1998 DODGE RAM 1500 fuel tank removal

Tank Removal
(1) Loosen clamp and disconnect rubber fuel vent
hose (Fig. 23) at tank fitting.
(2) Support tank with a hydraulic jack.
(3) Remove 2 fuel tank strap nuts (Fig. 24) and
remove both tank support straps.
(4) Carefully lower tank a few inches and discon-
nect fuel pump module electrical connector (Fig. 25)
at top of tank. To disconnect electrical connector:
Push upward on red colored tab to unlock. Push on
black colored tab while removing connector.(5) Disconnect fuel line at fuel filter / fuel pressure
regulator (Fig. 25) by pressing on tabs at side of
quick-connect fitting.
(6) Disconnect EVAP line at top of tank (Fig. 1).
(7) Continue to lower tank for removal.
(8) If fuel tank is to be replaced, remove fuel pump
module from tank. Refer to Fuel Pump Module
Removal/Installation procedures.
Fig. 23 FUEL TANK FILL / VENT HOSES
1 - BEZEL SCREWS
2 - FUEL FILL BEZEL
3 - HOSE CLAMPS4 - VENT HOSE
5 - FUEL TANK
6 - FILL HOSE
14 - 18 FUEL DELIVERY - GASDR
FUEL TANK (Continued)

INSTALLATION - EXCEPT DIESEL
(1) If fuel tank is to be replaced, install fuel pump
module into tank. Refer to Fuel Pump Module
Removal/Installation procedures.
(2) Disconnect clamps and remove rubber fuel fill
hose and fuel vent hose at fuel fill tube. Install these
2 hoses to 2 fuel tank fittings. Rotate hoses until
paint marks on hoses line up with alignment marks
(Fig. 26). Tighten both clamps.
(3) Position fuel tank to hydraulic jack.
(4) Raise tank until positioned near body.
(5) Connect EVAP line at tank (Fig. 1).
(6) Connect fuel pump module electrical connector
(Fig. 25) at top of tank.
(7) Connect fuel line quick-connect fitting to fuel
filter / fuel pressure regulator (Fig. 1) or (Fig. 25).
(8) Continue raising tank until positioned snug to
body.(9) Install and position both tank support straps.
Install 2 fuel tank strap nuts (Fig. 24) and tighten.
Tighten rear strap nut first.Refer to Torque Spec-
ifications.
(10) Connect rubber fill and vent hoses to fuel fill
tube and tighten clamps.
(11) Lower vehicle.
(12) Fill fuel tank with fuel.
(13) Start engine and check for fuel leaks near top
of module.
Fig. 24 FUEL TANK MOUNTING
1 - FUEL TANK
2 - STRAP MOUNTING STUDS
3 - VEHICLE FRAME4 - MOUNTING STRAPS
5 - STRAP NUTS
DRFUEL DELIVERY - GAS 14 - 19
FUEL TANK (Continued)

INLET FILTER
REMOVAL
The fuel pump inlet filter (strainer) is located on
the bottom of the fuel pump module (Fig. 27). The
fuel pump module is located inside of fuel tank.
(1) Remove fuel tank. Refer to Fuel Tank Removal/
Installation.
(2) Remove fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Remove filter by carefully prying 2 lock tabs at
bottom of module with 2 screwdrivers. Filter is
snapped to module.
(4) Clean bottom of pump module.
INSTALLATION
The fuel pump inlet filter (strainer) is located on
the bottom of the fuel pump module (Fig. 27). The
fuel pump module is located inside of fuel tank.
(1) Snap new filter to bottom of module. Be sure
o-ring is in correct position.
(2) Install fuel pump module. Refer to Fuel Pump
Module Removal/Installation.
(3) Install fuel tank. Refer to Fuel Tank Removal/
Installation.
Fig. 25 FUEL PUMP MODULE CONNECTIONS
1 - TOP OF FUEL TANK
2 - FUEL PUMP MODULE
3 - FUEL FILTER / FUEL PRESSURE REGULATOR
4 - ELEC. CONNECT.
Fig. 26 HOSE ALIGNMENT MARKS
1 - ALIGNMENT MARKS (MARK FOR FILL HOSE IS LOCATED
ON FUEL TANK - MARK FOR VENT HOSE IS LOCATED ON
FITTING)
2 - PAINT MARKS ON RUBBER HOSES
Fig. 27 FUEL PUMP INLET FILTER
1 - FUEL PUMP INLET FILTER
2 - LOCK TABS (2)
3 - FUEL PUMP MODULE (BOTTOM)
14 - 20 FUEL DELIVERY - GASDR
FUEL TANK (Continued)

