tire pressure DODGE TRUCK 1993 Service Repair Manual

INTRODUCTION

INTRODUCTION

DESIGNATIONS,
LABELS/PLATES/DECALS,
CODES
AND DIMENSIONS/WEIGHTS .
CONTENTS

page
MEASUREMENT
AND TORQUE
... 1 SPECIFICATIONS
page

. 11

DESIGNATIONS, LABELS/PLATES/DECALS, CODES
AND
DIMENSIONS/WEIGHTS
INDEX

page

Engine
and
Transmission/Transfer
Case
Identification
2

Engine/Transmission/GVWR
4

Equipment
Identification
Plate
3
International
Vehicle Control
and
Display
Symbols
10

Major Component
Identification 3
VEHICLE DESIGNATIONS The Vehicle Code chart lists description and code
for Ram Truck and Sport Utility vehicles. The codes are used to identify vehicle types in charts, captions
and in service procedures. The vehicle codes are
dif­

ferent than the Vehicle Identification Number (VIN) or the wheelbase/model code.
VEHICLE SAFETY CERTIFICATION
LABEL
A certification label is attached to the left side
B-pillar. The label certifies that the vehicle conforms
to Federal Motor Vehicle Safety Standards (FMVSS).
The label also lists the: • Month and year of vehicle manufacture
• Gross Vehicle Weight Rating (GVWR). The gross
front and rear axle weight ratings (GAWR's) are
based on a minimum rim size and maximum cold tire inflation pressure Vehicle Identification Number (VIN)
Type of vehicle
Type of rear wheels (single or dual) Bar code
Month, Day and Hour (MDH) of final assembly
VEHICLE IDENTIFICATION NUMBER (VIN) PLATE The Vehicle Identification Number (VIN) plate is
attached to the top left side of the instrument panel.
The VIN contains 17 characters that provide data
concerning the vehicle. Refer to the decoding chart to
determine the identification of a vehicle.
page

Trailer
Towing Specifications
4

Vehicle Code Plate
2

Vehicle Designations
1

Vehicle Dimension
4

Vehicle
Identification
Number (VIN) Plate
1

Vehicle Safety
Certification
Label
............. 1

Vehicle Weights
4
VEHICLE CODE
DESIGNATIONS
VEHICLE CODE
= AD
(DODGE
RAM

PICKUP
&
CHASSIS
CAB)

VEHICLE
FAMILY LINE DESCRIPTION
AD1
D150

AD2
D250

AD3
D350
PICKUP

4x2

AD5
W150
AD6
W250

AD7
W350
PICKUP

4x4

AD2
D250
AD3
D350
CHASSIS
CAB

4x2

AD6
W250
AD7
W350
CHASSIS
CAB

4x4

AD4
AD100

AD4
AD150
SPORT
UTILITY
4x2

AD8
AD100

AD8 AD
150
SPORT
UTILITY
4x4
J90IN-32

0 - 2
LUBRICATION
AND
MAINTENANCE

• Commercial service
When a vehicle is continuously subjected to severe
driving conditions, lubricate:
• Body components
• All the driveline coupling joints
• Steering linkage More often than normal driving conditions

DUSTY
AREAS
With this type of severe driving condition, special
care should be given to the:
• Engine air cleaner filter
• PCV filter
• Crankcase ventilation system
• Brake booster control valve air filter. Verify that the filters and the associated compo­
nents are clean. Also verify that they are functioning
effectively. This will minimize the amount of abra­ sive particles that enter the engine.

OFF-ROAD
(4WD)
OPERATION
After off-road (4WD) operation, inspect the under­
side of the vehicle. Inspect the:
• Tires
• Body structure
• Steering components
• Suspension components • Exhaust system
• Threaded fasteners

HARSH
SURFACE ENVIRONMENTS
After extended operation in harsh environments,
the brake drums, brake linings, and rear wheel bear­ ings should be inspected and cleaned. This will pre­
vent wear and erratic brake action.

ROUTINE MAINTENANCE
The following routine maintenance is recommended
on a monthly basis: TIRES—Inspect the tires for unusual wear/damage.
Determine if the inflation pressure is adequate for
the vehicle load. BATTERY—Inspect and clean the terminals.
Tighten the terminals if necessary. FLUIDS—Determine if the component fluid levels
are acceptable. Add fluid, if necessary. LIGHTS/ELECTRICAL—Test all the electrical sys­
tems in the vehicle for proper operation. It is also recommended that the engine oil and the
washer fluid level be determined at each fuel fill-up.

