torque DODGE RAM 1500 1998 2.G Workshop Manual
[x] Cancel search | Manufacturer: DODGE, Model Year: 1998, Model line: RAM 1500, Model: DODGE RAM 1500 1998 2.GPages: 2627
Page 2296 of 2627

BODY
TABLE OF CONTENTS
page page
BODY
WARNING
SAFETY PRECAUTIONS AND WARNINGS . . . 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - WATER LEAKS . 1
DIAGNOSIS AND TESTING - WIND NOISE . . . 2
STANDARD PROCEDURE
STANDARD PROCEDURE - BODY
LUBRICATION.........................3
STANDARD PROCEDURE - HEAT STAKING . . 3
STANDARD PROCEDURE - PLASTIC BODY
PANEL REPAIR........................3
STANDARD PROCEDURE - BUZZ, SQUEAK
& RATTLE...........................11
SPECIFICATIONS - TORQUE..............12SPECIAL TOOLS
BODY..............................14
TAILGATE..............................15
DOOR - FRONT.........................18
DOORS - REAR.........................28
EXTERIOR.............................36
HOOD.................................46
INSTRUMENT PANEL.....................49
INTERIOR..............................62
PAINT.................................73
SEATS................................75
STATIONARY GLASS.....................86
WEATHERSTRIP/SEALS...................91
BODY STRUCTURE......................95
BODY
WARNING
SAFETY PRECAUTIONS AND WARNINGS
WARNING: USE AN OSHA APPROVED BREATHING
FILTER WHEN SPRAYING PAINT OR SOLVENTS IN
A CONFINED AREA. PERSONAL INJURY CAN
RESULT.
²AVOID PROLONGED SKIN CONTACT WITH
PETROLEUM OR ALCOHOL ± BASED CLEANING
SOLVENTS. PERSONAL INJURY CAN RESULT.
²DO NOT STAND UNDER A HOISTED VEHICLE
THAT IS NOT PROPERLY SUPPORTED ON SAFETY
STANDS. PERSONAL INJURY CAN RESULT.
CAUTION: When holes must be drilled or punched
in an inner body panel, verify depth of space to the
outer body panel, electrical wiring, or other compo-
nents. Damage to vehicle can result.
²Do not weld exterior panels unless combustible
material on the interior of vehicle is removed from
the repair area. Fire or hazardous conditions, can
result.
²Always have a fire extinguisher ready for use
when welding.
²Disconnect the negative (-) cable clamp from
the battery when servicing electrical components
that are live when the ignition is OFF. Damage to
electrical system can result.²Do not use abrasive chemicals or compounds
on painted surfaces. Damage to finish can result.
²Do not use harsh alkaline based cleaning sol-
vents on painted or upholstered surfaces. Damage
to finish or color can result.
²Do not hammer or pound on plastic trim panel
when servicing interior trim. Plastic panels can
break.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - WATER LEAKS
Water leaks can be caused by poor sealing,
improper body component alignment, body seam
porosity, missing plugs, or blocked drain holes. Cen-
trifugal and gravitational force can cause water to
drip from a location away from the actual leak point,
making leak detection difficult. All body sealing
points should be water tight in normal wet-driving
conditions. Water flowing downward from the front of
the vehicle should not enter the passenger or luggage
compartment. Moving sealing surfaces will not
always seal water tight under all conditions. At
times, side glass or door seals will allow water to
enter the passenger compartment during high pres-
sure washing or hard driving rain (severe) condi-
tions. Overcompensating on door or glass
adjustments to stop a water leak that occurs under
severe conditions can cause premature seal wear and
excessive closing or latching effort. After completing
a repair, water test vehicle to verify leak has stopped
before returning vehicle to use.
