
(9) If required, adjust spark plugs to specifications.
Install the plugs and tighten to 41 N´m (30 ft. lbs.)
torque.
(10) Install coil wire.
(11) Connect heat indicator sending unit wire.
(12) Connect the heater hoses and bypass hose.
(13) Install distributor cap and wires.
(14) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(15) Install the fuel supply line (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/QUICK CON-
NECT FITTING - STANDARD PROCEDURE).
(16) Install the generator and drive belt (Refer to 7
- COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION). Tighten generator mounting bolt
to 41 N´m (30 ft. lbs.) torque. Tighten the adjusting
strap bolt to 23 N´m (200 in. lbs.) torque.
(17) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts.
(18) Place the cylinder head cover gaskets in posi-
tion and install cylinder head covers (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(19) Install closed crankcase ventilation system.
(20) Connect the evaporation control system.
(21) Install the air cleaner.
(22) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(23) Connect the negative cable to the battery.
(24) Start engine check for leaks.
CYLINDER HEAD COVER(S)
REMOVAL
NOTE: A steel backed silicon gasket is used with
the cylinder head cover (Fig. 7). This gasket can be
used again.
(1) Disconnect the negative cable from the battery.(2) Disconnect the spark plug wires form the spark
plugs and set aside.
(3) Disconnect closed ventilation system and evap-
oration control system from cylinder head cover.
(4) Remove cylinder head cover and gasket.
CLEANING
Clean cylinder head cover gasket surface.
Clean head rail, if necessary.
INSPECTION
Inspect cover for distortion and straighten, if nec-
essary.
Check the gasket for use in head cover installation.
If damaged, use a new gasket.
INSTALLATION
(1) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.
(2) Position the cylinder head cover onto the gas-
ket. Tighten the bolts to 11 N´m (95 in. lbs.) torque.
(3) Install closed crankcase ventilation system and
evaporation control system.
(4)
Connect the spark plug wires to the spark plugs.
(5) Connect the negative cable to the battery.
INTAKE/EXHAUST VALVES &
SEATS
DESCRIPTION
Both the intake and exhaust valves are made of
steel. The intake valve is 48.768 mm (1.92 inches) in
diameter and the exhaust valve is 41.148 mm (1.62
inches) in diameter and has a 2.032 mm (0.080 inch)
wafer interia welded to the tip for durability. These
valves are not splayed.
STANDARD PROCEDUREÐVALVES, GUIDES
AND SPRINGS
VALVE CLEANING
Clean valves thoroughly. Discard burned, warped,
or cracked valves.
Remove carbon and varnish deposits from inside of
valve guides with a reliable guide cleaner.
VALVE GUIDES
Measure valve stems for wear. If wear exceeds
0.051 mm (0.002 in.), replace the valve.
Measure valve stem guide clearance as follows:
(1) Install Valve Guide Sleeve Tool C-3973 over
valve stem and install valve (Fig. 8). The special
sleeve places the valve at the correct height for
checking with a dial indicator.
Fig. 7 Cylinder Head Cover Gasket
1 - CYLINDER HEAD COVER GASKET
9 - 138 ENGINE 5.9LBR/BE
CYLINDER HEAD (Continued)

The relief valve spring has a free length of approx-
imately 49.5 mm (1.95 inches). The spring should
test between 19.5 and 20.5 pounds when compressed
to 34 mm (1-11/32 inches). Replace spring that fails
to meet these specifications (Fig. 63).
If oil pressure was low and pump is within specifi-
cations, inspect for worn engine bearings or other
reasons for oil pressure loss.
ASSEMBLE
(1) Install pump rotors and shaft, using new parts
as required.
(2)
Position the oil pump cover onto the pump body.
Tighten cover bolts to 11 N´m (95 in. lbs.) torque.
(3) Install the relief valve and spring. Insert the
cotter pin.
(4) Tap on a new retainer cap.
(5) Prime oil pump before installation by filling
rotor cavity with engine oil.
INSTALLATION
(1) Install oil pump. During installation slowly
rotate pump body to ensure driveshaft-to-pump rotor
shaft engagement.