VEHICLE
NOISE CONTROL
Vehicles with a GVWR of 4 535 kg (10,000 lbs), or
more, are required to comply with Federal Exterior Noise Regulations (Fig. 2).
VEHICLE
NOISE
EMISSION
CONTROL INFORMATION

DATE
OF
VEHICLE
MANUFACTURE

THIS
VEHICLE CONFORMS
TO
U.S. EPA REGULATIONS FOR NOISE EMISSION

APPLICABLE
TO
MEDIUM
AND HEAVY
DUTY
TRUCKS. THE
FOLLOWING
ACTS OR THE CAUSING THEREOF BY ANY PERSON ARE PROHIBITED BY THE NOISE CONTROL ACT
OF 1972. (A) THE
REMOVAL
OR

RENDERING
INOPERATIVE, OTHER
THAN
FOR
PURPOSES
OF
MAINTENANCE,
REPAIR.
OR REPLACEMENT, OF ANY NOISE CONTROL DEVICE OR ELEMENT OF
DESIGN
(LISTED
IN
THE
OWNERS
MANUAL)
INCORPORATED
INTO
THIS
VEHICLE
IN COMPLIANCE
WITH
THE NOISE CONTROL
ACT:
(B) THE
USE
OF
THIS
VEHICLE
AFTER SUCH DEVICE
OR
ELEMENT
OF
DESIGN HAS BEEN REMOVED
OR
RENDERED
INOPERATIVE.

PU626D

Fig.
2 Vehicle
Noise
Emission
Control Information
Label

UNAUTHORIZED
DEFEAT
OF
NOISE
CONTROL COMPONENTS
Federal law prohibits removal, altering or other­
wise defeating any noise control component. This in­
cludes before or after the vehicle is in use. Federal
law also prohibits the use of a vehicle after a noise
control component is defeated.

REQUIRED MAINTENANCE/SERVICE
FOR
NOISE
CONTROL

The following maintenance is required after each
6-month or 9 600 km (6,000 miles) interval. This will
ensure that the vehicle noise control components are
operating properly.

EXHAUST SYSTEM
Inspect exhaust system for exhaust leaks and dam­
aged components. The exhaust hangers, clamps and
U-bolts should be attached and in good condition.
Burned or ruptured mufflers, damaged exhaust pipes should be replaced. Refer to Group 11—Exhaust Sys­
tem/Intake Manifold for service information.

AIR
FILTER
HOUSING/CANISTER
Inspect the air filter assembly for proper fit. Verify
the cover is securely attached to the housing/canis­
ter. Inspect all the air filter housing hoses for con­ nections. The gasket between the air filter housing and throttle body must be in good condition. The air
filter element should be clean and serviced according
to the maintenance schedule.

FUEL
REQUIREMENTS
GASOLINE
ENGINES
All engines require the use of unleaded gasoline to
reduce the effects of lead to the environment. Also unleaded fuel is necessary to prevent damage to the
catalytic converter/02 sensor. The fuel must have a
minimum octane rating of 87 based on the (R + M)/2
calculation method.

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
- 32
LUBRICATION
AND
MAINTENANCE

•

Fig.
5 Parking Brake Ratio Lever Lubrication (2) Note any indication of brake overheating,
wheel dragging or the vehicle pulling to one side.
(3) Evaluate any performance complaints received
from the owner/operator. (4) Repair the brake system as necessary (refer to
Group 5—Brakes for additional information and ser­
vice procedures).

BODY
COMPONENT
MECHANISMS
LUBRICATION REQUIREMENTS
All operating mechanisms and linkages should be
lubricated when necessary. This will maintain ease of operation and provide protection against rust and
excessive wear. The door weatherstrip seals should
be lubricated to prolong their life as well as to im­ prove door sealing.

LUBRICANT SPECIFICATIONS
All applicable exterior and interior vehicle operat­
ing mechanisms should be:
• Inspected • Cleaned
• All the pivoting/sliding contact areas on the mech­ anisms should then be lubricated.
MOPAR®Multi-Mileage Lubricant or an equiva­
lent, should be used to lubricate the mechanisms.
The door weatherstrip seals should be lubricated
with silicone lubricant spray. Refer to the Body Lu­
bricant Specifications chart below for additional lu­
bricant applications.