DRBODY 23 - 1
Page 2307 of 2627

SPECIFICATIONS - TORQUE
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A-pillar trim/grab handle bolts 6 Ð 55
Body Isolator/cab bolts 81 60 Ð
Cargo box bolts 108 80 Ð
Cargo box tie down/cleat bolts 34 25 Ð
Center seat assembly nuts*25 18 Ð
Center seat cushion/hinge bolts*20 15 Ð
Center seat back hinge to storage bin bolts*25 18 Ð
Center seat back free pivot hinge bolt*25 18 Ð
Center seat back inertia hinge pivot bolt*10 Ð 89
Center seat inertia hinge to seat back bolts*25 18 Ð
Fender bolts - front lower 9 Ð 80
Fender bolts - lower inside 17 13 Ð
Fender to hinge support bolts 11 8 Ð
Fender to upper fender rail bolts 9 Ð 80
Footmans loop bolts 12 9 Ð
Front center seat nuts*25 18 Ð
Front door glass lift plate nuts 10 Ð 89
Front door hinge to a-pillar nuts 28 21 Ð
Front door hinge to door nuts/bolts 28 21 Ð
Front door inside handle bolt 9 Ð 80
Front door latch adjustment screw 3 Ð 30
Front door latch assembly bolts 10 Ð 89
Front door latch striker bolts 28 21 Ð
Front door latch striker bolts 28 21 Ð
Front door regulator bolts 10 Ð 89
Front door regulator stabilizer nuts 10 Ð 89
Front door remote handle actuator nuts 10 Ð 89
Front door run channel screws 10 Ð 89
Front seat assembly front bolts*28 30 Ð
Front seat assembly rear bolts*40 30 Ð
Front seat track nuts*25 18 Ð
Fuel fill door bolts 9 Ð 80
Hood hinge to fender rail bolts 20 15 Ð
Hood latch bolts 11 8 Ð
Hood latch striker/safety catch bolts 11 8 Ð
Hood hinge to hood nuts 23 17 Ð
Instrument panel center bracket bolts 12 9 Ð
Instrument panel column support bolts 14 10 Ð
Instrument panel side mounting bolts 12 9 Ð
23 - 12 BODYDR
BODY (Continued)
Page 2314 of 2627

ADJUSTMENTS
ADJUSTMENT
NOTE: For vehicles with four doors, it is recom-
mended that you adjust the rear door before adjust-
ing the front door. (Refer to 23 - BODY/DOORS -
REAR/DOOR - ADJUSTMENTS)
²Door adjustment measurements should be
taken from stationary or welded body panels like
the roof, rocker or quarter panels.
²During adjustment procedures, it is recom-
mended that all the hinge fasteners be loosened
except for the upper most fasteners. Adjustments
can be made using the upper bolts to hold the door
with final torque of the fasteners occurring after
correct door positioning is achieved.
²A suitable body sealant should be used when
removing or moving the hinges.
FORE/AFT
NOTE: Fore/aft (lateral) door adjustment is done by
loosening the hinge to the hinge pillar fasteners
one hinge at a time and moving the door to the cor-
rect position.
(1) Support the door with a suitable lifting device.
(2)
Loosen the hinge to hinge pillar fasteners. (Refer
to 23 - BODY/DOOR - FRONT/HINGE - REMOVAL)
(3) Adjust the door to the correct position. (Refer
to 23 - BODY/BODY STRUCTURE/GAP AND
FLUSH - SPECIFICATIONS)(4) Tighten the hinge pillar fasteners to 28 N´m
(21 ft. lbs.).
UP/DOWN
NOTE: Up/down door adjustment is done by loosen-
ing either the hinge to the hinge pillar fasteners or
the hinge to door fasteners and moving the door to
the correct position.
NOTE: When adjustment of the door requires the
loosening of the door to hinge fasteners, it will be
necessary to separate the epoxy bonded washers
with a chisel or other suitable tool.
NOTE: When the up/down adjustments are done
correctly, the top of the door is positioned over
flush to the roof. (Refer to 23 - BODY/BODY STRUC-
TURE/GAP AND FLUSH - SPECIFICATIONS)
(1) Support the door with a suitable lifting device.
