
LUBRICATION
DESCRIPTION
NOTE: Refer to (Fig. 148) and (Fig. 149) for circuit
illustrations.
A gear driven gerotor type oil pump is mounted
behind the front gear cover in the lower right portion
on the engine.
OPERATION
A gerotor style oil pump draws oil from the crank-
case through the suction tube and delivers it through
the block where it enters the oil cooler cover and
pressure regulator valve. When oil pressure exceeds
449 kPa (65 PSI), the valve opens exposing the dump
port, which routes excess oil back to the oil sump.
At the same time, oil is directed to a cast in pas-
sage in the oil cooler cover, leading to the oil cooler
element. As the oil travels through the element
plates, it is cooled by engine coolant traveling past
the outside of the plates. It is then routed to the oil
filter head and through a full flow oil filter. If a
plugged filter is encountered, the filter by-pass valve
opens, allowing unfiltered oil to lubricate the engine.
This condition can be avoided by frequent oil and fil-
ter changes, per the maintenance schedules found in
the owners manual. The by-pass valve is calibrated
to open when it sees a pressure drop of more than
344 kPa (50 psi) across the oil filter.The oil filter head then divides the oil between the
engine and the turbocharger. The turbocharger
receives filtered, cooled and pressurized oil through a
supply line from the filter head. The oil lubricates
the turbocharger and returns to the pan by way of a
drain tube connecting the bottom of the turbocharger
to a pressed in tube in the cylinder block.
Oil is then carried across the block to an angle
drilling which intersects the main oil rifle. The main
oil rifle runs the length of the block and delivers oil
to the crankshaft main journals and valve train. Oil
travels to the crankshaft through a series of transfer
drillings (one for each main bearing) and lubricates a
groove in the main bearing upper shell. From there
another drilling feeds the camshaft main journals.
The piston cooling nozzles are also supplied by the
main bearing upper shell. Crankshaft internal cross-
drillings supply oil to the connecting rod journals.
Another series of transfer drillings intersecting the
main oil rifle supply the valve train components. Oil
travels up the drilling, through a hole in the head
gasket, and through a drilling in the cylinder head
(one per cylinder), where it enters the rocker arm
pedestal and is divided between the intake and
exhaust rocker arm. Oil travels up and around the
rocker arm mounting bolt, and lubricates the rocker
shaft by cross drillings that intersect the mounting
bolt hole. Grooves at both ends of the rocker shaft
supply oil through the rocker arm where the oil trav-
els to the push rod and socket balls (Fig. 148) and
(Fig. 149).
9 - 292 ENGINE 5.9L DIESELBR/BE

Fig. 148 Lubrication System Circulation
1 - TO FILTER
2 - FROM FILTER
3 - TO MAIN OIL RIFLE
4 - CLOSED
5 - OPEN
6 - TO COOLER
7 - FROM PUMP8 - CLOSED
9 - OPEN
10 - TO OIL SUMP
11 - OIL DRAIN
12 - OIL SUPPLY
BR/BEENGINE 5.9L DIESEL 9 - 293
LUBRICATION (Continued)

Fig. 149 Lubrication System CirculationÐCont'd
9 - 294 ENGINE 5.9L DIESELBR/BE
LUBRICATION (Continued)

