1998 DODGE RAM 1500 gear

OIL PRESSURE RELIEF VALVE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the threaded plug, spring and plunger
(Fig. 108). Insert a finger or a seal pick to lift the
plunger from the bore.
NOTE: If the plunger is stuck in the bore, it will be
necessary to remove the filter head.
CLEANING
(1) Clean the regulator spring and plunger with a
suitable solvent and blow dry with compressed air. If
the plunger bore requires cleaning, it is necessary to
remove the oil filter head to avoid getting debris into
the engine.
INSPECTION
Inspect the plunger and plunger bore for cracks
and excessive wear. Polished surfaces are acceptable.
Verify that the plunger moves freely in the bore.
Check the spring for height and load limitations
(Fig. 109). Replace the spring if out of limits shown
in the figure.
INSTALLATION
(1) Install the plunger, spring, and plug as shown
in (Fig. 108). Tighten the plug to 80 N´m (59 ft. lbs.)
torque.
(2) Connect the battery negative cables.
(3) Start the engine and verify that it has oil pres-
sure.
OIL PRESSURE SWITCH
REMOVAL
(1) Disconnect the battery negative cables.
(2) Disconnect the oil pressure switch connector.
(3) Using a suitable socket, remove the oil pres-
sure switch from the block (counter-clockwise).
INSTALLATION
(1) If the switch is not being replaced, replace and
lubricate the o-ring.
(2) Install the oil pressure switch and tighten to
18 N´m (159 in. lbs.) torque.
(3) Connect oil pressure switch connector.
(4) Connect the battery negative cables.
(5) Start engine and check for oil leaks at the
switch.
OIL PUMP
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove fan/drive assembly (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - REMOVAL).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the fan support/hub assembly.
(5) Remove crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and speed indicator ring.
(6) Remove power steering pump.
(7) Remove accessory drive belt tensioner.
(8) Remove the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- REMOVAL).
Fig. 108 Oil Pressure Regulator
1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE
Fig. 109 Oil Pressure Regulator Spring Check
9 - 294 ENGINE 5.9L DIESELDR

(9) Remove the four mounting bolts and pull the
oil pump from the bore in the cylinder block (Fig.
110).
CLEANING
Clean all parts in solvent and dry with compressed
air. Clean the old sealer residue from the back of the
gear housing cover and front of the gear housing.
INSPECTION
Disassemble and inspect the oil pump as fol-
lows:
(1) Visually inspect the lube pump gears for chips,
cracks or excessive wear.
(2) Remove the back plate (Fig. 111).
(3) Mark TOP on the gerotor planetary using a felt
tip pen (Fig. 111).
(4) Remove the gerotor planetary (Fig. 111).
Inspect for excessive wear or damage. Inspect the
pump housing and gerotor drive for damaged and
excessive wear.
(5) Install the gerotor planetary in the original
position.
(6) Measure the tip clearance (Fig. 112). Maximum
clearance is 0.1778 mm (0.007 inch). If the oil pump
is out of limits, replace the pump.
(7) Measure the clearance of the gerotor drive/
gerotor planetary to port plate (Fig. 113). Maximum
clearance is 0.127 mm (0.005 inch). If the oil pump is
out of limits, replace the pump.
Fig. 110 Oil Pump Removal/Installation
1 - OIL PUMP
2 - BOLT (4)
Fig. 111 Gerotor Planetary and Gerotor
1 - OIL PUMP BACK PLATE
2 - GEROTOR
3 - GEROTOR PLANETARY
Fig. 112 Measuring Tip Clearance
1 - FEELER GAUGE
Fig. 113 Measuring Gerotor to Port Plate Clearance
1 - PORT PLATE
2 - GEROTOR
DRENGINE 5.9L DIESEL 9 - 295
OIL PUMP (Continued)

(8) Measure the clearance of the gerotor planetary
to the body bore (Fig. 114). Maximum clearance is
0.381 mm (0.015 inch). If the oil pump is out of lim-
its, replace the pump.
(9) Measure the gears backlash (Fig. 115). The lim-
its of a used pump is 0.15- 0.25 mm (0.006-0.010
inch). If the backlash is out of limits, replace the oil
pump.
(10) Install the back plate.
INSTALLATION
(1) Lubricate the pump with clean engine oil. Fill-
ing the pump with clean engine oil during installa-
tion will help to prime the pump at engine start up.
(2) Install the pump (Fig. 110). Verify the idler
gear pin is installed in the locating bore in the cylin-
der block. Tighten the oil pump mounting bolts in
two steps, in the sequence shown in (Fig. 116).
²Step 1ÐTighten to 8 N´m (71 in. lbs.) torque.
