If the lubricant:
• Is not sufficient
• Contaminated with foreign particles
• Appears dry or has been contaminated with water
to produce a milky appearance, the bearings should
be cleaned and re-packed with lubricant.

CAUTION:
Do not add
lubricant
to the
wheel
bear­
ings.
Re-pack completely. Mixing
of
different
types
of lubricants
in
wheel
bearings should
be
avoided.
This could possibly result
in
excessive thinning
and
leakage
of the
lubricant.

LUBRICATION (1) Discard the original seal.
(2) Clean the original lubricant from the bearings
and from the hub cavity (Figs. 2 and 3).
(3) Inspect the bearing rollers for indications of
pitting. Light bearing roller discoloration is consid­ ered normal. A wheel bearing must be replaced if any serious damage exists.
(4) Re-pack the bearings with a high temperature,
multi-purpose NLGI GC-LB lubricant. The use of a
bearing packer is recommended. A small amount of fresh lubricant also should be added to the hub cav­ ity.
BEARING INSTALLA TION/ADJUSTMENT (1) Install the hub/rotor (with inner bearing and
seal) on steering knuckle spindle.
(2) Install the outer bearing, the thrust washer
and the nut.
(3) Tighten wheel bearing nut to 27-34 N^m (240-
300 in. lbs.) torque while rotating hub/rotor. This
will seat the bearings.
(4) Loosen the nut 1/4 of-a-turn (90°), then tighten
it finger-tight.

•

BRAKES
BRAKES
5 - 1

CONTENTS

page

BENDIX
DISC
BRAKE
37

BRAKE
ADJUSTMENTS-BRAKE BLEEDING .. 7

BRAKE
DIAGNOSIS
3

CHRYSLER
DISC
BRAKE
27
DRUM
BRAKES-ELEVEN
INCH 46
DRUM
BRAKES-TWELVE
INCH 50

GENERAL
INFORMATION 1
MASTER
CYLINDER-COMBINATION
page

VALVE-BRAKE
LINES 10

PARKING
BRAKES
56

POWER
BRAKE
BOOSTER-BRAKE
PEDAL .. 20

POWER
BRAKE
VACUUM PUMP-DIESEL
ENGINE
...22

REAR
WHEEL ANTILOCK (RWAL)
BRAKES
.. 59

SPECIFICATIONS
65

GENERAL INFORMATION
INDEX

page

Antilock
Rear
Wheel
Brakes
1
Brake
Components 1

BRAKE
COMPONENTS
AD models are equipped with front disc and rear
drum brakes. Power assist brakes and rear wheel an­
tilock brakes are standard equipment on all models. A dual reservoir master cylinder and single or dual
diaphragm, vacuum operated power brake booster is
used for all applications. Models with the Cummins
diesel engine option are also equipped with a vacuum
pump assembly to operate the power brake booster. Front disc brake units consist of single piston, slid-
ing-type calipers with semi metallic brakeshoe lin­ ing. Vented disc brake rotors are used on all models. Bendix calipers are used on 4-wheel drive models
and on diesel engine models. Chrysler disc brake cal­
ipers are used for all other applications. Rear drum brakes are dual shoe units with an au­
tomatic adjustment mechanism. Bendix and Chrysler drum brake assemblies are used. A combination valve is used on all models. The
valve consists of a front brake metering (hold-off)
valve and a front/rear pressure differential switch. A red, brake indicator and warning light is used to
alert the driver if a pressure differential exists be­
tween the front and rear hydraulic systems. The light also alerts the driver when the parking brakes
are applied. The light is located at the left side of the
instrument cluster. An additional indicator light is used for the anti-
lock system. This light is amber and is located in the
page

Brake
Fluid/Lubricants/Cleaning
Solvents
1

Brake
Safety Precautions 2
same side of the instrument cluster as the red indi­
cator light. The antilock light alerts the driver if a system fault occurs.

ANTILOCK
REAR
WHEEL
BRAKES
All AD models are equipped with antilock rear
brakes. The system is designed to retard wheel lockup during periods of high wheel slip when brak­
ing. Retarding wheel lockup is accomplished by modu­
lating fluid pressure to the wheel brake units. Refer
to the Rear Wheel Anti-Lock Brake section for oper­ ation and service information.

