1998 DODGE RAM 1500 Vacuum lines

(13) Measure the low/reverse clutch pack clearance
and adjust as necessary. The correct clutch clearance
is 1.00-1.74 mm (0.039-0.075 in.).
(14) Install the overrunning clutch into the low/re-
verse clutch retainer making sure that the index
splines are aligned with the retainer.
(15) Install the overrunning clutch inner snap-
ring.
OIL PUMP
DESCRIPTION
The oil pump (Fig. 96) is located at the front of the
transmission inside the bell housing and behind the
transmission front cover. The oil pump consists of
two independent pumps (Fig. 97), a number of valves
(Fig. 98), a front seal (Fig. 99), and a bolt on reaction
shaft. The converter clutch switch and regulator
valves, pressure regulator valve, and converter pres-
sure limit valve are all located in the oil pump valve
body.
OPERATION
As the torque converter rotates, the converter hub
rotates the oil pump drive gear. As the drive gear
rotates both driven gears, a vacuum is created when
the gear teeth come out of mesh. This suction draws
fluid through the pump inlet from the oil pan. As the
gear teeth come back into mesh, pressurized fluid is
forced into the pump outlet and to the oil pump
valves.
At low speeds, both sides of the pump supply fluid
to the transmission. As the speed of the torque con-verter increases, the flow from both sides increases
until the flow from the primary side alone is suffi-
cient to meet system demands. At this point, the
check valve located between the two pumps closes.
The secondary side is shut down and the primary
side supplies all the fluid to the transmission.
CONVERTER CLUTCH SWITCH VALVE
The converter clutch switch valve is used to control
the hydraulic pressure supplied to the front (OFF)
side of the torque converter clutch.
Fig. 96 Oil Pump
1 - OIL PUMP TO CASE BOLT (6)
2 - OIL PUMP
Fig. 97 Oil Pump Gears
1 - PUMP HOUSING
2 - DRIVE GEAR
3 - DRIVEN GEARS
Fig. 98 Oil Pump Valves
1 - TORQUE CONVERTER CLUTCH ACCUMULATOR VALVE
2 - TORQUE CONVERTER CLUTCH CONTROL VALVE
3 - TORQUE CONVERTER CLUTCH SWITCH VALVE
4 - PUMP VALVE BODY
5 - PRESSURE REGULATOR VALVE
6 - TORQUE CONVERTER CLUTCH LIMIT VALVE
21 - 386 AUTOMATIC TRANSMISSION - 45RFE/545RFEDR
LOW/REVERSE CLUTCH (Continued)

Condition Possible Causes Correction
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid, Suction, and Discharge Line in this
group. Inspect the refrigerant lines for kinks, tight
bends or improper routing. Correct the routing or
replace the refrigerant line, if required.
2. Restricted refrigerant flow
through the fixed orifice tube.2. See A/C Orifice Tube in this group. Replace
the liquid line, if required.
3. Restricted refrigerant flow
through the condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
DIAGNOSIS AND TESTING - HEATER
PERFORMANCE TEST
Review Safety Warnings and Cautions before per-
forming this procedure (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - WARNING) and
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - CAUTION).
Check the coolant level, drive belt tension, vacuum
line connections, radiator air flow and fan operation.
Start engine and allow to warm up to normal tem-
perature.
WARNING: DO NOT REMOVE RADIATOR CAP
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
RESULT.
If vehicle has been run recently, wait 15 minutes
before removing cap. Place a rag over the cap andturn it to the first safety stop. Allow pressure to
escape through the overflow tube. When the system
stabilizes, remove the cap completely.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two heater hoses. With the engine idling at normal
operating temperature, set the temperature control
to maximum heat, the mode control to the floor posi-
tion, and the blower in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged from the floor outlets. Com-
pare the test thermometer reading to the Tempera-
ture Reference chart.
