
(1) After installing housing, tighten 4 nuts to 11
N´m (96 in. lbs.) torque and connect crankcase vent
hose.
(2) Position air cleaner element (filter) into air
cleaner cover. Latch spring clips to seal cover to
housing.
(3) Install air inlet tube at air cleaner housing
inlet.
(4) Install and tighten clamp at air inlet tube (Fig.
6).
CYLINDER HEAD
DESCRIPTION
The alloy cast iron cylinder heads (Fig. 7) are held
in place by 12 bolts. The spark plugs are located in
the peak of the wedge between the valves.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET FAILURE
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
²Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
²Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test in this
section. An engine cylinder head gasket leaking
between adjacent cylinders will result in approxi-
mately a 50±70% reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
Fig. 6 Clamp InstallationÐ8.0L Engine
1 - CLAMP
2 - ADJUSTABLE PLIERS
Fig. 7 Cylinder Head Assembly
1 - SPARK PLUG
2 - INTAKE VALVES
3 - SPARK PLUG
4 - INTAKE VALVES
5 - SPARK PLUG
6 - SPARK PLUG
7 - INTAKE VALVE
8 - SPARK PLUG
9 - EXHAUST VALVE
10 - EXHAUST VALVES
11 - EXHAUST VALVES
BR/BEENGINE 8.0L 9 - 191
AIR CLEANER ELEMENT (Continued)

COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(3) Remove the heat shields (Fig. 8).
(4) Remove the intake manifold-to-generator
bracket support rod. Remove the generator (Refer to
8 - ELECTRICAL/CHARGING/GENERATOR -
REMOVAL).
(5) Remove closed crankcase ventilation system.
(6) Disconnect the evaporation control system.
(7) Remove the air cleaner.
(8) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-ERY - STANDARD PROCEDURE). Disconnect the
fuel line (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY/QUICK CONNECT FITTING - STANDARD
PROCEDURE).
(9) Disconnect accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(10) Remove coil pack and bracket (Fig. 9).
(11) Disconnect the coil wires.
(12) Disconnect heat indicator sending unit wire.
(13) Disconnect heater hoses and bypass hose.
(14) Remove upper intake manifold and throttle
body as an assembly (Refer to 9 - ENGINE/MANI-
FOLDS/INTAKE MANIFOLD - REMOVAL).
(15) Remove cylinder head covers and gaskets
(Refer to 9 - ENGINE/CYLINDER HEAD/CYLIN-
DER HEAD COVER(S) - REMOVAL).
(16) Remove the EGR tube. Discard the gasket, for
right side only.
(17) Remove lower intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL). Discard the flange side gaskets and the
front and rear cross-over gaskets.
(18) Disconnect exhaust pipe from exhaust mani-
fold.
(19) Remove exhaust manifolds and gaskets (Refer
to 9 - ENGINE/MANIFOLDS/EXHAUST MANIFOLD
- REMOVAL).
(20) Remove rocker arm assemblies and push rods
(Refer to 9 - ENGINE/CYLINDER HEAD/ROCKER
Fig. 8 Spark Plug Wire Heat Shields (Left Side
Shown)
1 - EXHAUST MANIFOLD
2 - HEAT SHIELD
Fig. 9 Coil Pack and Bracket
1 - COIL PACKS AND BRACKET
2 - MOUNTING BOLTS (4)
9 - 192 ENGINE 8.0LBR/BE
CYLINDER HEAD (Continued)