LUBRICATION
(1) When necessary, lubricate the cab and cargo
box operating mechanisms with the specified lubri­
cants.

(2) Apply silicone lubricant to a cloth and wipe it
on door seals to avoid over-spray that can soil pas­
senger clothing. (3) Before applying lubricant, the component
should be wiped clean. After lubrication, any excess
lubricant should be removed.
(4) The hood latch, latch release mechanism, latch
striker and safety latch should be lubricated periodi­
cally.
(5) The door lock cylinders should be lubricated 2
times each year (preferably autumn and spring): • Spray a small amount of lock cylinder lubricant di­
rectly into the lock cylinder
• Apply a small amount to the key and insert it into
the lock cylinder • Rotate it to the locked position and then back to
the unlocked position several times
• Remove the key. Wipe the lubricant from it with a
clean cloth to avoid soiling of clothing.

TIRES
RECOMMENDED MAINTENANCE
The condition of the tires should be inspected. The
inflation pressures tested/corrected at the same time as the engine oil is changed and the oil filter is re­
placed.
The tires/wheels should be rotated periodically to
ensure even tread wear. The tires/wheels should be
rotated at the first 12 000 km (7,500-miles) interval.
Thereafter, at each 24 000 km (15,000-miles) inter­
val.
INSPECTION
Inspect the tires for excessive wear, damage. Test
the tires for the recommended inflation pressure and adjust the pressure accordingly. Refer to the tire in­
flation pressure decal located on the left door face. Also to Group 22—Tires And Wheels for tire pres­sure charts, tire replacement, and treadwear indica­

tors.

ROTATION
Tires/wheels should be rotated according to the rec­
ommended interval. The first tire/wheel rotation is
the most important for establishing the prevention of uneven tread wear. After rotation, adjust the tire in­
flation pressure to the air pressure recommended on
the decal located on the left door face.
Refer to Group 22—Tires And Wheels for the rec­
ommended method of tire/wheel rotation.

HEADLAMPS

MAINTENANCE SCHEDULE
Every six months check the headlamp beams to en­
sure that the headlamp beams are correctly posi­
tioned.

AIM
ADJUSTMENT
Refer to Group 8L—Lamps for headlamp aim ad­
justment procedures.

FRONT SUSPENSION
AND
AXLE
2 - 3

FRONT
WHEEL
ALIGNMENT

GENERAL
INFORMATION
Front wheel alignment involves
the
correct posi­
tioning
of the
tire contact patch
in
relation
to the

pavement.
The
positioning
is
accomplished through
the suspension
and
steering linkage adjustments.
An
alignment
is
essential
for
efficient steering
and
direc­
tional stability.
The
most important factors
of
front
end alignment
are
camber, caster
and toe
position. Routine inspection
of
the front
suspension
and
steering components
is a
good
preventative

maintenance practice.
Inspection
also
helps
to
ensure
safe operation
of the
vehicle.

• CAMBER
is the
number
of
degrees
the top of the

wheel
is
tilted either inward
or
outward.
An
excessive
negative camber angle will cause tread wear
at the in­
side
of
the tire.
An
excessive positive camber angle will
cause tread wear
at the
outside
of
the tire (Fig.
1),
• CASTER
is the
number
of
degrees
of
forward
or

rearward tilt
of the
steering knuckles. Forward tilt
provides
a
negative caster angle. Rearward tilt pro­ vides
a
positive caster angle
(Fig. 1).

• WHEEL
TOE
POSITION
is the
difference between
the leading
and
trailing inside edges
of the
front
tires (Fig.
1).
Incorrect wheel
toe
position
is the
most common cause
of
unstable steering
and
steering wheel off-center.
The
wheel
toe
position
is the
final
front wheel alignment adjustment. • STEERING AXIS INCLINATION ANGLE
is
mea­
sured
in
degrees
and is the
angle that
the
steering
knuckles
are
tilted (Fig. 1).
The
inclination angle
has

a fixed relationship with
the
camber angle. This will
not change except when
a
spindle
or
ball stud
is

damaged
or
bent.
The
angle
is not
adjustable
and the

damaged component(s) must
be
replaced
to
correct
mis-alignment.

CAUTION:
Do not
attempt to modify
any
suspension

or steering
component
by
heating
and
bending.