TEMPERATURE REFERENCE CHART
Ambient Air Temperature15.5É C
(60É F)21.1É C
(70É F)26.6É C
(80É F)32.2É C
(90É F)
Minimum Air Temperature at
Floor Outlet62.2É C
(144É F)63.8É C
(147É F)65.5É C
(150É F)67.2É C
(153É F)
Both of the heater hoses should be HOT to the
touch (coolant return hose should be slightly cooler
than the supply hose). If the coolant return hose is
much cooler than the supply hose, locate and repair
the engine coolant flow obstruction in the heater sys-
tem. If both heater hoses are cool to the touch,
inspect the engine cooling system (Refer to 7 -
COOLING - DIAGNOSIS AND TESTING).
OBSTRUCTED COOLANT FLOW Possible loca-
tions or causes of obstructed coolant flow are as fol-
lows:
²Pinched or kinked heater hoses.
²Improper heater hose routing.
²Plugged heater hoses or supply and return ports
at the cooling system connections.
²Plugged heater core.If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is insuffi-
cient, a mechanical problem may exist.
MECHANICAL PROBLEMS Possible causes of
insufficient heat due to mechanical problems are as
follows:
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend door not functioning properly.
TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on the
A/C-heater control, the following could require ser-
vice:
²Blend door binding.
²Faulty blend door motor.
24 - 6 HEATING & AIR CONDITIONINGDR
HEATING & AIR CONDITIONING (Continued)

DIAGNOSIS AND TESTING - REFRIGERANT
SYSTEM LEAKS
WARNING: R-134a SERVICE EQUIPMENT OR VEHI-
CLE A/C SYSTEM SHOULD NOT BE PRESSURE
TESTED OR LEAK TESTED WITH COMPRESSED
AIR. MIXTURE OF AIR and R-134a CAN BE COM-
BUSTIBLE AT ELEVATED PRESSURES. THESE MIX-
TURES ARE POTENTIALLY DANGEROUS AND MAY
RESULT IN FIRE OR EXPLOSION CAUSING INJURY
OR PROPERTY DAMAGE.
AVOID BREATHING A/C REFRIGERANT AND LUBRI-
CANT VAPOR OR MIST. EXPOSURE MAY IRRITATE
EYES, NOSE AND THROAT. USE ONLY APPROVED
SERVICE EQUIPMENT MEETING SAE REQUIRE-
MENTS TO DISCHARGE R-134a SYSTEM. IF ACCI-
DENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE WORK AREA BEFORE RESUMING SER-
VICE.
NOTE: The refrigerant system does come from the
factory with a yellow tracer dye already installed to
aid in detection of leaks.
If the A/C system is not cooling properly, determine
if the refrigerant system is fully charged with
R-134a. This is accomplished by performing a system
Charge Level-Check or Fill. If while performing this
test A/C liquid line pressure is less than 345 kPa (50
psi) proceed to System Empty procedure. If liquid
line pressure is greater than 345 kPa (50 psi) proceed
to System Low procedure. If the refrigerant system is
empty or low in refrigerant charge, a leak at any line
fitting or component seal is likely. A review of the fit-
tings, lines and components for oily residue is an
indication of the leak location. To detect a leak in the
refrigerant system, perform one of the following pro-
cedures as indicated by the symptoms.
SYSTEM EMPTY
(1) Evacuate the refrigerant system to the lowest
degree of vacuum possible (approx. 28 in Hg.). Deter-
mine if the system holds a vacuum for 15 minutes. If
vacuum is held, a leak is probably not present. If sys-
tem will not maintain vacuum level, proceed with
this procedure.(2) Prepare a 0.284 Kg. (10 oz.) refrigerant charge
to be injected into the system.
(3) Connect and dispense 0.284 Kg. (10 oz.) of
refrigerant into the evacuated refrigerant system.
(4) Proceed to Step 2 of System Low procedure.
SYSTEM LOW
(1) Determine if there is any (R-134a) refrigerant
in the system.
(2) Position the vehicle in a wind free work area.
This will aid in detecting small leaks.
(3) Bring the refrigerant system up to operating
temperature and pressure. This is done by allowing
the engine to run for five minutes with the system
set to the following:
²Transmission in Park or Neutral with parking
brake set
²Engine idling at 700 rpm
²A/C controls set in 100 percent outside air
²Blower switch in the high A/C position
²A/C in the ON position
²Open all windows
CAUTION: A leak detector designed for R-12 refrig-
erant (only) will not detect leaks in a R-134a refrig-
erant system.