(2) Loosen the latch striker bolts. (Refer to 23 -
BODY/DOOR - FRONT/LATCH STRIKER -
REMOVAL)
(3) Loosen the hinge to door fasteners (Refer to 23
- BODY/DOOR - FRONT/DOOR - REMOVAL) or
loosen the hinge to hinge pillar fasteners (Refer to 23
- BODY/DOOR - FRONT/HINGE - REMOVAL).
(4) Adjust the door to the correct position. (Refer
to 23 - BODY/BODY STRUCTURE/GAP AND
FLUSH - SPECIFICATIONS)
(5) Tighten the hinge pillar fasteners or the door
to hinges fasteners to 28 N´m (21 ft. lbs.).
(6) Tighten the latch striker bolts. (Refer to 23 -
BODY/DOOR - FRONT/LATCH STRIKER - INSTAL-
LATION)
IN/OUT
NOTE: In/out door adjustment is done by loosening
the hinge to door fasteners one hinge at a time and
moving the door to the correct position.
NOTE: When adjustment of the door requires the
loosening of the door to hinge fasteners, it will be
necessary to separate the epoxy bonded washers
with a chisel or other suitable tool.
(1) Support the door with a suitable lifting device.
(2) Loosen the latch striker bolts. (Refer to 23 -
BODY/DOOR - FRONT/LATCH STRIKER -
REMOVAL)
(3) Loosen the hinge to door fasteners. (Refer to 23
- BODY/DOOR - FRONT/DOOR - REMOVAL)
Fig. 1 FRONT DOOR
1 - NUTS (2)
2 - UPPER HINGE
3 - STUDS
4 - FRONT DOOR
5 - WIRE HARNESS
6 - LOWER HINGE
7 - ELECTRICAL CONNECTORS (2)
8 - BOLTS (2)
DRDOOR - FRONT 23 - 19
DOOR (Continued)
Page 2323 of 2627

DOORS - REAR
TABLE OF CONTENTS
page page
DOOR
REMOVAL.............................28
INSTALLATION.........................28
ADJUSTMENTS
ADJUSTMENT........................28
DOOR GLASS
REMOVAL.............................30
INSTALLATION.........................30
EXTERIOR HANDLE
REMOVAL.............................30
INSTALLATION.........................30
GLASS RUN CHANNEL
REMOVAL.............................30
INSTALLATION.........................31
HINGE
REMOVAL.............................31
INSTALLATION.........................31
INSIDE HANDLE ACTUATOR
REMOVAL.............................31
INSTALLATION.........................32
LATCH
REMOVAL.............................32INSTALLATION.........................32
ADJUSTMENTS
ADJUSTMENT........................33
LATCH STRIKER
REMOVAL.............................33
INSTALLATION.........................33
ADJUSTMENTS
ADJUSTMENT........................33
TRIM PANEL
REMOVAL.............................33
INSTALLATION.........................33
WATERDAM
REMOVAL.............................34
INSTALLATION.........................34
WINDOW REGULATOR - POWER
REMOVAL.............................34
INSTALLATION.........................34
WINDOW REGULATOR - MANUAL
REMOVAL.............................35
INSTALLATION.........................35
DOOR
REMOVAL
(1) Disconnect the door wire harness electrical con-
nector at the b-pillar. (Fig. 1)
(2) Using a grease pencil or equivalent, mark the
outline of the door hinges on the door to aid in instal-
lation.
(3) Support the door with a suitable lifting device.
NOTE: The epoxy bonded washers should not be
seperated from the hinge. If the washers are
removed the door may have to be re-adjusted.
(4) Remove the nuts and bolts attaching the door
hinges to the door.
INSTALLATION
(1) Support the door with a suitable lifting device
and install the door onto the hinges.
(2) Install the bolts, nuts and washers, if there
were removed previously, and tighten to 28 N´m (21
ft. lbs.).
(3) Connect the electrical connector.(4) Adjust the door as necessary. (Refer to 23 -
BODY/DOORS - REAR/DOOR - ADJUSTMENTS)
ADJUSTMENTS
ADJUSTMENT
NOTE: For vehicles equipped with four doors, it is
recommended that you adjust the rear door before
adjusting the front door.