PRE-ALIGNMENT INSPECTION
Before starting
a
front wheel alignment,
the
follow­
ing inspection
and
necessary corrections must
be
completed.
(1)
Tires with
the
same recommended
air
pressure,

size,
and
tread wear. Refer
to
Group
22,
Wheels
and

Tires
for
diagnosis information. (2) Front wheel bearings
for
wear
or
adjustment.
(3) Ball studs
and
linkage pivot points, steering
gear
for
looseness, roughness, binding
or a
sticking
condition. Refer
to
Group
19,
Steering
for
additional information.
CASTER

POSITIVE CASTER
STEERING
WHEEL CENTER

i 0.5
CCW
0
5
CW

CCW
=
COUNTER CLOCKWISE
CW
-
CLOCKWISE
CAMBER

NEGATIVE CAMBER (SHOWN)
TOP
OF
WHEEL INBOARD
POSITIVE CAMBER
(NOT
SHOWN)
TOP
OF
WHEEL OUTBOARD
NOMINAL-PREFERRED

THE NOMINAL VALUE
IS

THE
PREFERRED
VALUE

LEFT/RIGHT
DIFFERENCE

THE VALUE
Of
THE LEFT SIDE
MINUS THE VALUE
OF
THE
RIGHT SIDE

EX.

If
FT CASTER
- +6 5

RIGHT
CASTER
»
+8.0

LEFT/RIGHT DIFFERENCE

65 8.0
=
1
5
TOE

NEGATIVE TOE (TOE
OUT)
B>A
POSITIVE TOE (TOE
IN) 6 FRONT
Of
VEHICLE
ft
THRUST
ANGLE

ANGLE
OF
REAR
AXLE RELATIVE
TO
VEHICLE CENTERUNE

(+)
AXLE POINTS LEFT
(-)
AXLE POINTS RIGHT

PRODUCTION
TOLERANCE
THE RANGE
Of
ACCEPTABLE

VALUES
AROUND THE NOMINAL

-
PREFERRED PRODUCTION
+6.5A7.5

PREFERRED:
+7.0

TOLERANCE:
0.5
J9302-61

Fig.
1
Wheel
Alignment
Measurements

2 - 4 FRONT SUSPENSION AND AXLE
•

I
FRONT END
|
|*?£E;
LOOSE
OR WORN
FRONT WHEEL
BEARINGS

LOOSE
C

SHOCKS

MOUNTir
WAR

SHOCK
A )RWORN

JSORBER

nIG
HARD-

E
OR
BSORBER
EXCiSSIVE
PLAY

STEERING

LINKAGE
LOOSE
OR WORN
FRONT WHEEL
BEARINGS

LOOSE
C

STEERINC
SHAFT
C
)RWORN

7
COLUMN
OUPLING
DIFFICULT

STEERING
LOOSE
OR WORN
WHEEL BEARINGS
TIRE/V
OUT OF
f
VHEEL
JA
LANCE
LOW OR UNEVEN
TIRE
AIR
PRESSURE

LO(
WHEEL B
DSE

EARINGS
LOW OR UNEVEN
TIRE AIR
PRESSURE
1vsnciEi

I
1
PULLS
TO I

I
|
ONE SIDE
j
LOOSE,
WORN
OR

GLAZED
P/S PUMP BELT LOW OR UNEVEN
TIRE PRESSURE
WHILE BR
REFE

BRAKES
AKING—

R
TO

SERVICE

LOOSE
STEERING
GEAR-TO-FRAME
RAIL BOLTS
LOOSE
STEERING

GEAR-TO-FRAME
RAIL BOLTS UNEVEN TIRE TREAD
WEAR,
OR
EX­

CESSIVELY
WORN TIRE TREAD
BROKEN
OR WEAK

REAR
SPRING LOW
POWER STEERING
FLUID
LEVEL
BROKEN
OR WEAK

REAR
SPRING
WORN

UPPER
SUSPENSION ARM BUSHINGS WORN TIE-

ROD
END

BALL
STUDS WORN TIE-

ROD
END

BALL
STUDS
SHOCK
ABSORBER

NOT FUNCTIONING
CORRECTLY
LACK
OF ASSIST
FROM POWER

STEERING
PUMP
LOOSE
OR WORN

SUSPENSION
BUSHINGS

WORN LOWER

SUSPENSION
ARM
PIVOT
BUSHINGS INCORRECT

STEERING
GEAR ADJUSTMENT
LOOSE
OR WORN

SUSPENSION
ARM
BUSHINGS
INCORRECT

STEERING
GEAR ADJUSTMENT
BALL
STUDS

REQUIRE

LUBRICATION INCORRECT FRONT
WHEEL ALIGNMENT (EITHER CASTER OR CAMBER)