(4) Shut off the vehicle and wait 2 to 7 minutes.
Then use an Electronic Leak Detector that is
designed to detect R-134a type refrigerant and search
for leaks. Fittings, lines, or components that appear
to be oily usually indicates a refrigerant leak. To
inspect the evaporator core for leaks, insert the leak
detector probe into the drain tube opening or a heat
duct. A R-134a dye is available to aid in leak detec-
tion, use only DaimlerChrysler approved refrigerant
dye.
24 - 44 PLUMBINGDR
PLUMBING (Continued)

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

PUMPING ACTION
Action : During portions of this test, the PCM uses
the reed switch to monitor diaphragm movement.
The solenoid is only turned on by the PCM after the
reed switch changes from open to closed, indicating
that the diaphragm has moved down. At other times
during the test, the PCM will rapidly cycle the LDP
solenoid on and off to quickly pressurize the system.
During rapid cycling, the diaphragm will not move
enough to change the reed switch state. In the state
of rapid cycling, the PCM will use a fixed time inter-
val to cycle the solenoid. If the system does not pass
the EVAP Leak Detection Test, the following DTCs
may be set:
²P0442 - EVAP LEAK MONITOR 0.0409LEAK
DETECTED
²P0455 - EVAP LEAK MONITOR LARGE LEAK
DETECTED
²P0456 - EVAP LEAK MONITOR 0.0209LEAK
DETECTED
²P1486 - EVAP LEAK MON PINCHED HOSE
FOUND
²P1494 - LEAK DETECTION PUMP SW OR
MECH FAULT
²P1495 - LEAK DETECTION PUMP SOLENOID
CIRCUIT
REMOVAL
The Leak Detection Pump (LDP) and LDP filter
are attached to the front of the EVAP canister
mounting bracket (Fig. 9). This is located near the
front of the fuel tank. The LDP and LDP filter are
replaced (serviced) as one unit.
(1) Raise and support vehicle.
(2) Carefully remove hose at LDP filter.
(3) Remove LDP filter mounting bolt and remove
from vehicle.
(4) Carefully remove vapor/vacuum lines at LDP.
(5) Disconnect electrical connector at LDP.
(6) Remove LDP mounting bolt and remove LDP
from vehicle.
INSTALLATION
The LDP and LDP filter are attached to the front
of the EVAP canister mounting bracket. The LDP
and LDP filter are replaced (serviced) as one unit.
(1) Install LDP to mounting bracket. Refer to
Torque Specifications.
(2) Install LDP filter to mounting bracket. Refer to
Torque Specifications.
(3) Carefully install vapor/vacuum lines to LDP,
and install hose to LDP filter.The vapor/vacuum
lines and hoses must be firmly connected.
Fig. 8 DIAPHRAGM DOWNWARD MOVEMENT
1 - Diaphragm
2 - Inlet Check Valve (Closed)
3 - Vent Valve (Closed)
4 - From Air Filter
5 - To Canister
6 - Outlet Check Valve (Open)
7 - Engine Vacuum (Closed)
Fig. 9 LDP AND LDP FILTER LOCATION
1 - LDP
2 - LDP MOUNTING BOLT
3 - ELEC. CONNEC.
4 - FILTER MOUNTING BOLT
5 - LDP FILTER
6 - CONNECTING HOSE
7 - EVAP CANISTER MOUNTING BRACKET
8 - EVAP CANISTERS (2)
25 - 16 EVAPORATIVE EMISSIONSDR
LEAK DETECTION PUMP (Continued)

Check the vapor/vacuum lines at the LDP, LDP
filter and EVAP canister purge solenoid for
damage or leaks. If a leak is present, a Diagnos-
tic Trouble Code (DTC) may be set.
(4) Connect electrical connector to LDP.