FUEL DELIVERY - DIESEL
TABLE OF CONTENTS
page page
FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM.....45
STANDARD PROCEDURE
STANDARD PROCEDURES - WATER
DRAINING AT FUEL FILTER..............47
STANDARD PROCEDURES - CLEANING
FUEL SYSTEM PARTS.................47
STANDARD PROCEDURE - FUEL SYSTEM
PRIMING............................47
SPECIFICATIONS
FUEL INJECTOR FIRING ORDER - DIESEL . 48
TORQUE - FUEL SYSTEM - DIESEL
ENGINE.............................48
SPECIAL TOOLS
DIESEL FUEL SYSTEM.................49
FUEL FILTER / WATER SEPARATOR
DESCRIPTION.........................50
OPERATION...........................50
REMOVAL.............................50
INSTALLATION.........................50
FUEL HEATER
DESCRIPTION.........................51
OPERATION...........................51
DIAGNOSIS AND TESTING - FUEL HEATER . . . 52
REMOVAL
REMOVAL/INSTALLATION...............52
FUEL HEATER RELAY
DESCRIPTION.........................52
OPERATION...........................52
REMOVAL.............................52
INSTALLATION.........................53
FUEL INJECTION PUMP
DESCRIPTION.........................53
OPERATION...........................53
DIAGNOSIS AND TESTING - FUEL INJECTION
PUMP TIMING........................53
REMOVAL.............................54
INSTALLATION.........................55
FUEL LEVEL SENDING UNIT / SENSOR
DESCRIPTION.........................57
OPERATION...........................57
REMOVAL
REMOVAL/INSTALLATION...............57FUEL LINES
DESCRIPTION.........................57
OPERATION...........................57
DIAGNOSIS AND TESTING - HIGH-
PRESSURE FUEL LINE LEAKS...........58
REMOVAL.............................58
INSTALLATION.........................60
FUEL PRESSURE SENSOR
DESCRIPTION.........................60
OPERATION...........................60
REMOVAL.............................60
INSTALLATION.........................61
FUEL PRESSURE LIMITING VALVE
DESCRIPTION.........................61
OPERATION...........................61
REMOVAL.............................61
INSTALLATION.........................61
FUEL TANK
DESCRIPTION - DIESEL..................62
REMOVAL - DIESEL.....................62
INSTALLATION - DIESEL.................62
FUEL TANK MODULE
DESCRIPTION.........................63
OPERATION...........................63
REMOVAL.............................63
INSTALLATION.........................64
FUEL TRANSFER PUMP
DESCRIPTION.........................64
OPERATION...........................64
REMOVAL.............................64
INSTALLATION.........................65
CASCADE OVERFLOW VALVE
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL
REMOVAL/INSTALLATION...............66
WATER IN FUEL SENSOR
DESCRIPTION.........................66
OPERATION...........................66
REMOVAL.............................66
FUEL DRAIN CIRCUIT
OPERATION...........................67
14 - 44 FUEL DELIVERY - DIESELDR

STANDARD PROCEDURE
STANDARD PROCEDURES - WATER DRAINING
AT FUEL FILTER
Refer to Fuel Filter/Water Separator removal/in-
stallation for procedures.
STANDARD PROCEDURES - CLEANING FUEL
SYSTEM PARTS
CAUTION: Cleanliness cannot be overemphasized
when handling or replacing diesel fuel system com-
ponents. This especially includes the fuel injectors,
high-pressure fuel lines and fuel injection pump.
Very tight tolerances are used with these parts. Dirt
contamination could cause rapid part wear and pos-
sible plugging of fuel injector nozzle tip holes. This
in turn could lead to possible engine misfire.
Always wash/clean any fuel system component
thoroughly before disassembly and then air dry.
Cap or cover any open part after disassembly.
Before assembly, examine each part for dirt, grease
or other contaminants and clean if necessary. When
installing new parts, lubricate them with clean
engine oil or clean diesel fuel only.
STANDARD PROCEDURE - FUEL SYSTEM
PRIMING
A certain amount of air becomes trapped in the
fuel system when fuel system components on the
supply and/or high-pressure side are serviced or
replaced. Fuel system priming is accomplished using
the electric fuel transfer (lift) pump.
Servicing or replacing fuel system components will
not require fuel system priming.
The fuel transfer (lift) pump is self-priming: When
the key is first turned on (without cranking engine),
the pump operates for approximately 1 to 2 second
and then shuts off. The pump will also operate for up
to 25 seconds after the starter is quickly engaged,
and then disengaged without allowing the engine to
start. The pump shuts off immediately if the key is
on and the engine stops running.
(1) Turn key to CRANK position and quickly
release key to ON position before engine starts. This
will operate fuel transfer pump for approximately 25
seconds.
(2) Crank engine. If the engine does not start after
25 seconds, turn key OFF. Repeat previous step until
engine starts.
(3) Fuel system priming is now completed.
(4) Attempt to start engine. If engine will not
start, proceed to following steps.When engine does
start, it may run erratically and be noisy for a
few minutes. This is a normal condition.
CAUTION: Do not engage the starter motor for more
than 30 seconds at a time. Allow two minutes
between cranking intervals.
(5) Perform previous fuel priming procedure steps
using fuel transfer pump. Be sure fuel is present at
fuel tank.
(6) Crank the engine for 30 seconds at a time to
allow fuel system to prime.
WARNING: THE FUEL INJECTION PUMP SUPPLIES
EXTREMELY HIGH FUEL PRESSURE TO EACH INDI-
VIDUAL INJECTOR THROUGH THE HIGH-PRES-
SURE LINES. FUEL UNDER THIS AMOUNT OF
PRESSURE CAN PENETRATE THE SKIN AND
CAUSE PERSONAL INJURY. WEAR SAFETY GOG-
GLES AND ADEQUATE PROTECTIVE CLOTHING.
DO NOT LOOSEN FUEL FITTINGS WHILE ENGINE
IS RUNNING.
WARNING: ENGINE MAY START WHILE CRANKING
STARTER MOTOR.
Fig. 2 FUEL INJECTORS
1 - SOLENOID CONNECTIONS
2 - ROCKER HOUSING
3 - FUEL INJECTOR
4 - PASSTHROUGH CONNECTOR
DRFUEL DELIVERY - DIESEL 14 - 47
FUEL DELIVERY - DIESEL (Continued)