(2) Position the oil pump cover onto the timing
chain cover. Tighten cover screws to 14 N´m (125 in.
lbs.) torque.
(3) Make sure that inner ring moves freely after
cover is installed.
(4) Install the timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(5) Squirt oil into relief valve hole until oil runs
out.
(6) Install the relief valve and spring.
(7) Using a new pressure relief valve gasket,
install the relief valve plug. Tighten the plug to 20
N´m (15 ft. lbs.) torque.
(8) Install oil filter that has been filled with oil.
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 68) has two
plenum chambers an upper and lower which supply
air to five runners each. Passages across the longitu-
dinal center of the manifold feed air from the throttle
body to the plenum chambers.
DIAGNOSIS AND TESTINGÐINTAKE
MANIFOLD LEAKAGE
An intake manifold air leak is characterized by
lower than normal manifold vacuum. Also, one or
more cylinders may not be functioning.
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING. DO NOT STAND IN A
DIRECT LINE WITH THE FAN. DO NOT PUT YOUR
HANDS NEAR THE PULLEYS, BELTS, OR THE FAN.
DO NOT WEAR LOOSE CLOTHING.
(1) Start the engine.
(2) Spray a small stream of water at the suspected
leak area.
(3) If a change in RPMs occurs, the area of the
suspected leak has been found.
(4) Repair as required.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Drain the cooling system (Refer to 7 - COOL-
ING - STANDARD PROCEDURE).
(3) Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL).
(4) Remove the generator brace and generator
(Fig. 69).
(5) Remove the A/C compressor brace (Fig. 69).
Remove the compressor and set aside.
Fig. 68 Upper and Lower Intake ManifoldÐ8.0L
Engine
1 - UPPER INTAKE MANIFOLD
2 - THROTTLE BODY (MPI)
3 - LOWER INTAKE MANIFOLD
Fig. 69 Generator and A/C Compressor Braces
1 - GENERATOR
2 - INTAKE MANIFOLD TO GENERATOR BRACE
3 - A/C COMPRESSOR
4 - INTAKE MANIFOLD TO A/C COMPRESSOR BRACE
9 - 222 ENGINE 8.0LBR/BE
OIL PUMP (Continued)

INSPECTIONÐCYLINDER HEAD
Inspect the cylinder head for cracks in the combus-
tion surface. Pressure test any cylinder head that is
visibly cracked. A cylinder head that is cracked
between the injector bore and valve seat can be pres-
sure tested and reused if OK; however, if the crack
extendsintothe valve seat, the valve seatmustbe
replaced.
Visually inspect the cylinder block and head com-
bustion surfaces for localized dips or imperfections.
Check the cylinder head and block combustion sur-
faces for overall out-of-flatness. If either the visual or
manual inspection exceeds the limits, then the head
or block must be surfaced.
Check the top surface for damage caused by the
cylinder head gasket leaking between cylinders.
Inspect the block and head surface for nicks, ero-
sion, etc.
Check the head distortion (Fig. 25). The distortion
of the combustion deck face is not to exceed 0.010
mm (0.0004 inch) in any 50.8 mm (2.00 inch) diame-
ter. Overall variation end to end or side to side 0.30
mm (0.012 inch).
DO NOT proceed with the in-chassis overhaul if
the cylinder head or block surface is damaged or not
flat (within specifications).
Visually inspect the cylinder head bolts for dam-
aged threads, corroded/pitted surfaces, or a reduced
diameter due to bolt stretching.
If the bolts are not damaged, their ªfree lengthº
should be measured using the cap screw stretch
gauge provided with the replacement head gasket.
Place the head of the bolt against the base of the slot
and align the bolt with the straight edge of gauge
(Fig. 26). If the end of the bolt touches the foot of the
gauge, the boltmustbe discarded.The maximum
bolt free length is 132.1 mm (5.200 in.).
INSPECTIONÐCROSSHEADS
Inspect the crossheads for cracks and/or excessive
wear on rocker lever and valve tip mating surfaces
(Fig. 27). Replace any crossheads that exhibit abnor-
mal wear or cracks.
INSPECTIONÐPUSHRODS
Inspect the push rod ball and socket for signs of
scoring. Check for cracks where the ball and the
socket are pressed into the tube (Fig. 28).
Roll the push rod on a flat work surface with the
socket end hanging off the edge (Fig. 29). Replace
any push rod that appears to be bent.
INSTALLATION
WARNING: THE OUTSIDE EDGE OF THE HEAD
GASKET IS VERY SHARP. WHEN HANDLING THE
NEW HEAD GASKET, USE CARE NOT TO INJURE
YOURSELF.
(1) Install a new gasket with the part number side
up, and locate the gasket over the dowel sleeves.
(2) Using an engine lifting crane, lower the cylin-
der head onto the engine.
Fig. 25 Cylinder Head Combustion Deck Face
1 - STRAIGHT EDGE
2 - FEELER GAUGE
Fig. 26 Head Bolt Stretch Gauge
Fig. 27 Inspecting Crosshead for Cracks
9 - 250 ENGINE 5.9L DIESELBR/BE
CYLINDER HEAD (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)