ORVR
DESCRIPTION
The ORVR (On-Board Refueling Vapor Recovery)
system consists of a unique fuel tank, flow manage-
ment valve, fluid control valve, one-way check valve
and vapor canister.
OPERATION
The ORVR (On-Board Refueling Vapor Recovery)
system is used to remove excess fuel tank vapors.
This is done while the vehicle is being refueled.
Fuel flowing into the fuel filler tube (approx. 1º
I.D.) creates an aspiration effect drawing air into the
fuel fill tube. During refueling, the fuel tank is
vented to the EVAP canister to capture escaping
vapors. With air flowing into the filler tube, there are
no fuel vapors escaping to the atmosphere. Once the
refueling vapors are captured by the EVAP canister,
the vehicle's computer controlled purge system draws
vapor out of the canister for the engine to burn. The
vapor flow is metered by the purge solenoid so that
there is no, or minimal impact on driveability or
tailpipe emissions.
As fuel starts to flow through the fuel fill tube, it
opens the normally closed check valve and enters the
fuel tank. Vapor or air is expelled from the tank
through the control valve and on to the vapor canis-
ter. Vapor is absorbed in the EVAP canister until
vapor flow in the lines stops. This stoppage occurs
following fuel shut-off, or by having the fuel level in
the tank rise high enough to close the control valve.
This control valve contains a float that rises to seal
the large diameter vent path to the EVAP canister.
At this point in the refueling process, fuel tank pres-
sure increases, the check valve closes (preventing liq-
uid fuel from spiting back at the operator), and fuel
then rises up the fuel filler tube to shut off the dis-
pensing nozzle.
PCV VALVE
DESCRIPTION
3.7L V-6 / 4.7L V-8
The 3.7L V-6 and 4.7L V-8 engines are equipped
with a closed crankcase ventilation system and a
Positive Crankcase Ventilation (PCV) valve.
This system consists of:
²a PCV valve mounted to the oil filler housing
(Fig. 10). The PCV valve is sealed to the oil filler
housing with an o-ring.
²the air cleaner housing
²two interconnected breathers threaded into the
rear of each cylinder head (Fig. 11).
²tubes and hoses to connect the system compo-
nents.
Fig. 10 PCV VALVE - 3.7L V-6 / 4.7L V-8
1 - O-RING
2 - LOCATING TABS
3 - CAM LOCK
4 - OIL FILLER TUBE
5 - PCV LINE/HOSE
6 - P C V VA LV E
DREVAPORATIVE EMISSIONS 25 - 17
LEAK DETECTION PUMP (Continued)

5.7L V-8
(1) Clean out intake manifold opening.
(2) Check condition of 2 o-rings on PCV valve.
(3) Apply engine oil to 2 o-rings.
(4) Place PCV valve into intake manifold and
rotate 90 degrees clockwise for installation.
VACUUM LINES
DESCRIPTION
A vacuum schematic for emission related items can
be found on the vehicles VECI label. Refer to Vehicle
Emission Control Information (VECI) Label for label
location.
VAPOR CANISTER
DESCRIPTION
Two, maintenance free, EVAP canisters are used.
Both canisters are mounted into a two-piece support
bracket located near the front of the fuel tank (Fig.
23).
OPERATION
Two, maintenance free, EVAP canisters are
used.The EVAP canisters are filled with granules of
an activated carbon mixture. Fuel vapors entering
the EVAP canisters are absorbed by the charcoal
granules.
Fuel tank pressure vents into the EVAP canisters.
Fuel vapors are temporarily held in the canisters
until they can be drawn into the intake manifold.
The duty cycle EVAP canister purge solenoid allows
the EVAP canisters to be purged at predetermined
times and at certain engine operating conditions.
REMOVAL
Two, maintenance free, EVAP canisters are used.
Both canisters are mounted into a two-piece support
bracket located near the front of the fuel tank (Fig.
23).
(1) Raise and support vehicle.
(2) Remove fuel tubes/lines at each EVAP canister.
Note location of tubes/lines before removal for easier
installation.
(3) Remove lower support bracket (Fig. 24).
(4) Remove mounting nuts at top of each canister
(Fig. 24).