SPECIAL TOOLS
DIESEL FUEL SYSTEM
FUEL PRESSURE TEST ADAPTER - # 9012
FUEL PRESSURE TEST ADAPTER - #9014
FUEL INJECTOR REMOVER - #9010
PRESSURE CAP - #9011
FUEL PRESSURE TEST ADAPTER - #9013
FUEL INJECTOR TUBE (CONNECTOR) REMOVER -
#9015
SPANNER WRENCH (FUEL TANK MODULE
REMOVAL/INSTALLATION) - #6856
DRFUEL DELIVERY - DIESEL 14 - 49
FUEL DELIVERY - DIESEL (Continued)

FUEL LEVEL SENDING UNIT /
SENSOR
DESCRIPTION
The fuel gauge sending unit (fuel level sensor) is
attached to the side of the fuel tank module. The
sending unit consists of a float, an arm, and a vari-
able resistor track (card).
OPERATION
The fuel tank module on diesel powered models
has 2 different circuits (wires). Two of these circuits
are used at the fuel gauge sending unit for fuel
gauge operation. The diesel engine does not have a
fuel tank module mounted electric fuel pump. The
electric fuel pump (fuel transfer pump) is mounted to
the engine.
For Fuel Gauge Operation:A constant input
voltage source of about 12 volts (battery voltage) is
supplied to the resistor track on the fuel gauge send-
ing unit. This is fed directly from the Engine Control
Module (ECM).NOTE: For diagnostic purposes,
this 12V power source can only be verified with
the circuit opened (fuel tank module electrical
connector unplugged). With the connectors
plugged, output voltages will vary from about .6
volts at FULL, to about 7.0 volts at EMPTY.The
resistor track is used to vary the voltage (resistance)
depending on fuel tank float level. As fuel level
increases, the float and arm move up, which
decreases voltage. As fuel level decreases, the float
and arm move down, which increases voltage. The
varied voltage signal is returned back to the ECM
through the sensor return circuit.
Both of the electrical circuits between the fuel
gauge sending unit and the ECM are hard-wired (not
multi-plexed). After the voltage signal is sent from
the resistor track, and back to the ECM, the ECM
will interpret the resistance (voltage) data and send
a message across the multi-plex bus circuits to the
instrument panel cluster. Here it is translated into
the appropriate fuel gauge level reading. Refer to
Instrument Panel for additional information.
REMOVAL
REMOVAL/INSTALLATION
For diesel removal and installation procedures,
refer to the gas section of Fuel System/Fuel Delivery.
See Fuel Level Sending Unit/Sensor Removal/Instal-
lation.
FUEL LINES
DESCRIPTION
Low-Pressure Lines Are:
²the fuel supply line from fuel tank to fuel trans-
fer (lift) pump.
²the fuel return line back to fuel tank.
²the fuel drain (manifold) line at rear of cylinder
head.
²the fuel supply line from fuel filter to fuel injec-
tion pump.
²the fuel injection pump return line.
High-Pressure Lines Are:
²the fuel line from fuel injection pump to fuel
rail.
²the 6 fuel lines from fuel rail up to injector con-
nector tubes
WARNING: HIGH-PRESSURE FUEL LINES DELIVER
DIESEL FUEL UNDER EXTREME PRESSURE FROM
THE INJECTION PUMP TO THE FUEL INJECTORS.
THIS MAY BE AS HIGH AS 160,000 KPA (23,206
PSI). USE EXTREME CAUTION WHEN INSPECTING
FOR HIGH-PRESSURE FUEL LEAKS. INSPECT FOR
HIGH-PRESSURE FUEL LEAKS WITH A SHEET OF
CARDBOARD. HIGH FUEL INJECTION PRESSURE
CAN CAUSE PERSONAL INJURY IF CONTACT IS
MADE WITH THE SKIN.
OPERATION
High-Pressure Lines
CAUTION: The high-pressure fuel lines must be
held securely in place in their holders. The lines
cannot contact each other or other components. Do
not attempt to weld high-pressure fuel lines or to
repair lines that are damaged. If lines are ever
kinked or bent, they must be replaced. Use only the
recommended lines when replacement of high-pres-
sure fuel line is necessary.
High-pressure fuel lines deliver fuel (under pres-
sure) of up to approximately 160,000 kPa (23,206
PSI) from the injection pump to the fuel injectors.
The lines expand and contract from the high-pres-
sure fuel pulses generated during the injection pro-
cess. All high-pressure fuel lines are of the same
length and inside diameter. Correct high-pressure
fuel line usage and installation is critical to smooth
engine operation.
DRFUEL DELIVERY - DIESEL 14 - 57