BRAKE
FLUID/LUBRICANTS/CLEANING SOLVENTS Recommended fluid for all AD models is Mopar
brake fluid or equivalent meeting SAE J1703 and DOT 3 standards. Use Mopar multi mileage grease to lubricate cali­
per slide surfaces, drum brake pivot pins and shoe contact points on the backing plates. Use GE 661 or
Dow 111 silicone grease (or equivalent) on caliper
bushings and slide pins. Use fresh brake fluid or Mopar brake cleaner to
clean or flush brake system components. These are
the only cleaning materials recommended.

•

BRAKES
i - 3 BRAKE DIAGNOSIS

INDEX

page

Brake
Warning Lights
3

Diagnosing
Brake Problems .................
4

Diagnosis
Procedures
3

Low
Vacuum
Switch—Diesel
Models
3
page

Master
Cylinder/Power Booster Test
5

Power
Booster
Check
Valve Test .............
6

Power
Booster
Vacuum
Test .................
6

Testing Diesel
Engine
Vacuum
Pump
Output
.... 6

DIAGNOSIS
PROCEDURES
Brake diagnosis involves determining
if the
prob­
lem
is
related
to a
mechanical, hydraulic
or
vacuum
operated component.
A
preliminary check, road test­
ing
and
component inspection
can all be
used
to de­

termine
a
problem cause. Road testing will either verify proper brake opera­
tion
or
confirm
the
existence
of a
problem. Compo­ nent inspection will,
in
most cases, identify
the
actual part causing
a
problem. The first diagnosis step
is the
preliminary check. This
involves inspecting fluid level, parking brake action,
wheel
and
tire condition, checking
for
obvious leaks
or

component damage
and
testing brake pedal response. A road test will confirm
the
existence
of a
problem.
Final diagnosis procedure involves road test analysis and
a
visual inspection
of
brake components.

BRAKE
WARNING LIGHTS
The
red
brake warning light
is
connected
to the

parking brake switch
and to the
pressure differential switch
in the
combination valve. The
red
light will illuminate when
the
parking
brakes
are
applied
or
when
a
fluid pressure drop
oc­
curs
in the
front
or
rear brake circuit.
The
light will
also illuminate
for
approximately
2-4
seconds
at en­

gine start
up.
This
is a
self test feature designed
to

check bulb
and
circuit operation each time
the en­

gine
is
started. The amber antilock light
is
connected
to the
anti-
lock rear brake hydraulic valve.
The
light will illu­
minate
if a
fault occurs within
the
antilock system.

LOW VACUUM SWITCH-DIESEL MODELS
On diesel models,
the red
brake warning light
is
also
used
to
alert
the
driver
of a low
brake booster vacuum
condition.
The
warning light
is in
circuit with
a
vacuum
warning switch mounted
on the
driver side fender
panel.
The
vacuum side
of the
switch
is
connected
to the

power brake booster.
The
electrical side
of the
switch
is
connected
to the
brake warning light. The
low
vacuum switch monitors booster vacuum
level whenever
the
engine
is
running.
If
booster vac­
uum falls below
8.5
inches vacuum
for a
minimum
of
10 seconds,
the
switch completes
the
circuit
to the

warning light causing
it to
illuminate.
The
warning light
is
designed
to
differentiate between
a low
vac­
uum condition
and a
hydraulic circuit fault.

PRELIMINARY
BRAKE CHECK
(1) Check condition
of
tires
and
wheels. Damaged
wheels
and
worn, damaged,
or
underinflated tires
can
cause pull, shudder, tramp,
and a
condition similar
to
grab.

(2)
If
complaint
was
based
on
noise when braking,
check suspension components. Jounce front
and
rear
of

vehicle
and
listen
for
noise that might
be
caused
by

loose, worn
or
damaged suspension
or
steering compo­

nents.

(3) Inspect brake fluid level
and
condition. Note
that
the
front disc brake reservoir fluid level will drop
in
proportion
to
normal lining wear. Also note
that brake fluid tends
to
darken over time. This
is normal
and
should
not be
mistaken
for
con­
tamination.
If the
fluid
is
still clear
and
free
of

foreign material,
it is OK.