(2) Hold the oil pump base flush against mating
surface on No.5 main bearing cap. Finger tighten
pump attaching bolts. Tighten attaching bolts to 41
N´m (30 ft. lbs.) torque.
(3) Install the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION).
INTAKE MANIFOLD
DESCRIPTION
The aluminum intake manifold (Fig. 64) is a single
plane design with equal length runners and uses aseparate plenum, therefore the manifold does have a
plenum gasket. It also uses separate flange gaskets
and front and rear cross-over gaskets. Extreme care
must be used when sealing the gaskets to ensure
that excess sealant does not enter the intake runners
causing a restriction. Whenever the intake manifold
is removed inspect the plenum pan for evidence of
excess oil buildup, this condition indicates that the
plenum pan gasket is leaking.
OPERATION
The intake manifold, meters and delivers air to the
combustion chambers allowing the fuel delivered by
the fuel injectors to ignite, thus producing power.
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.
Fig. 63 Proper Installation of Retainer Cap
1 - RETAINER CAP
2 - CHAMFER
3 - COTTER KEY
Fig. 64 Intake Manifold and Throttle BodyÐV-8 Gas
Engines Typical
1 - FUEL RAIL ASSEMBLY
2 - FUEL RAIL MOUNTING BOLTS
3 - FUEL RAIL CONNECTING HOSES
BR/BEENGINE 5.9L 9 - 165
OIL PUMP (Continued)

(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 A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - REMOVAL).
(4) Remove the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - REMOVAL).
(5) Remove the accessory drive bracket.
(6) Remove the air cleaner.
(7) Perform the Fuel System Pressure release pro-
cedure (Refer to 14 - FUEL SYSTEM/FUEL DELIV-
ERY - STANDARD PROCEDURE). Disconnect the
fuel lines (Refer to 14 - FUEL SYSTEM/FUEL
DELIVERY/QUICK CONNECT FITTING - STAN-
DARD PROCEDURE).
(8) Disconnect the accelerator linkage (Refer to 14
- FUEL SYSTEM/FUEL INJECTION/THROTTLE
CONTROL CABLE - REMOVAL) and if so equipped,
the speed control and transmission kickdown cables.
(9) Remove the return spring.
(10) Remove the distributor cap and wires.
(11) Disconnect the coil wires.
(12) Disconnect the heat indicator sending unit
wire.
(13) Disconnect the heater hoses and bypass hose.
(14) Remove the closed crankcase ventilation and
evaporation control systems.
(15) Remove intake manifold bolts.
(16) Lift the intake manifold and throttle body out
of the engine compartment as an assembly.
(17) Remove and discard the flange side gaskets
and the front and rear end seals.
(18) Remove the throttle body bolts and lift the
throttle body off the intake manifold (Fig. 65). Dis-
card the gasket.
(19) If required, remove the plenum pan and gas-
ket. Discard gasket.
CLEANING
Clean manifold in solvent and blow dry with com-
pressed air.
Clean cylinder block front and rear gasket surfaces
using a suitable solvent.
The plenum pan rail must be clean and dry (free of
all foreign material).
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straightedge.
INSTALLATION
(1) If removed, position new plenum gasket and
install plenum pan (Fig. 66).
(2) Tighten plenum pan mounting bolts as follows:
²Step 1. Tighten bolts to 5.4 N´m (48 in. lbs.)
²Step 2. Tighten bolts to 9.5 N´m (84 in. lbs.)
²Step 3. Check all bolts are at 9.5 N´m (84 in.
lbs.)
Fig. 65 Throttle Body Assembly
1 - FUEL RAIL ASSEMBLY
2 - FUEL RAIL MOUNTING BOLTS
3 - FUEL RAIL CONNECTING HOSES
Fig. 66 Plenum Pan Bolt Tightening Sequence
9 - 166 ENGINE 5.9LBR/BE
INTAKE MANIFOLD (Continued)

(9) Install closed crankcase ventilation and evapo-
ration control systems.
(10) Connect the coil wires.