²Door adjustment measurements should be
taken from stationary or welded body panels like
the roof, rocker or quarter panels.
²During adjustment procedures, it is recom-
mended that all the hinge fasteners be loosened
except for the upper most fasteners. Adjustments
can be made using the upper fasteners to hold the
door with final torque of the fasteners occurring
after correct door positioning is achieved.
23 - 28 DOORS - REARDR
Page 2365 of 2627

INSTALLATION
INSTALLATION
(1) Position the mirror base at the bracket and
slide it downward onto the support bracket (Fig. 18).
(2) Tighten the setscrew 1 N´m (15 in. lbs.) torque.
(3) If equipped, connect mirror harness connector.
INSTALLATION - REAR VIEW MIRROR
SUPPORT BRACKET
(1) Mark the position for the mirror bracket on the
outside of the windshield glass with a wax pencil.
(2) Clean the bracket contact area on the glass.
Use a mild powdered cleanser on a cloth saturated
with isopropyl (rubbing) alcohol. Finally, clean the
glass with a paper towel dampened with alcohol.
(3) Sand the surface on the support bracket with
fine grit-sandpaper. Wipe the bracket surface clean
with a paper towel.
(4) Apply accelerator to the surface on the bracket
according to the following instructions:
(a) Crush the vial to saturate the felt applicator.
(b) Remove the paper sleeve.
(c) Apply accelerator to the contact surface on
the bracket.
(d) Allow the accelerator to dry for five minutes.
(e) Do not touch the bracket contact surface
after the accelerator has been applied.
(5) Apply adhesive accelerator to the bracket con-
tact surface on the windshield glass. Allow the accel-
erator to dry for one minute. Do not touch the glass
contact surface after the accelerator has been
applied.
(6) Install the bracket according to the following
instructions:(a) Apply one drop of adhesive at the center of
the bracket contact-surface on the windshield
glass.
(b) Apply an even coat of adhesive to the contact
surface on the bracket.
(c) Align the bracket with the marked position
on the windshield glass.
(d) Press and hold the bracket in place for at
least one minute.
NOTE: Verify that the mirror support bracket is cor-
rectly aligned, because the adhesive will cure rapidly.
(7) Allow the adhesive to cure for 8-10 minutes.
Remove any excess adhesive with an alcohol-damp-
ened cloth.
(8) Allow the adhesive to cure for an additional
8-10 minutes before installing the mirror.
SUN VISOR
REMOVAL
(1) Remove the screws at the visor pivot and
remove the visor.
INSTALLATION
(1) Install the visor and install the screws at the
visor pivots.
SUN VISOR SUPPORT
REMOVAL
(1) Using a trim stick C-4755 or equivalent, pry
down the release clip and remove the hook. (Fig. 19)
Fig. 18 REAR VIEW MIRROR
1 - CONNECTOR
2 - SCREW
3 - REAR VIEW MIRROR
4 - SUPPORT BUTTON
5 - WINDSHIELD
Fig. 19 VISOR SUPPORT
1 - VISOR SUPPORT
2 - HEADLINER
3 - RELEASE CLIP
23 - 70 INTERIORDR
REAR VIEW MIRROR (Continued)
Page 2494 of 2627

²Faulty A/C-heater control.
²Faulty related wiring harness or connectors.
²Improper engine coolant temperature.
SPECIFICATIONS - A/C SYSTEM
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood Specifica-
tion Label.