LOOSE
LOWER

SUSPENSION
ARM
LOOSE
OR WORN

UPPER
SUSPENSION ARM BALL STUDS
LOOSE
OR WORN

SUSPENSION
ARM
BUSHINGS
STEERING
GEAR
LUBRICANT LEVEL LOW
WORN ISOLATOR

PAD
BETWEEN COIL
SPRING
AND

FRAME
BRACKET INCORRECT FRONT-
WHEEL ALIGNMENT (PARTICULARLY
CASTER)
INCORRECT FRONT
WHEEL ALIGNMENT INCORRECT

STEERING
GEAR ADJUSTMENT

STEERING
GEAR

MALFUNCTION
INCORRECT FRONT
WHEEL ALIGNMENT (PARTICULARLY
CASTER)

J9002-97
SUSPENSION AND STEERING
SYSTEM
DIAGNOSIS

•

FRONT
SUSPENSION
AND
AXLE
2 - 5 (4) Front wheels for excessive radial, lateral
runout and unbalance. Refer to Group 22, Wheels and Tires for diagnosis information.
(5) Suspension components for wear and noise. Check
components for correct torque. Refer to Groups 2 and 3, Suspension and Axle for additional information.

WHEEL
ALIGNMENT
MEASUREMENTS/ADJUSTMENTS
The front wheel alignment positions must be set to
the specified limits. This will prevent abnormal tire
tread wear. The equipment manufacturer's recommenda­
tions for use of their
equipment
should always
be followed. All
damaged
front suspension sys­
tem components
should
be replaced. Do not at­ tempt to straighten any
bent
component.

CAMBER AND CASTER-2WD VEHICLES Camber and caster angle adjustments involve repo­
sitioning the upper suspension arm cam adjustment
bolts (Fig. 2). Alignment adjustments are accom­
plished by loosening the nuts and changing the posi­
tion of the cam bolt.
(1) Remove all foreign material from the adjust­
ment bolt threads.
(2) Record the camber and caster measurements
before loosening the adjustment bolt nuts.
(3) The camber angle should be adjusted as near as
possible to the preferred angle. The caster should be
the same at both sides of the vehicle. Refer to the Specifications chart.
CAMBER AND CASTER—4WD VEHICLES For 4WD vehicles, the correct wheel camber (verti­
cal tilt) angle is factory preset at zero degree (0°).
Camber cannot be altered by adjustment.
CAUTION: Do not attempt to
adjust
the
camber
an­
gle by
heating
or bending the axle or any
suspen­

sion
component. If camber angle is
incorrect,
the
component(s)
causing
an
incorrect
angle must be replaced.
(1) It is important that the camber (vertical tilt)
angle be the same for both front wheels.
(2) The camber angle should be measured with ac­
curate wheel alignment equipment. The acceptable
range is -1° to +1°. Refer to the Specifications chart.
Road test the vehicle and observe the steering
wheel return-to-center position. Before road testing,
check
and
correct
the tire
inflation pressures. Inflate
both
of the front tires
with exactly the
same
pressure.
During the road test, make vehicle turns to both
the left and right. If the steering wheel returns to­
ward the center position unassisted, the caster angle is correct. However, if the steering wheel does not re­ turn toward the center position unassisted, an incor­
rect caster angle is probable.
(1) The caster angle is factory preset at positive
two degrees
(
+
2°).
The acceptable range is +1/2° to +
3
1/2°.
(2) The caster angle should be measured with ac­
curate wheel alignment equipment.
(3) Caster angle can be adjusted by installing ta­
pered shims between the front axle pads and the spring brackets. The caster angle should be adjusted
as near as possible to the preferred angle.
(4) Record the caster measurement before remov­
ing the original shims from the spring pads.
(5) The caster should be the same at both sides of
the vehicle. Refer to the Specifications chart.
RN1030