(5) Remove each canister from upper support
bracket.
INSTALLATION
(1) Place each canister into upper support bracket
and install nuts. Refer to Torque Specifications.
(2) Install lower support bracket. Refer to Torque
Specifications.
(3) Carefully install vapor/vacuum lines.The
vapor/vacuum lines and hoses must be firmly
connected. Also check the vapor/vacuum lines
at the LDP, LDP filter and EVAP canister purge
solenoid for damage or leaks. If a leak is
present, a Diagnostic Trouble Code (DTC) may
be set.
Fig. 23 LOCATION, EVAP CANISTERS
1 - LDP
2 - LDP MOUNTING BOLT
3 - ELEC. CONNEC.
4 - FILTER MOUNTING BOLT
5 - LDP FILTER
6 - CONNECTING HOSE
7 - EVAP CANISTER MOUNTING BRACKET
8 - EVAP CANISTERS (2)
25 - 22 EVAPORATIVE EMISSIONSDR
PCV VALVE (Continued)

The NVLD device is designed with a normally open
vacuum switch, a normally closed solenoid, and a
seal, which is actuated by both the solenoid and a
diaphragm. The NVLD is located on the atmospheric
vent side of the canister. The NVLD assembly may
be mounted on top of the canister outlet, or in-line
between the canister and atmospheric vent filter. The
normally open vacuum switch will close with about 19
H2O (0.25 KPA) vacuum in the evaporative system.
The diaphragm actuates the switch. This is above the
opening point of the fuel inlet check valve in the fill
tube so cap off leaks can be detected. Submerged fill
systems must have recirculation lines that do not
have the in-line normally closed check valve that pro-
tects the system from failed nozzle liquid ingestion,
in order to detect cap off conditions.
The normally closed valve in the NVLD is intended
to maintain the seal on the evaporative system dur-
ing the engine off condition. If vacuum in the evapo-
rative system exceeds 39to 69H2O (0.75 to 1.5 KPA),
the valve will be pulled off the seat, opening the seal.
This will protect the system from excessive vacuum
as well as allowing sufficient purge flow in the event
that the solenoid was to become inoperative.
The solenoid actuates the valve to unseal the can-
ister vent while the engine is running. It also will be
used to close the vent during the medium and large
leak tests and during the purge flow check. This sole-
noid requires initial 1.5 amps of current to pull the
valve open but after 100 ms. will be duty cycled down
to an average of about 150 mA for the remainder of
the drive cycle.
Another feature in the device is a diaphragm that
will open the seal in the NVLD with pressure in the
evaporative system. The device will9blow off9at
about 0.59H2O (0.12 KPA) pressure to permit the
venting of vapors during refueling. An added benefit
to this is that it will also allow the tank to9breathe9
during increasing temperatures, thus limiting the
pressure in the tank to this low level. This is benefi-
cial because the induced vacuum during a subse-
quent declining temperature will achieve the switch
closed (pass threshold) sooner than if the tank had to
decay from a built up pressure.
The device itself has 3 wires: Switch sense, sole-
noid driver and ground. It also includes a resistor to
protect the switch from a short to battery or a short
to ground. The NGC utilizes a high-side driver to
energize and duty-cycle the solenoid.REMOVAL
The NVLD pump and filter are attached to the
front of the EVAP canister mounting bracket (Fig.
25). This is located near the front of the fuel tank.
The pump and filter are replaced (serviced) as one
unit.
(1) Raise and support vehicle.
(2) Carefully remove pump hose clamp and hose at
filter.
(3) Carefully remove other vapor/vacuum hose at
pump.
(4) Disconnect 3±way electrical connector at pump.
(5) The NVLD pump snaps onto the EVAP canister
mounting bracket. Press on release tab (Fig. 26)
while sliding pump from bracket.
Fig. 25 NVLD PUMP LOCATION
1 - EVAP CANISTER MOUNTING BRACKET
2 - NVLD PUMP
3 - FILTER
25 - 24 EVAPORATIVE EMISSIONSDR
NATURAL VAC LEAK DETECTION ASSY (Continued)