A/C SYSTEM SPECIFICATION CHART
Item Description Notes
Compressor Saden SD-7
(5.9L engine)SP-15 PAG oil
Denso 10S17
(3.7L/4.7L/5.7L
engines)ND-8 PAG oil
Freeze±up
ControlEvaporator
Temperature
SensorEvaporator coil
mounted
High psi Control A/C pressure
transducerDischarge line
mounted
Compressor
Clutch Coil
Draw2 - 3.9 amps @
12V 0.5V @
21É C (70É F)5.9L engine
2.2 amps @
12V 0.5V @
21É C (70É F)3.7L/4.7L/5.7L
engines
Compressor
Clutch Air Gap0.41 - 0.79 mm
(0.016 - 0.031
in.)5.9L engine
0.35 - 0.65 mm
(0.013 - 0.025
in.)3.7L/4.7L/5.7L
engines
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft Nut 15-20 11-15 ±
A/C Compressor Bolt-Inner
Front-3.7L,4.7L40 30 ±
A/C Compressor Bolt-Inner
Rear-3.7L,4.7L55 41 ±
A/C Compressor Rear Bolt-
3.7L,4.7L55 41 ±
A/C Compressor Lower Bolts-5.7L 40 30 ±
A/C Compressor Rear Bolt-5.7L 55 41 ±
A/C Compressor Bolts-5.9L Diesel 24 17 ±
A/C Compressor Clutch Coil Wire
Retainer Screw2.2 ± 20
A/C-Heater Control Screws 2.2 ± 20
Accumulator Bracket Bolts 4.5 ± 40
Blower Motor Screws 2.2 ± 20
Blower Motor Resistor Block
Screws2.2 ± 20
Center Distribution Duct Screws 2.2 ± 20
DRHEATING & AIR CONDITIONING 24 - 7
HEATING & AIR CONDITIONING (Continued)
Page 2497 of 2627

and coil are the only serviced parts on the compres-
sor.
A/C compressor clutch engagement is controlled by
several components: the A/C-heater control, A/C pres-
sure transducer, A/C compressor clutch relay, evapo-
rator temperature sensor and the powertrain control
module (PCM). The PCM may delay compressor
clutch engagement for up to thirty seconds (Refer to
8 - ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the A/C-heater controls in any A/C mode,
and the blower motor switch in the lowest speed
position, start the engine and run it at normal idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of thecompressor clutch circuit and PCM control. The fol-
lowing components must be checked and repaired as
required before you can complete testing of the clutch
coil:
²Fuses in the junction block and the power distri-
bution center (PDC)
²A/C-heater control
²A/C compressor clutch relay
²A/C pressure transducer
²Evaporator temperature sensor
²Powertrain control module (PCM)
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is within
specifications with the electrical system voltage at
11.5 to 12.5 volts (Refer to 24 - HEATING & AIR
CONDITIONING - SPECIFICATIONS). This should
only be checked with the work area temperature at
21É C (70É F). If system voltage is more than 12.5
volts, add electrical loads by turning on electrical
accessories until the system voltage drops below 12.5
volts.
(a) If the clutch coil current reading is above
specifications, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C-heater control to the
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
to 2000 rpm. This procedure (burnishing) will seat
the opposing friction surfaces and provide a higher
compressor clutch torque capability.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, rotor, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the serpentine drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(3) Disconnect the compressor clutch coil wire har-
ness connector.
(4) Remove the bolts that secure the compressor to
the mounting bracket.
(5) Remove the compressor from the mounting
bracket. Support the compressor in the engine com-
partment while servicing the clutch.
Fig. 1 Compressor Clutch - Typical
1 - CLUTCH PLATE
2 - SHAFT KEY (not used on KJ)
3 - ROTOR
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 10 CONTROLSDR
A/C COMPRESSOR CLUTCH/COIL (Continued)
Page 2564 of 2627

Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel posi-
tion. The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-
phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is con-
trolled in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5º H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would even-
tually stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate rep-
resentative of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (cur-
rently set at .040º orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicatedby a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. This can increase vehicle emissions
and deteriorate engine performance, driveability and
fuel economy.