Fig.
2 Caster &
Camber
Adjustment Location—2WD
Vehicles

WHEEL TOE POSITION The wheel toe position adjustment should be the fi­
nal front wheel alignment adjustment. In all in­ stances, follow the equipment manufacturer's
recommended procedure.
(1) Secure the steering wheel with the front wheels
in the straight-ahead position. For vehicles equipped
with power steering, start the engine before straight­ ening the wheels.
With power steering, the engine should be op­
erating during the wheel toe position adjust­
ment.
(2) Loosen the tie rod adjustment sleeve clamp
bolts (Fig. 3).
(3) Adjust the wheel toe position by rotating the
tie rod adjustment sleeve (Fig. 3). Rotate each tie-rod end in the direction of
sleeve rotation during the adjustment (Fig. 3).
This will ensure that both tie-rod ends are at the center of their travel.
(4) If applicable, turn the ignition switch off.

•

FRONT
SUSPENSION
AND
AXLE
2 - 15 Ensure the shock absorber is positioned on the
stud with retainers correctly located (Fig. 2).
(2)
Position the inner retainers on the mounting

studs.

(3) Install the shock on the upper and lower stud
and install the outer retainers.
(4) Install the nuts on the frame bracket and axle
(Fig. 2). (5) Tighten the shock absorber upper and lower

nuts;
• Standard shock upper and lower nut to 75 Nnn (55
ft. lbs.) torque
• Air-adjustable shock upper nut to 75 N»m (55 ft. lbs.) torque, lower nut to 271 Nnn (200 ft. lbs.)
torque

CAUTION:
Vehicles
with
air
shocks MUST
maintain

a
minimum
pressure
of 10 to 15 psi (70 to 105 kPa). Operation below the specified minimum
pressures
may cause damage.

(6) Remove the supports and lower the vehicle.

LEAF
SPRINGS
REMOVAL
(1) Raise and support the frame until all weight is
removed from the front springs. (2) With the front tires in contact with the surface,
position support stands under the frame side rails. (3) Remove the nuts, lockwashers, U-bolts that at­
tach the spring to the axle shaft tubes (Fig. 3).
SPRING
BRACKET SPRING
BRACKET SPRING
SHACKLE
PLATE
FRONT
SPRING
AXLE
TUBE U-BOLT LEFT
SIDE

J9017-33

Fig.
3 Front
Suspension
(4) Remove the spring front eye pivot nut and bolt,
rear spring shackle nuts, shackle plates. Remove the spring from the vehicle (Fig. 3).
INSTALLATION

(1) Align the spring front eye with the bolt hole in
the frame bracket and install the pivot bolt and nut (Fig. 3). (2) Position the shackle plates at the spring rear
eye and frame rail bracket. Install the nuts (Fig. 3). (3) Tighten the shackle plate nuts and front pivot
bolt nut until all slack is taken up. (4) Position the spring on the axle tube with the
spring center bolt seated in locating hole in axle tube
pad (Fig. 3).
(5) Install the U-bolts, new lockwashers and nuts.
(6) Tighten the nuts snug against the spring
bracket.
(7) Remove the supports and lower the vehicle
with the weight being supported by the tires. (8) Tighten the spring nuts according to the follow­
ing specifications:
• Model 44 Axle: U-bolt/Stud nuts - 115 Nnn (85 ft. lbs.) torque
Front pivot bolt/nut — 135 Nnn (100 ft. lbs.) torque
Rear shackle bolt/nut — 81 Nnn (60 ft. lbs.) torque
• Model 60 Axle: U-bolt nuts - 129 Nnn (95 ft. lbs.) torque Front pivot bolt/nut - 135 Nnn (100 ft. lbs.) torque
Rear shackle bolt/nut - 108 Nnn (80 ft. lbs.)
torque

SPRING LEAF-REPLACEMENT
If a spring has acquired a set (lost significant
height), it should be replaced. (1) Remove the spring from the vehicle. If neces­
sary, refer to the removal procedure. (2) Remove the spring leaf alignment clips.
(3) Clamp the spring in a vise. Remove the nut
and center bolt (Fig. 4).
SPRING

CENTER
RATCHET
AND

SOCKET

WRENCH

Fig.
4 Leaf
Spring
Disassembly
(4) Insert a long drift or punch into the center bolt
hole and slowly release the vise jaws.