²Step 2ÐTighten to 24 N´m (18 ft. lbs.) torque.
(3) The back plate on the pump seats against the
bottom of the bore in the cylinder block. When the
pump is correctly installed, the flange on the pump
will not touch the cylinder block.(4) Measure the idler gear to pump drive gear
backlash and the idler gear to crankshaft gear back-
lash (Fig. 117). The backlash should be 0.15- 0.25
mm (0.006-0.010 inch). If the backlash is out of lim-
its, replace the oil pump.
(5) If the adjoining gear moves when you measure
the backlash, the reading will be incorrect.
(6) Apply a bead of MopartSilicone Rubber Adhe-
sive Sealant or equivalent to the gear housing cover
sealing surface.
(7) Install the gear housing cover (Refer to 9 -
ENGINE/VALVE TIMING/GEAR HOUSING COVER
- INSTALLATION).
(8) Install the vibration damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION) and speed indicator ring.
(9) Install the fan support/hub assembly Refer to
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION)
(10) Install power steering pump.
(11) Install accessory drive belt tensioner. Torque
bolt to 43 N´m (32 ft. lbs.).
(12) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
Fig. 114 Measuring Gerotor Planetary to Body Bore
Clearance
1 - BODY BORE
2 - GEROTOR PLANETARY
Fig. 115 Measure Gear Backlash
1 - OIL PUMP DRIVE GEAR
2 - IDLER GEAR
3 - BACKLASH
4 - BACKLASH
Fig. 116 Oil Pump Mounting Bolt Torque Sequence
Fig. 117 Idler Gear to Pump Drive Gear and
Crankshaft Gear Backlash
9 - 296 ENGINE 5.9L DIESELDR
OIL PUMP (Continued)

(3) Install heat shield and torque nuts to 15 Nm
(11 ft. lbs.).
(4) Install cab heater tube.
(5) Install exhaust manifold bolt retention straps.
(6) Install the cab heater return hose to the man-
ifold bolt stud. Tighten the nut to 24 N´m (18 ft. lbs.)
torque.
(7) Install the turbocharger and a new gasket.
Apply anti-seize to the studs and then tighten the
turbocharger mounting nuts to 43 N´m (32 ft. lbs.)
torque.
(8)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting on the turbo. Rotate the turbocharger impeller
by hand to distrubute the oil thoroughly.
(9) Install and tighten the oil supply line fitting
nut to 24 N´m (18 ft. lbs.) torque.
(10) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (100 in. lbs.) torque.
(11) Position the air inlet hose to the turbocharger.
Tighten the clamp to 11 N´m (100 in. lbs.) torque.
(12) Raise vehicle on hoist.
(13) Install the oil drain tube and a new gasket to
the turbocharger. Tighten the drain tube bolts to 24
N´m (18 ft. lbs.) torque.
(14) Connect the exhaust pipe to the turbocharger
and tighten the bolts to 11 N´m (100 ft. lbs.) torque.
(15) Lower the vehicle.
(16) Connect the battery negative cables.
(17) Start the engine to check for leaks.
VALVE TIMING
STANDARD PROCEDURE - TIMING
VERIFICATION
(1) Remove the cylinder head cover(Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - REMOVAL).
(2) Remove fuel injector from cylinder number
1(Refer to 14 - FUEL SYSTEM/FUEL INJECTION/
FUEL INJECTOR - REMOVAL).
(3) Using Special Tool 7471B rotate the engine
until the TDC mark on the damper is at 12 o'clock.
(4) Using a 8 in.x 1/4 in. dowel rod inserted into
cylinder number 1, rock the crankshaft back and
forth to verify piston number 1 is at TDC.
(5) With cylinder number still at TDC, inspect the
keyway on the crankshaft gear for proper alignment
(12 o'clock position).
(6) If the keyway is not at 12 o'clock position
replace the crankshaft gear assembly.
(7) If the keyway is at 12 o'clock position, remove
front gear cover and verify timing mark alignmentbetween the camshaft gear and crankshaft gear, if
not aligned inspect keyway on camshaft gear.
(8) Inspect keyway on camshaft gear for proper
alignment with the key in the camshaft, if alignment
is off replace the camshaft/gear assembly.
(9) If timing marks alignment is off and no dam-
age is found at either the crankshaft or camshaft
gear keyways, realign timing marks as necessary.
GEAR HOUSING
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
(8) Remove lower fan shroud fasteners. Disconnect
fan drive wire harness.
(9) Remove the upper fan shroud-to-radiator
mounting bolts.
(10) Remove viscous fan/drive assembly (Refer to 7
- COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(11) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(12) Remove the cooling fan support/hub from the
front of the engine.