FUEL TANK
DESCRIPTION - DIESEL
The fuel tank is similar to the tank used with gas-
oline powered models. The tank is equipped with a
separate fuel return line and a different fuel tank
module for diesel powered models. A fuel tank
mounted, electric fuel pump is not used with diesel
powered models. Refer to Fuel Tank Module for addi-
tional information.
REMOVAL - DIESEL
Fuel Tank Draining
Due to a one-way check valve installed into the
fuel fill opening fitting at the tank, the tank cannot
be drained conventionally at the fill cap.
(1) Raise vehicle.
(2) If vehicle is equipped with 4 doors and a 6 foot
(short) box, remove left-rear tire/wheel.
(3) Thoroughly clean area at top of fuel tank
around fuel tank module.
(4) Remove rubber cap from auxiliary fitting on
top of tank module (Fig. 19).
(5) Drain fuel tank by attaching drain hose from
an approved draining station to auxiliary fitting on
top of tank module (Fig. 19).
Tank Removal
(1) Loosen clamp and disconnect rubber fuel fill
hose at tank.
(2) Support tank with a hydraulic jack.
(3) Remove 2 fuel tank strap nuts (Fig. 20) and
remove both tank support straps.
(4) Carefully lower tank a few inches and discon-
nect fuel pump module electrical connector (Fig. 19)
at top of tank. To disconnect electrical connector:
Push upward on red colored tab to unlock. Push on
black colored tab while removing connector.
(5) Disconnect fuel supply and return lines at fuel
tank module (Fig. 19). Refer to Quick-Connect Fit-
tings for procedures.
(6) Continue to lower tank for removal.
(7) If fuel tank is to be replaced, remove fuel tank
module from tank. Refer to Fuel Tank Module
Removal/Installation procedures.INSTALLATION - DIESEL
(1) If fuel tank is to be replaced, install fuel tank
module into tank. Refer to Fuel Tank Module Remov-
al/Installation procedures.
(2) Position fuel tank to hydraulic jack.
(3) Raise tank until positioned near body.
(4) Connect fuel tank module electrical connector
at top of tank.
(5) Connect fuel supply and return lines to tank
module.
(6) Continue raising tank until positioned snug to
body.
(7) Install and position both tank support straps.
Install 2 fuel tank strap nuts and tighten.Tighten
rear strap nut first.Refer to Torque Specifications.
(8) Remove hydraulic jack.
(9) Connect rubber fill hose to fuel fill tube and
tighten clamp.
(10) Install tire / wheel (if necessary).
(11) Lower vehicle.
(12) Fill fuel tank with fuel.
(13) Start engine and check for fuel leaks near top
of module.
Fig. 19 FUEL TANK MODULE - DIESEL
1 - TOP OF FUEL TANK
2 - AUX. FITTING
3 - ELEC. CONNECTOR
4 - FUEL TANK MODULE (TOP)
5 - LOCKNUT
6 - FUEL SUPPLY LINE
7 - FUEL RETURN LINE
14 - 62 FUEL DELIVERY - DIESELDR