(3)Pre-lube the turbocharger.Pour 50 to 60 cc
(2 to 3 oz.) clean engine oil in the oil supply line fit-
ting. Carefully rotate the turbocharger impeller by
hand to distribute the oil thoroughly.
(4) Install and tighten the oil supply line fitting
nut to 20 N´m (133 in. lbs.) torque.
(5) Position the charge air cooler inlet pipe to the
turbocharger. With the clamp in position, tighten the
clamp nut to 11 N´m (95 in. lbs.) torque.
(6) Position the air inlet hose to the turbocharger
(Fig. 23). Tighten the clamp to 11 N´m (95 in. lbs.)
torque.
(7) Raise vehicle on hoist.
(8) Connect the exhaust pipe to the turbocharger
(Fig. 22) and tighten the bolts to 34 N´m (25 ft. lbs.)
torque.
(9) Lower the vehicle.
(10) Connect the battery negative cables.
(11) Start the engine to check for leaks.
CHARGE AIR COOLER AND
PLUMBING
DESCRIPTION
The charge air system (Fig. 28) consists of the
charge air cooler piping, charge air cooler and intake
air grid heater.
The charge air cooler is a heat exchanger that uses
air flow from vehicle motion to dissipate heat from
the intake air. As the turbocharger increases air
pressure, the air temperature increases. Lowering
the intake air temperature increases engine effi-
ciency and power.
OPERATION
Intake air is drawn through the air cleaner and
into the turbocharger compressor housing. Pressur-
ized air from the turbocharger then flows forward
through the charge air cooler located in front of the
radiator. From the charge air cooler the air flows
back into the intake manifold.
REMOVAL
WARNING: IF THE ENGINE WAS JUST TURNED
OFF, THE AIR INTAKE SYSTEM TUBES MAY BE
HOT.
(1) Disconnect the battery negative cables.
(2) Remove the front bumper (Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - REMOVAL).
Fig. 26 Measure Turbocharger Axial End Play
Fig. 27 Measure Turbocharger Bearing Radial
Clearance
1 - FEELER GAUGE
Fig. 28 Intake Air Circulation
1 - CHARGE AIR COOLER
2 - AIRFILTER
3 - TURBOCHARGER
BR/BEEXHAUST SYSTEM 11 - 17
TURBOCHARGER (Continued)

FRAME
DESCRIPTION
The BR/BE frame is the structural center of the
vehicle. In addition to supporting the body and pay-
load, the frame provides a station for the engine and
drivetrain. BR/BE trucks have a ladder type frame
with Box-section front rails, dropped center section,
and open-channel side rails in the rear.
Cross members attach to the side rails with rivets,
welds, or bolts. The cab is isolated from the frame
with rubber load cushions with through bolts. The
cargo box or bed is attached to the frame with bolts.
The frame is designed to absorb and dissipate flex-
ing and twisting due to acceleration, braking, corner-
ing, and road surface variances without bending
when subjected to normal driving conditions.
FRAME SERVICE
SAFETY PRECAUTIONS AND WARNINGS
WARNING: USE EYE PROTECTION WHEN GRIND-
ING OR WELDING METAL, SERIOUS EYE INJURY
CAN RESULT. BEFORE PROCEEDING WITH FRAME
REPAIR INVOLVING GRINDING OR WELDING, VER-
IFY THAT VEHICLE FUEL SYSTEM IS NOT LEAKING
OR IN CONTACT WITH REPAIR AREA, PERSONAL
INJURY CAN RESULT. DO NOT ALLOW OPEN
FLAME TO CONTACT PLASTIC BODY PANELS.
FIRE OR EXPLOSION CAN RESULT. WHEN
WELDED FRAME COMPONENTS ARE REPLACED,
100% PENETRATION WELD MUST BE ACHIEVED
DURING INSTALLATION. IF NOT, DANGEROUS
OPERATING CONDITIONS CAN RESULT. STAND
CLEAR OF CABLES OR CHAINS ON PULLING
EQUIPMENT DURING FRAME STRAIGHTENING
OPERATIONS, PERSONAL INJURY CAN RESULT.
DO NOT VENTURE UNDER A HOISTED VEHICLE
THAT IS NOT SUPPORTED ON SAFETY STANDS,
PERSONAL INJURY CAN RESULT.
Fig. 8 Rear Bumper
1 - INNER BRACKET
2 - BUMPER3 - OUTER BRACKET
13 - 6 FRAME & BUMPERSBR/BE
REAR BUMPER (Continued)