(a)
If
fluid level
is
abnormally
low,
look
for
evi­
dence
of
leaks
at
calipers, wheel cylinders, brake-
lines
and
master cylinder.
(b)
If
fluid appears contaminated, drain
out a

sample.
If
fluid
is
separated into layers,
or
obvi­
ously contains
oil or a
substance other than brake
fluid,
the
system seals
and
cups will have
to be re­

placed
and the
hydraulic system flushed.
(4) Check parking brake operation. Verify free
movement
and
full release
of
cables
and
pedal. Also
note
if
vehicle
was
being operated with parking
brake partially applied.
(5) Check brake pedal operation. Verify that pedal
does
not
bind
and has
adequate free play.
If
pedal
lacks free play, check pedal
and
power booster
for be­

ing loose
or for
bind condition.
Do not
road test until
condition
is
corrected.
(6)
If
components checked appear
OK,
road test
the

vehicle.

ROAD
TESTING (1)
If
complaint involved
low
brake pedal, pump
the pedal
and
note
if the
pedal comes back
up to
nor­ mal height.
(2) Check brake pedal response with transmission
in Neutral
and
engine running. Pedal should remain
firm under steady foot pressure.

5
- 6
BRAKES

• (c) On diesel models, vacuum pump hose or
pump component may have malfunctioned. Check
pump output with vacuum gauge and repair as necessary. Refer to service procedures in Power
Booster/Vacuum Pump section.
(6) Rebuild booster vacuum reserve as follows: Re­
lease brake pedal. Increase engine speed to 1500
rpm, close throttle and immediately turn off ignition. (7) Wait a minimum of 90 seconds and try brake ac­
tion again. Booster should provide two or more vacuum assisted pedal applications. If vacuum assist is not pro­
vided, perform booster and check valve vacuum tests.
Also check vacuum output on diesel models.

POWER
BOOSTER
CHECK
VALVE
TEST
(1) Disconnect vacuum hose from check valve.
(2) Remove check valve and valve seal from
booster (Fig. 1). (3) Hand operated vacuum pump can be used for
test (Fig. 2). (4) Apply 15-20 inches (50-67 kPa) vacuum at
large end of check valve (Fig. 1). (5) Vacuum should hold steady. If gauge on pump
indicates any vacuum loss, valve is faulty and must
be replaced.
BOOSTER

CHECK
VALVE
APPLY
TEST
\
VACUUM
HERE

Fig.
1
Vacuum
Check
Vaive
And
Seal
J9005-80

Fig.
2 Typical
Hand
Operated
Vacuum
Pump

POWER
BOOSTER
VACUUM
TEST
(1) Connect a vacuum gauge to the booster check
valve with a short length of hose and a T-fitting (Fig.

3).
(2) Start and run engine at idle speed for one
minute.
(3) Clamp hose shut between vacuum source and
check valve (Fig. 3).
(4) Stop engine and observe vacuum gauge.
(5) If vacuum drops more than one inch vacuum
(33 millibars) within 15 seconds, either booster dia­
phragm or check valve are faulty.
SHORT

CONNECTING
CHECK

VACUUM
GAUGE

J9005-81
Fig.
3
Booster
Vacuum
Test
Connections

TESTING
DIESEL
ENGINE
VACUUM
PUMP
OUTPUT
On models with a Cummins turbo diesel engine, a
low vacuum condition in the brake booster will cause
the brake warning light to illuminate. The following test checks output and condition of the
vacuum pump and interconnecting hoses. However, a
more comprehensive testing procedure is provided in
the Power Brake Booster-Brake Pedal-Vacuum Pump section. Refer to the procedure for "Diagnosing A Low
Vacuum Condition" in that section. (1) Check pump vacuum and booster hoses and
connections. Make sure hoses are in good condition and securely attached. Run engine and check for vac­
uum leaks. Replace leaking hoses before proceeding. (2) Disconnect vacuum hose at booster and connect
vacuum gauge to hose end. (3) Run engine at curb idle speed and note vacuum
reading. Then run engine at 1/2 to 3/4 throttle and
note vacuum reading again. (4) Vacuum should range from 8.5 to 25 inches
vacuum at various throttle openings. Vacuum should
hold steady and not drop below 8.5 inches. (5) If vacuum output is OK, check booster and
check valve as described in this section. However, if
vacuum is low, or does not hold steady, vacuum
hoses or pump components are faulty.