(13) Raise the vehicle on hoist.
(14) Remove the crankshaft damper (Refer to 9 -
ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
REMOVAL) and speed indicator ring.
(15) Lower the vehicle.
(16) Remove the power steering pump.
(17) Remove the accessory drive belt tensioner.
(18) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing, taking
care not to mar the gasket surfaces.
(19) Remove the fuel injection pump (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL INJEC-
TION PUMP - REMOVAL).
(20) Disconnect the camshaft position sensor con-
nector.
(21) Disconnect and remove engine speed sensor.
(22) Remove the camshaft (Refer to 9 - ENGINE/
ENGINE BLOCK/CAMSHAFT & BEARINGS (IN
BLOCK) - REMOVAL).
(23) Remove the six front oil pan fasteners.
DRENGINE 5.9L DIESEL 9 - 299
EXHAUST MANIFOLD (Continued)

(24) Remove the gear housing fasteners.
NOTE: Use care when removing the gear housing,
to avoid damage to the oil pan gasket, as the gas-
ket will be reused if it is not damaged.
(25) Slide a feeler gauge between the gear housing
and oil pan gasket, to break the gasket seal.
(26) Remove the gear housing and gasket.
(27) Clean the gasket material from the cylinder
block and gear housing.
INSTALLATION
(1) Inspect oil pan gasket. If torn, gasket must be
replaced.
(2) Install a new gear housing gasket onto cylinder
block and trim any excesss gasket material flush to
oil pan rail.
(3) Install the gear housing. Torque bolts to 24
N´m (18 ft. lbs.) (Fig. 121).
(4) If a new housing is installed, the camshaft
position sensor, and engine speed sensor must be
transferred to the new housing.
(5) Connect the camshaft position sensor connec-
tor.
(6) Install and connect engine speed sensor.
(7) Install the injection pump (Refer to 14 - FUEL
SYSTEM/FUEL DELIVERY/FUEL INJECTION
PUMP - INSTALLATION).
(8) Install the camshaft (Refer to 9 - ENGINE/EN-
GINE BLOCK/CAMSHAFT & BEARINGS (INBLOCK) - INSTALLATION). Align the crankshaft
and camshaft gear marks as shown in (Fig. 122).
(9) Install a new front crankshaft seal into the
gear cover.
(10) Apply a bead of MopartSilicone Rubber
Adhesive Sealant or equivalent to the gear housing
cover. Be sure to surround all through holes.
(11) Using the seal pilot to align the cover, install
the cover to the housing and install the bolts.
Tighten the bolts to 24 N´m (18 ft. lbs.) torque.
(12) Remove the seal pilot. Install front seal dust
shield.
(13) Raise the vehicle.
(14) Trim any excess gear housing gasket to make
it flush with the oil pan rail.
(15) Install the crankshaft damper and speed indi-
cator ring (Refer to 9 - ENGINE/ENGINE BLOCK/
VIBRATION DAMPER - INSTALLATION). Torque
bolts to 40 Nm (30 ft. lbs.), plus an additional 60É.
(16) Lower vehicle.
(17) Install the fan support/hub assembly and
tighten bolts to 32 N´m (24 ft. lbs.) torque.
(18) Install the power steering pump.
(19) Install the accessory drive belt tensioner.
Torque bolt to 43 N´m (32 ft. lbs.) torque.
(20) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(21) Install the upper cooling fan and shroud
together (Refer to 7 - COOLING/ENGINE/RADIA-
TOR FAN - INSTALLATION).
(22) Install lower shroud and connect fan drive
harness connector.
Fig. 121 GEAR HOUSING CAPSCREW TORQUE
SEQUENCE
Fig. 122 Timing Mark Alignment
9 - 300 ENGINE 5.9L DIESELDR
GEAR HOUSING (Continued)

(23) Install the windshield washer reservoir to the
fan shroud and connect the washer pump supply
hose and electrical connection.
(24) Install the coolant recovery bottle to the fan
shroud and connect the hose to the radiator filler
neck.
(25) Install the radiator upper hose and clamps.
(26) Add engine oil.
(27) Add coolant (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(28) Connect the battery cables.
(29) Start engine and inspect for leaks.
GEAR HOUSING COVER
REMOVAL
(1) Disconnect both battery negative cables.
(2) Raise vehicle on hoist.
(3) Partially drain engine coolant into container
suitable for re-use (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(4) Lower vehicle.
(5) Remove radiator upper hose.
(6) Disconnect coolant recovery bottle hose from
radiator filler neck and lift bottle off of fan shroud.