DIAGNOSIS AND TESTINGÐENGINE OIL
PRESSURE
(1) Remove the engine oil pressure sensor and
install Oil Pressure Line and Gauge Tool C-3292 with
a suitable adapter.
(2) Start engine and warm to operating tempera-
ture.
(3) Record engine oil pressure and compare with
engine oil pressure chart.
CAUTION: If engine oil pressure is zero at idle, DO
NOT RUN THE ENGINE.
Engine Oil Pressure (MIN)
At Idle 103.4 kPa (15 psi)
At 2000 rpm 310.2 kPa (45 psi)
If minimum engine oil pressure is below these
ranges, (Refer to 9 - ENGINE - DIAGNOSIS AND
TESTING).
(4) Remove oil pressure gauge and install the oil
pressure sensor. Tighten the sensor to 16 N´m (144
in. lbs.) torque.
OIL
STANDARD PROCEDURE-ENGINE OIL LEVEL
CAUTION: Do not overfill crankcase with engine oil,
oil foaming and oil pressure loss can result.
To ensure proper lubrication of an engine, the
engine oil must be maintained at an acceptable level.
The acceptable oil level is in the SAFE RANGE on
the engine oil dipstick (Fig. 150).
Unless the engine has exhibited loss of oil pres-
sure, run the engine for about five minutes before
checking oil level. Checking engine oil level of a cold
engine is not accurate.
(1) Position vehicle on level surface.
(2) With engine OFF, allow approximately ten min-
utes for oil to settle to bottom of crankcase, remove
engine oil dipstick.
(3) Wipe dipstick clean.(4)
Replace dipstick and verify it is seated in the
tube.
(5) Remove dipstick, with handle held above the
tip, take oil level reading.
(6) Add oil only if level is below the SAFE RANGE
area on the dipstick.
(7) Replace dipstick
STANDARD PROCEDURE-ENGINE OIL SERVICE
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
NOTE: Change engine oil and filter at intervals
specified in the owner's manual.
(1) Operate the engine until the water tempera-
ture reaches 60ÉC (140ÉF). Shut the engine off.
(2) Use a container that can hold at least 14 liters
(15 quarts) to hold the used oil. Remove the oil drain
plug and drain the used engine oil into the container.
(3) Always check the condition of the used oil. This
can give you an indication of engine problems that
might exist.
²Thin, black oil indicates fuel dilution.
1 - ROCKER ARM
2 - ROCKER SHAFT
3 - PEDESTAL
4 - FROM MAIN OIL RIFLE
5 - TO VALVE TRAIN
6 - MAIN OIL RIFLE
7 - FROM MAIN OIL RIFLE
8 - TO CAMSHAFT9 - TO PISTON COOLING NOZZLE
10 - FROM OIL COOLER
11 - CRANKSHAFT MAIN JOURNAL
12 - ROD JOURNAL
13 - TO ROD BEARING
14 - MAIN OIL RIFLE
Fig. 150 Oil Level Indicator (Dipstick)
1 - ADD OIL MARK
2 - O-RING
3 - SAFE RANGE
BR/BEENGINE 5.9L DIESEL 9 - 295
LUBRICATION (Continued)