(11) Connect the heat indicator sending unit wire.
(12) Connect the heater hoses and bypass hose.
(13) Install distributor cap and wires.
(14) Hook up the return spring.
(15) Connect the accelerator linkage (Refer to 14 -
FUEL SYSTEM/FUEL INJECTION/THROTTLE
CONTROL CABLE - INSTALLATION) and if so
equipped, the speed control and transmission kick-
down cables.
(16) Install the fuel lines (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(17) Install the accessory drive bracket and A/C
compressor (Refer to 24 - HEATING & AIR CONDI-
TIONING/PLUMBING/A/C COMPRESSOR -
INSTALLATION).
(18) Install the generator and drive belt (Refer to 7
- COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION). Tighten generator mounting bolt
to 41 N´m (30 ft. lbs.) torque.
(19) Install the air cleaner.
(20) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(21) Connect the negative cable to the battery.
EXHAUST MANIFOLD
DESCRIPTION
The exhaust manifolds (Fig. 70) are constructed of
cast iron and are LOG type with balanced flow. One
exhaust manifold is attached to each cylinder head.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise and support the vehicle.
(3) Remove the bolts and nuts attaching the
exhaust pipe to the engine exhaust manifold.
(4) Lower the vehicle.
(5) Remove the exhaust heat shields.
(6) Remove bolts, nuts and washers attaching
manifold to cylinder head.
(7) Remove manifold from the cylinder head.
CLEANING
Clean mating surfaces on cylinder head and mani-
fold. Wash with solvent and blow dry with com-
pressed air.
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straight edge. Gasket surfaces must be flat
within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
CAUTION: If the studs came out with the nuts when
removing the engine exhaust manifold, install new
studs. Apply sealer on the coarse thread ends.
Water leaks may develop at the studs if this precau-
tion is not taken.
(1) Position the engine exhaust manifolds on the
two studs located on the cylinder head. Install coni-
cal washers and nuts on these studs (Fig. 71).
(2) Install two bolts and conical washers at the
inner ends of the engine exhaust manifold outboard
arms. Install two bolts WITHOUT washers on the
center arm of engine exhaust manifold (Fig. 71).
Starting at the center arm and working outward,
tighten the bolts and nuts to 34 N´m (25 ft. lbs.)
torque.
(3) Install the exhaust heat shields.
(4) Raise and support the vehicle.
(5) Assemble exhaust pipe to manifold and secure
with bolts, nuts and retainers. Tighten the bolts and
nuts to 34 N´m (25 ft. lbs.) torque.
Fig. 70 Exhaust ManifoldsÐV-8 Gas Engines Typical
1 - EXHAUST MANIFOLD (LEFT)
2 - BOLTS & WASHERS
3 - NUTS & WASHERS
4 - EXHAUST MANIFOLD (RIGHT)
5 - BOLTS & WASHERS
9 - 168 ENGINE 5.9LBR/BE
INTAKE MANIFOLD (Continued)

(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)

DIAGNOSIS AND TESTINGÐENGINE DIAGNOSIS - MECHANICAL
CONDITION POSSIBLE CAUSES CORRECTION
LUBRICATING OIL
PRESSURE LOW1. Low oil level. 1. (a) Check and fill with clean engine oil.
(b) Check for a severe external oil leak that
could reduce the pressure.
2. Oil viscosity thin, diluted or wrong
specification.2. Verify the correct engine oil is being
used. (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
3. Improperly operating pressure
switch/gauge.3. Verify the pressure switch is functioning
correctly. If not, replace switch/gauge.
4. Relief valve stuck open. 4. Check/replace valve.
5. Plugged oil filter. 5. Change oil filter.
6. If cooler was replaced, shipping
plugs may have been left in cooler6. Check/remove shipping plugs.
7. Worn oil pump. 7. Check and replace oil pump.
8. Suction tube loose or seal leaking. 8. Check and replace seal.
9. Loose main bearing cap. 9. Check and install new bearing. Tighten
cap to proper torque.
10. Worn bearings or wrong bearings
installed.10. Inspect and replace connecting rod or
main bearings. Check and replace piston
cooling nozzles.