The catalyst monitor uses dual oxygen sensors
(O2S's) to monitor the efficiency of the converter. The
dual O2S's sensor strategy is based on the fact that
as a catalyst deteriorates, its oxygen storage capacity
and its efficiency are both reduced. By monitoring
the oxygen storage capacity of a catalyst, its effi-
ciency can be indirectly calculated. The upstream
DREMISSIONS CONTROL 25 - 3
EMISSIONS CONTROL (Continued)
Page 2571 of 2627

EVAPORATIVE EMISSIONS
TABLE OF CONTENTS
page page
EVAPORATIVE EMISSIONS
DESCRIPTION - EVAP SYSTEM............10
SPECIFICATIONS
TORQUE - EVAP SYSTEM...............11
CCV HOSE
DESCRIPTION - 8.0L V-10................12
OPERATION - 8.0L V-10..................12
EVAP/PURGE SOLENOID
DESCRIPTION.........................12
OPERATION...........................12
REMOVAL.............................12
INSTALLATION.........................12
FUEL FILLER CAP
DESCRIPTION.........................13
OPERATION...........................13
REMOVAL
REMOVAL/INSTALLATION...............13
LEAK DETECTION PUMP
DESCRIPTION.........................13
OPERATION...........................14
REMOVAL.............................16
INSTALLATION.........................16ORVR
DESCRIPTION.........................17
OPERATION...........................17
P C V VA LV E
DESCRIPTION.........................17
OPERATION...........................19
DIAGNOSIS AND TESTING - PCV VALVE -
3.7L V-6/ 4.7L V-8......................20
REMOVAL.............................21
INSTALLATION.........................21
VACUUM LINES
DESCRIPTION.........................22
VAPOR CANISTER
DESCRIPTION.........................22
OPERATION...........................22
REMOVAL.............................22
INSTALLATION.........................22
NATURAL VAC LEAK DETECTION ASSY
DESCRIPTION.........................23
OPERATION...........................23
REMOVAL.............................24
INSTALLATION.........................25
EVAPORATIVE EMISSIONS
DESCRIPTION - EVAP SYSTEM
The evaporation control system prevents the emis-
sion of fuel tank vapors into the atmosphere. When
fuel evaporates in the fuel tank, the vapors pass
through vent hoses or tubes into the two charcoal
filled evaporative canisters. The canisters tempo-
rarily hold the vapors. The Powertrain Control Mod-
ule (PCM) allows intake manifold vacuum to draw
vapors into the combustion chambers during certain
operating conditions.
All gasoline powered engines use a duty cycle
purge system. The PCM controls vapor flow by oper-
ating the duty cycle EVAP purge solenoid. Refer to
Duty Cycle EVAP Canister Purge Solenoid for addi-
tional information.When equipped with certain emissions packages, a
Leak Detection Pump (LDP) will be used as part of
the evaporative system. This pump is used as a part
of OBD II requirements. Refer to Leak Detection
Pump for additional information. Other emissions
packages will use a Natural Vacuum Leak Detection
(NVLD) system in place of the LDP. Refer to NVLD
for additional information.
NOTE: The hoses used in this system are specially
manufactured. If replacement becomes necessary, it
is important to use only fuel resistant hose.
Certain EVAP system components can be found in
(Fig. 1).
25 - 10 EVAPORATIVE EMISSIONSDR
Page 2572 of 2627

SPECIFICATIONS
TORQUE - EVAP SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
EVAP Canister Mounting
Nuts11 -95
EVAP Canister Mounting
Bracket-to-Frame Bolts14 10125
Leak Detection Pump
Mounting Bolts11 - 9 5
Leak Detection Pump
Filter Mounting Bolt11 - 9 5
Fig. 1 FUEL DELIVERY COMPONENTS
1 - FUEL TANK 8 - LDP FRESH AIR FILTER
2 - CHECK VALVE 9 - LEAK DETECTION PUMP
3 - LIQUID EXPANSION CHAMBER 10 - EVAP CANISTERS (2)
4 - FUEL FILTER / FUEL PRESSURE REGULATOR 11 - FUEL TANK STRAPS (2)
5 - QUICK-CONNECT FITTING AND FUEL LINE (TO ENGINE) 12 - CHECK VALVE
6 - EVAP LINE CONNECTION 13 - FUEL PUMP MODULE LOCK RING
7 - LEAK DETECTION PUMP FRESH AIR LINE 14 - FUEL PUMP MODULE
DREVAPORATIVE EMISSIONS 25 - 11
EVAPORATIVE EMISSIONS (Continued)