²Milky discoloration indicates coolant dilution.
(4) Clean the area around the oil filter head.
Remove the filter (Refer to 9 - ENGINE/LUBRICA-
TION/OIL FILTER - REMOVAL).
(5) Install new oil filter (Refer to 9 - ENGINE/LU-
BRICATION/OIL FILTER - INSTALLATION).
(6) Clean the drain plug and the sealing surface of
the pan. Check the condition of the threads and seal-
ing surface on the oil pan and drain plug.
(7) Install the drain plug. Tighten the plug to 60
N´m (44 ft. lbs.) torque.
(8) Use only High-Quality Multi-Viscosity lubricat-
ing oil in the Cummins Turbo Diesel engine. Choose
the correct oil for the operating conditions (Refer to
LUBRICATION & MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(9) Fill the engine with the correct grade of new oil
(Refer to LUBRICATION & MAINTENANCE/FLUID
CAPACITIES - SPECIFICATIONS).
(10) Start the engine and operate it at idle for sev-
eral minutes. Check for leaks at the filter and drain
plug.
(11) Stop engine. Wait several minutes to allow the
oil to drain back to the pan and check the level
again.
USED ENGINE OIL DISPOSAL Care should be
exercised when disposing of used engine oil after
it has been drained from a vehicle's engine.
OIL COOLER & LINES
CLEANING AND INSPECTION
Clean the sealing surfaces.
Apply 483 kPa (70 psi) air pressure to the element
to check for leaks. If the element leaks, replace the
element.
OIL FILTER
REMOVAL
(1) Clean the area around the oil filter head.
Remove the filter using a 90-95 mm filter wrench.
(2) Clean the gasket surface of the filter head. The
filter canister O-Ring seal can stick on the filter
head. Make sure it is removed.
INSTALLATION
(1) Fill the oil filter element with clean oil before
installation. Use the same type oil that will be used
in the engine.
(2) Apply a light film of lubricating oil to the seal-
ing surface before installing the filter.CAUTION: Mechanical over-tightening may distort
the threads or damage the filter element seal.
(3) Install the filter until it contacts the sealing
surface of the oil filter adapter. Tighten filter an
additional ó turn.
OIL PAN
REMOVAL
(1) Disconnect the battery negative cables.
(2) Raise vehicle on hoist.
(3) Remove transmission and transfer case (if
equipped).
(4) Remove flywheel.
(5) Disconnect starter cables from starter motor.
(6) Remove starter motor (Refer to 8 - ELECTRI-
CAL/STARTING/STARTER MOTOR - REMOVAL)
and transmission adapter plate assembly.
WARNING: HOT OIL CAN CAUSE PERSONAL
INJURY.
(7) Drain the engine oil (Refer to 9 - ENGINE/LU-
BRICATION/OIL - STANDARD PROCEDURE).
(8) Install the oil pan drain plug with a new seal-
ing washer and tighten to 60 N´m (44 ft. lbs.) torque.
(9) Remove oil pan bolts, break the pan to block
seal, and lower pan slightly and remove oil suction
tube fasteners.
(10) Remove oil pan and suction tube (Fig. 151).
Fig. 151 Oil Pan, Suction Tube and Gasket
1 - GASKET
2 - SUCTION TUBE
3 - OIL PAN
9 - 296 ENGINE 5.9L DIESELBR/BE
OIL (Continued)

CLEANING
Remove all gasket material from the oil pan and
cylinder block sealing surfaces. Extra effort may be
required around T-joint areas. Clean oil pan and
flush suction tube with a suitable solvent.
INSPECTION
Inspect the oil pan, suction tube, and tube braces
for cracks and damage. Replace any defective compo-
nent. Inspect the oil drain plug and drain hole
threads. Inspect the oil pan sealing surface for
straightness. Repair any minor imperfections with a
ball-peen hammer. Do not attempt to repair an oil
pan by welding.
INSTALLATION
(1) Fill the T-joint between the pan rail/gear hous-
ing and pan rail/rear seal retainer with sealant. Use
MopartSilicone Rubber Adhesive Sealant or equiva-
lent.
(2) Place suction tube in oil pan and guide them
into place (Fig. 151). Using a new tube to oil pump
gasket, install and tighten the suction tube bolts by
hand. Starting with the oil pump inlet bolts, tighten
the bolts to 24 N´m (18 ft. lbs.) torque. Tighten the
remaining tube brace bolts to 24 N´m (18 ft. lbs.)
torque.
(3) Starting in the center and working outward,
tighten the oil pan bolts to 24 N´m (18 ft. lbs.)
torque.
(4) Install the flywheel housing assembly with the
starter motor attached and tighten bolts to 60 N´m
(44 ft. lbs.) torque.
(5) Connect starter motor cables.
(6) Install transmission and transfer case (if
equipped).
(7) Lower vehicle.
(8) Install battery negative cables.
(9) Fill the crankcase with new engine oil.
(10) Start engine and check for leaks. Stop engine,
check oil level, and adjust, if necessary.
OIL PRESSURE RELIEF VALVE
REMOVAL
(1) Disconnect the battery negative cables.
(2) Remove the threaded plug, spring and plunger
(Fig. 152). 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. 153). Replace the spring if out of limits shown
in the figure.
Fig. 152 Oil Pressure Regulator
1 - OIL FILTER
2 - PLUG
3 - GASKET
4 - SPRING
5 - VALVE
Fig. 153 Oil Pressure Regulator Spring Check
BR/BEENGINE 5.9L DIESEL 9 - 297
OIL PAN (Continued)