(7) Disconnect windshield washer pump supply
hose and electrical connections and lift washer bottle
off of fan shroud.
(8) Remove viscous fan/drive assembly (Refer to 7 -
COOLING/ENGINE/RADIATOR FAN - REMOVAL).
(9) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(10) Remove the cooling fan support/hub from the
front of the engine.
(11) Raise the vehicle on hoist.
(12) Remove power steering pump.
(13) Remove accessory drive belt tensioner.
(14) Remove the crankshaft damper and speed
indicator ring (Refer to 9 - ENGINE/ENGINE
BLOCK/VIBRATION DAMPER - REMOVAL).
(15) Lower the vehicle.
(16) Remove the gear cover-to-housing bolts and
gently pry the cover away from the housing, taking
care not to mar the gasket surfaces.
INSTALLATION
(1) Install a new front crankshaft oil seal.
(2) Obtain a seal pilot/installation tool from a
crankshaft front seal service kit and install the pilot
into the seal.
(3) Apply a bead of MopartSilicone Rubber Adhe-
sive Sealant or equivalent to the gear housing cover.
Be sure to surround all through holes.(4) Using the seal pilot to align the cover (Fig.
123), install the cover to the housing and install the
bolts. Tighten the bolts to 24 N´m (18 ft. lbs.) torque.
(5) Remove the seal pilot. Install front seal dust
shield.
(6) Raise the vehicle.
(7) Install the speed indicator ring and the crank-
shaft damper (Refer to 9 - ENGINE/ENGINE
BLOCK/VIBRATION DAMPER - INSTALLATION).
(8) Lower vehicle.
(9) Install the fan support/hub assy, and tighten
bolts to 32 N´m (24 ft. lbs.) torque.
(10) Install power steering pump.
(11) Install accessory drive belt tensioner. Torque
bolt to 43 N´m (32 ft. lbs.) torque.
(12) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(13) Install the cooling fan and shroud together
(Refer to 7 - COOLING/ENGINE/RADIATOR FAN -
INSTALLATION).
(14) Install the windshield washer reservoir to the
fan shroud and connect the washer pump supply
hose and electrical connection.
(15) Install the coolant recovery bottle to the fan
shroud and connect the hose to the radiator filler
neck.
(16) Install the radiator upper hose and clamps.
(17) Add coolant (Refer to 7 - COOLING - STAN-
DARD PROCEDURE).
(18) Connect the battery cables.
(19) Start engine and inspect for leaks.
Fig. 123 Installing Cover with Seal Pilot
1 - SEAL PILOT
DRENGINE 5.9L DIESEL 9 - 301
GEAR HOUSING (Continued)

(d) Insert special fuel line removal tool (Snap-On
number FIH 9055-1 or equivalent) into fuel line
(Fig. 14). Use tool to release locking fingers in end
of line.
(e) With special tool still inserted, pull fuel line
from fuel rail.
(f) After disconnection, locking fingers will
remain within quick-connect fitting at end of fuel
line.
(10) Disconnect quick-connect fitting from fuel sys-
tem component being serviced.
CONNECTING
(1) Inspect quick-connect fitting body and fuel sys-
tem component for damage. Replace as necessary.
(2) Prior to connecting quick-connect fitting to
component being serviced, check condition of fitting
and component. Clean parts with a lint-free cloth.
Lubricate with clean engine oil.
(3) Insert quick-connect fitting into fuel tube or
fuel system component until built-on stop on fuel
tube or component rests against back of fitting.
(4) Continue pushing until a click is felt.
(5) Single-tab type fitting: Push new tab down
until it locks into place in quick-connect fitting.
(6) Verify a locked condition by firmly pulling on
fuel tube and fitting (15-30 lbs.).
(7) Latch Clip Equipped: Install latch clip (snaps
into position).If latch clip will not fit, this indi-
cates fuel line is not properly installed to fuel
rail (or other fuel line). Recheck fuel line con-
nection.
(8) Connect negative cable to battery.
(9) Start engine and check for leaks.
FUEL PUMP
DESCRIPTION
The electric fuel pump is located inside of the fuel
pump module. A 12 volt, permanent magnet, electric
motor powers the fuel pump. The electric fuel pump
is not a separate, serviceable component.
OPERATION
Voltage to operate the electric pump is supplied
through the fuel pump relay.
Fuel is drawn in through a filter at the bottom of
the module and pushed through the electric motor
gearset to the pump outlet.