•

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
- 4
BRAKES

• (3) During road test, make normal and firm brake
stops in 25-40 mph (40-64 Km/h) range. Note faulty
brake operation such as pull, grab, drag, noise, low
pedal, etc.
(4) Inspect suspect brake components and refer to
problem diagnosis information for causes of various
brake conditions.

COMPONENT
INSPECTION
Fluid leak points and dragging brake units can usu­
ally be located without removing any components. The
area around a leak point will be wet with fluid. The
components at a dragging brake unit (wheel, tire, rotor)
will be quite warm or hot to the touch.
Other brake problem conditions will require compo­
nent removal for proper inspection. Raise the vehicle and remove the necessary wheels for better visual ac­

cess.

DIAGNOSING BRAKE
PROBLEMS

PEDAL FALLS
AWAY
A
brake pedal that falls away under steady foot
pressure is the result of a system leak. The leak
point could be at a brakeline, fitting, hose, or caliper. Internal leakage in the master cylinder caused by
worn or damaged piston cups, may also be the prob­ lem cause.
If leakage is severe, fluid will be evident at or around
the leaking component. However, internal leakage in
the master cylinder may not be physically evident. Re­ fer to the cylinder test procedure in this section.

LOW PEDAL
If a low pedal is experienced, pump the pedal sev­
eral times. If the pedal comes back up, worn lining
and worn rotors or drums are the likely causes.
A decrease in fluid level in the master cylinder res­
ervoirs may only be the result of normal lining wear.
Fluid level can be expected to decrease in proportion to wear. It is a result of the outward movement of
caliper and wheel cylinder pistons to compensate for
normal wear. Top off the reservoir fluid level and
check brake operation to verify proper brake action.
SPONGY PEDAL. A spongy pedal is most often caused by air in the sys­
tem. Thin brake drums or substandard brake lines and
hoses can also cause a spongy pedal. The proper course
of action is to bleed the system and replace thin drums and suspect quality brake lines and hoses.

HARD PEDAL
OR
HIGH
PEDAL
EFFORT
A hard pedal or high pedal effort may be due to
lining that is water soaked, contaminated, glazed, or
badly worn. The power booster or check valve could also be faulty. On diesel engine models, high pedal effort may be
the result of a low vacuum condition. If the booster and check valve are OK, the problem may be related
to a vacuum pump hose, hose connection, hose fit­
ting, pump diaphragm, or drive gear. Vacuum pump output can be checked with a standard vacuum
gauge. Vacuum output should range from 8.5 to 25 inches vacuum. If vacuum pump output is within

limits,
check the power booster and check valve as
described in this section.

BRAKE DRAG
Brake drag occurs when the lining is in constant
contact with the rotor or drum. Drag can occur at
one wheel, all wheels, fronts only, or rears only. It is a product of incomplete brakeshoe release. Drag can
be minor or severe enough to overheat the linings,
rotors and drums.
Brake drag can also effect fuel economy. If undetec­
ted, minor brake drag can be misdiagnosed as an en­ gine or transmission/torque converter problem.
Minor drag will usually cause slight surface charring
of the lining. It can also generate hard spots in rotors and drums from the overheat-cool down process. In most

cases,
the rotors, drums, wheels and tires are quite
warm to the touch after the vehicle is stopped.
Severe drag can char the brake lining all the way
through. It can also distort and score rotors and drums to the point of replacement. The wheels, tires and brake components will be extremely hot. In se­
vere cases, the lining may generate smoke as it chars
from overheating.
Some common causes of brake drag are:
• seized or improperly adjusted parking brake cables
• loose/worn wheel bearing
• seized caliper or wheel cylinder piston
• caliper binding on corroded bushings or rusted
slide surfaces
• loose caliper mounting bracket
• drum brakeshoes binding on worn or damaged sup­
port plates
• misassembled components. If brake drag occurs at all wheels, the problem may
be related to a blocked master cylinder return port, or faulty power booster that binds and does not release.

BRAKE FADE
Brake fade is a product of overheating caused by
brake drag. However, brake overheating and subse­ quent fade can also be caused by riding the brake
pedal, making repeated high deceleration stops in a short time span, or constant braking on steep moun­
tain roads. Refer to the Brake Drag information in
this section for additional causes.

PEDAL
PULSA
TION
Pedal pulsation is caused by components that are
loose, out of round, or worn beyond tolerance limits.