INSTALLATION
(1) Install the plunger, spring, and plug as shown
in (Fig. 152). Tighten the plug to 80 N´m (60 ft. lbs.)
torque.
(2) Connect the battery negative cables.
(3) Start the engine and verify that it has oil pres-
sure.
OIL PRESSURE SENSOR/
SWITCH
DESCRIPTION
The 3±wire, solid-state oil pressure sensor is
installed into the oil pressure galley on the engine
block. It is located below and to the rear of the
Engine Control Module (ECM) (Fig. 154).
OPERATION
Operation of the oil pressure sensor on the
diesel engine is controlled by the Engine Con-
trol Module (ECM). The Powertrain Control
Module (PCM) does not have any control over
the sensor.The oil pressure sensor uses three circuits. They
are:
²A 5±volt power supply from the ECM
²A sensor ground through the ECM's sensor
return
²A signal to the ECM relating to engine oil pres-
sure
The oil pressure sensor has a 3±wire electrical
function very much like the Manifold Absolute Pres-
sure (MAP) sensor on the gasoline powered engine.
Meaning different pressures relate to different output
voltages.
A 5±volt supply is sent to the sensor from the ECM
to power up the sensor. The sensor returns a voltage
signal back to the ECM relating to engine oil pres-
sure. This signal is then transferred (bussed) to the
instrument panel on the CCD bus circuit to operate
the oil pressure gauge and the check gauges lamp.
Ground for the sensor is provided by the ECM
through a low-noise sensor return.
REMOVAL
(1) Disconnect the battery negative cables.
(2) Disconnect the oil pressure sensor connector
(Fig. 155).
(3) Using a suitable socket, remove the oil pres-
sure sensor from the block (counter-clockwise).
Fig. 154 Oil Pressure Sensor (Engine) Location
1 - ENGINE OIL PRESSURE SENSOR
2 - ELECTRIAL CONNECTOR
3 - ECM
Fig. 155 Oil Pressure Sensor Location
1 - ENGINE OIL PRESSURE SENSOR
2 - ELECTRIAL CONNECTOR
3 - ECM
9 - 298 ENGINE 5.9L DIESELBR/BE
OIL PRESSURE RELIEF VALVE (Continued)

INSTALLATION
(1) If the sensor is not being replaced, inspect the
o-ring (Fig. 156) and replace if necessary.
(2) Install the oil pressure sensor and tighten to 16
N´m (144 in. lbs.) torque.
(3) Connect the battery negative cables.
(4) Start engine and check for oil leaks at the sen-
sor.
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 (Fig. 157) (Refer to
9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL).
(6) Remove the gear housing cover (Fig. 158)
(Refer to 9 - ENGINE/VALVE TIMING/GEAR HOUS-
ING COVER - REMOVAL).
(7) Remove the four mounting bolts and pull the
pump from the bore in the cylinder block (Fig. 159).
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. 160).
(3) Mark TOP on the gerotor planetary using a felt
tip pen (Fig. 160).
(4) Remove the gerotor planetary (Fig. 160).
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. The chamfer must be on the O.D. and down.
Fig. 156 Oil Pressure Sensor and
1 - ENGINE OIL PRESSURE SENSOR
2 - O-RING
Fig. 157 Crankshaft Damper Removal/Installation
1 - DAMPER
2 - BOLT
Fig. 158 Gear Housing and Cover
1 - GEAR HOUSING
2 - GEAR HOUSING COVER
BR/BEENGINE 5.9L DIESEL 9 - 299
OIL PRESSURE SENSOR/SWITCH (Continued)