Check Valve Operation:The bottom section of
the fuel pump module contains a one-way check
valve to prevent fuel flow back into the tank and to
maintain fuel supply line pressure (engine warm)
when pump is not operational. It is also used to keep
the fuel supply line full of gasoline when pump is not
operational. After the vehicle has cooled down, fuel
pressure may drop to 0 psi (cold fluid contracts), but
liquid gasoline will remain in fuel supply line
between the check valve and fuel injectors.Fuel
pressure that has dropped to 0 psi on a cooled
down vehicle (engine off) is a normal condition.
The electric fuel pump is not a separate, service-
able component.
FUEL PUMP MODULE
DESCRIPTION
The fuel pump module assembly is located on the
top of the fuel tank (Fig. 1). The complete assembly
contains the following components:
²A combination fuel filter/fuel pressure regulator
²A separate fuel pick-up, or inlet filter
²An electric fuel pump
²A lockring to retain pump module to tank
²A soft gasket between tank flange and module
²A fuel gauge sending unit (fuel level sensor)
²Fuel line connection
The fuel gauge sending unit may be serviced sepa-
rately. If the electrical fuel pump, primary inlet filter,
fuel filter or fuel pressure regulator require service,
the fuel pump module must be replaced.
OPERATION
Refer to Fuel Pump, Inlet Filter, Fuel Filter / Fuel
Pressure Regulator and Fuel Gauge Sending Unit.
Fig. 14 FUEL LINE DISCONNECTION USING
SPECIAL TOOL
1 - SPECIAL FUEL LINE TOOL
2 - FUEL LINE
3 - FUEL RAIL
DRFUEL DELIVERY - GAS 14 - 11
QUICK CONNECT FITTING (Continued)

FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM
The fuel system used on the Cummins engine is an
electronically controlled, Bosch HPCR (High-Pressure
Common Rail) system. The HPCR system consists of
five main components:
²Electric Fuel Transfer (lift) Pump
²Fuel Pump/Gear Pump (attached to fuel injec-
tion pump)
²High-Pressure Fuel Injection Pump
²Fuel Injection Rail
²Fuel Injectors
Also to be considered as part of the overall fuel
system are:
²Accelerator Pedal
²Air Cleaner Housing/Element
²Fuel Drain Manifold (passage)
²Fuel Drain Valve (at filter)
²Fuel Filter/Water Separator
²Fuel Heater
²Fuel Heater Relay
²Fuel Level (gauge) Sending Unit
²Fuel Pressure Limiting Valve
²Fuel Tank
²Fuel Tank Module (containing fuel gauge send-
ing unit and separate fuel filter located at bottom of
tank module)
²Fuel Tank Filler/Vent Tube Assembly
²Fuel Tank Filler Tube Cap
²Fuel Tubes/Lines/Hoses
²High-Pressure Fuel Injector Lines
²In-Tank Fuel Filter (at bottom of fuel tank mod-
ule)
²Low-Pressure Fuel Supply Lines
²Low-Pressure Fuel Return Line
²Overflow Valve
²Quick-Connect Fuel Line Fittings
²Throttle Cable
²Water Draining (maintenance)
²Water-In-Fuel (WIF) Sensor
The fuel injection pump supplies high pressure to
the fuel rail independent of engine speed. This high
pressure fuel is then accumulated in the fuel rail.
High pressure fuel is constantly supplied to the injec-
tors by the fuel rail. The Engine Control Module
(ECM) controls the fueling and timing of the engine
by actuating the injectors.Fuel enters the system from the electric fuel trans-
fer (lift) pump, which is attached to the fuel filter
assembly. Fuel is forced through the fuel filter ele-
ment and then enters the Fuel Pump/Gear Pump,
which is attached to the rear of the fuel injection
pump. The Fuel Pump/Gear Pump is a low-pressure
pump and produce pressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the
fuel injection pump. Low pressure fuel is then sup-
plied to the FCA (Fuel Control Actuator).
The FCA is an electronically controlled solenoid
valve. The ECM controls the amount of fuel that
enters the high-pressure pumping chambers by open-
ing and closing the FCA based on a demanded fuel
pressure. The FPS (Fuel Pressure Sensor) on the fuel
rail monitors the actual fuel pressure and provides it
as an input to the ECM. When the actuator is
opened, the maximum amount of fuel is being sup-
plied to the fuel injection pump. Any fuel that does
not enter the injection pump is directed to the over-
flow valve. The overflow valve regulates how much
excess fuel is used for lubrication of the pump and
how much is returned to the tank through the drain
manifold.
Fuel entering the injection pump is pressurized to
between 300-1600 bar (4351-23,206 psi) by three
radial pumping chambers. The pressurized fuel is
then supplied to the fuel rail.
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.
Certain fuel system components can be found in
(Fig. 1), or (Fig. 2).
DRFUEL DELIVERY - DIESEL 14 - 45