11. Oil jet under piston bad fit into
main carrier.11. Check oil jet position.
LUBRICATING OIL
PRESSURE TOO HIGH1. Pressure switch/gauge not
operating properly.1. Verify pressure switch is functioning
correctly. If not, replace switch/gauge.
2. Engine running to cold. 2. Refer to Coolant Temperature Below
Normal (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING).
3. Oil viscosity too thick. 3. Make sure the correct oil is being used.
(Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
4. Oil pressure relief valve stuck
closed or binding4. Check and replace valve.
LUBRICATING OIL LOSS 1. External leaks. 1. Visually inspect for oil leaks. Repair as
required.
2. Crankcase being overfilled. 2. Verify that the correct dipstick is being
used.
3. Incorrect oil specification or
viscosity.3. (a) Make sure the correct oil is being
used (Refer to LUBRICATION &
MAINTENANCE/FLUID TYPES -
DESCRIPTION).
(b) Look for reduced viscosity from dilution
with fuel.
(c) Review/reduce oil change intervals.
9 - 232 ENGINE 5.9L DIESELBR/BE
ENGINE 5.9L DIESEL (Continued)

REMOVALÐCRANKCASE BREATHER VAPOR
CANISTER
NOTE: It is recommended to empty the contents of
the vapor canister at each oil and filter service
interval.
(1) Loosen cap from top of vapor canister.
(2) Remove nut retaining canister to engine front
cover.
(3) Slide clamp upwards on hose, then remove
hose from crankcase breather.
INSTALLATIONÐENGINE
(1) Install the engine with the cylinder head cover
and the #5 and 6 rocker arm assemblies removed.
(2) Lower the engine into the compartment and
install the engine mount through bolts and nuts.
(3) Tighten the mount through bolts and nuts to
88 N´m (65 ft. lbs.) torque.
(4) Remove the engine lifting device.
(5) Install the #5 and #6 rocker arms and pedes-
tals in their original locations (Fig. 8). Torque the
mounting bolts to 36 N´m (27 ft. lbs.) torque.
(6) Install the cylinder head cover and gasket
(Refer to 9 - ENGINE/CYLINDER HEAD - INSTAL-
LATION).
(7) Connect the fuel supply and return hoses (Fig.
7).
(8) Connect the engine harness connector and
ground cable to the PDC.
(9) Connect the vacuum pump supply hose.(10) Connect the APPS connector (Fig. 5).
(11) Install the APPS assembly bracket to the cyl-
inder head bracket.
(12) Install the throttle linkage cover.
(13) Connect the power steering pressure and
return lines.
(14) Connect the passenger battery ground cable to
the engine block. Tighten the bolt to 77 N´m (57 ft.
lbs.) torque.
(15) Connect the engine block heater connector.
(16) Connect the a/c compressor electrical connec-
tors.
(17) Install the charge air cooler and a/c condenser
(if a/c equipped). Install and tighten the charge air
cooler mounting bolts to 2 N´m (17 in. lbs.) torque.
(18) Connect the charge air cooler piping. Torque
all clamps to 8 N´m (72 in. lbs.) torque.
(19) Connect the a/c refrigerant lines to the a/c
condenser (if equipped).
(20) Install the front bumper (Refer to 13 -
FRAMES & BUMPERS/BUMPERS/FRONT
BUMPER - INSTALLATION).
(21) Install the radiator upper support panel.
(22) Install the radiator (Refer to 7 - COOLING/
ENGINE/RADIATOR - INSTALLATION).
Fig. 8 Rocker Arm and PedestalÐRemoval/
Installation
1 - ROCKER ARM
2 - PEDESTALFig. 9 Crankcase Breather Vapor Canister
1 - ENGINE FRONT COVER STUD
2 - STRAP
3 - VAPOR CANISTER
4 - NUT
5 - CAP
6 - CRANKCASE BREATHER
7 - CLAMP
8 - HOSE
BR/BEENGINE 5.9L DIESEL 9 - 241
ENGINE 5.9L DIESEL (Continued)