33. Raise and support the vehicle.
34. Connect the hydraulic lines to the fan assembly and steering rack then connect the A/C hose to the fan shroud.
35. Install aNewoil filter.
36. Lower the vehicle.
37. Install upper radiator hose and connect the ground wire at the thermostat housing.
38. Install air cleaner housing cover assembly, connect throttle body airinlet duct, IAT sensor and CCV hose. (Refer
to 9 - ENGINE/AIR INTAKE SYSTEM - INSTALLATION).
39. Fill and purge air from the power steering system.
40. Fill engine crankcase with proper oil to correct level.
41. Fill and purge air from the cooling system (Refer to 7 - COOLING/ENGINE -STANDARD PROCEDURE - FILL-
ING COOLING SYSTEM).
42. Connect negative battery cable.
43. Start the vehicle and inspect for leaks.
44. Install the lower engine shield.
LUBRICATION
DESCRIPTION
The engine lubrication system is a full-flow filtration pressure feed type.
OPERATION
Engine oil stored in the oil pan is taken in and discharged by an internal geartypeoilpump,whichisdrivenbythe
crankshaft. A pressure relief valve is located in the timing chain case cover; it regulates oil pressure. The oil is
pumped through an oil filter and feeds a main oil gallery. Also, oil is routedtoanexternaloilcooler.Themainoil
gallery feeds oil under pressure to the main bearings, connecting rod bearings, and camshaft bearings. Passages in
the cylinder block feed oil to the hydraulic lifters. The oil then flows through hollow pushrods, which feed the rocker
arm pivots.
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
1. Remove oil pressure sensor (Refer to 9 - ENGINE/LUBRICATION/OIL PRESSURE SENSOR - REMOVAL).
2. Install oil pressure gauge.
3. Warm engine at high idle until thermostat opens.
CAUTION: If oil pressure is 0 at idle, Do Not Run engine at 3000 RPM.
4. Oil pressure should be 68.9 kPa (10 psi) at idle or 310 - 517 kPa (45 - 75 psi)at 3000 RPM.
5. If oil pressure is 0 at idle, shut off engine. Check for a clogged oil pick-up screen or a pressure relief valve stuck
open.
ENGINE OIL LEAK
Begin with a thorough visual inspection of the engine, particularly at thearea of the suspected leak. If an oil leak
source is not readily identifiable, thefollowingstepsshouldbefollowed:
1. Do not clean or degrease the engine at this time because some solvents maycause rubber to swell, temporarily
stopping the leak.
2. Add an oil soluble dye (use as recommended by manufacturer). Start the engine and let idle for approximately 15
minutes. Check the oil dipstick to make sure the dye is thoroughly mixed as indicated with a bright yellow color
under a black light.
3. Using a black light, inspect the entire engine for fluorescent dye, particularly at the suspected area of oil leak. If
the oil leak is found and identified, repair per service manual instructions.
4. If dye is not observed, drive the vehicle at various speeds for approximately 24 km (15 miles), and repeat inspec-
tion.If the oil leak source is not positively identified at this time, proceed with the air leak detection test
method.
Air Leak Detection Test Method
1. Remove the PCV valve from the IAFM. Cap or plug the PCV valve grommet.
2. Attach an air hose with pressure gauge and regulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to more than 20.6 kPa (3 PSI) of test pressure.
3. Gradually apply air pressure from 6.89 - 17.23 kPa (1 - 2.5 psi) maximum while applying soapy water at the
suspected source. Adjust the regulator to the suitable test pressure thatprovide the best bubbles which will pin-
point the leak source. If the oil leak is detected and identified, repair per service manual procedures.
4. If the leakage occurs at the rear oil seal area, refer to the section, Inspection for Rear Seal Area Leak.
5. If no leaks are detected, turn off the air supply and remove the air hose and all plugs and caps. Install the PCV
valve.
6. Clean the oil off the suspect oil leak area using a suitable solvent. Drive the vehicle at various speeds approx-
imately 24 km (15 miles). Inspect the engine for signs of an oil leak by usinga black light.
THROTTLE BODY
DESCRIPTION
The throttle body is located on the intake manifold. Fuel does not enter theintake manifold through the throttle body.
Fuel is sprayed into the manifold by the fuel injectors.
OPERATION
Filtered air from the air cleaner enters the intake manifold through the throttle body. The throttle body contains an air
control passage controlled by an Idle Air Control (IAC) motor. The air control passage is used to supply air for idle
conditions. A throttle valve (plate) is used to supply air for above idle conditions.
5.7L V-8 Engine:
The throttle body on the 5.7L engine is an electrically controlled unit. A mechanical cable is not used to connect the
throttle body to the accelerator pedal. The Accelerator Pedal Position Sensor (APPS) along with inputs from other
sensors sets the throttle blade to pre-determined positions.
Except 5.7L V-8 Engine:
Certain sensors are attached to the throttle body. The accelerator pedal cable, speed control cable and transmission
control cable (when equipped) are connected to the throttle body linkage arm.
A (factory adjusted) set screw is usedto mechanically limit the position of the throttle body throttle plate.Never
attempt to adjust the engine idle speed using this screw.All idle speed functions are controlled by the PCM.
REMOVAL
3.7L V-6
A (factory adjusted) set screw is used to mechanically
limit the position of the throttle body throttle plate.
Never attempt to adjust the engine idle speed
using this screw.All idle speed functions are con-
trolled by the Powertrain Control Module (PCM).
1. Remove air cleaner tube at throttle body.
2. Disconnect throttle body electrical connectors at
IAC motor and TPS.
3. Remove all control cables from throttle body (lever)
arm. Refer to the Accelerator Pedal and Throttle
Cable section for removal/installation procedures.
4. Disconnect necessary vacuum lines at throttle
body.
5. Remove 3 throttle body mounting bolts (2).
6. Remove throttle body from intake manifold.
FUEL DELIVERY - DIESEL
DESCRIPTION - DIESEL FUEL SYSTEM
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.
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:
Electric Fuel Transfer (lift) Pump Located in the Fuel Tank
Fuel Pump/Gear Pump (attached to fuel injection pump)
High-Pressure Fuel Injection Pump
Fuel Injection Rail
Fuel Injectors
Also to be considered as part of the overall fuel system are:
Accelerator Pedal
Air Cleaner Housing/Element
Check Valve Banjo Fitting at Rear of Cylinder Head
Fuel Connector Tubes
Fuel Drain Manifold (passage)
Fuel Drain Valve (at filter)
Fuel Filter/Water Separator
Fuel Heater
Fuel Heater Relay
Fuel Transfer Pump Relay
Fuel Level (gauge) Sending Unit
Fuel Pressure Limiting Valve
Fuel Tank
Fuel Tank Module (containing a fuel gauge sending unit, separate fuel filter located at bottom of tank module,
and fuel transfer pump)
Fuel Tank Filler/Vent Tube Assembly
Fuel Tank Filler Tube Cap
Fuel Tubes/Lines/Hoses
High-Pressure Fuel Injector Lines
In-Tank Fuel Filter (at bottom of fuel tank module)
Low-Pressure Fuel Supply Lines
Low-Pressure Fuel Return Lines
Overflow Valve
Quick-Connect Fuel Line Fittings
Accelerator Pedal Position Sensor (APPS) Located in Cab
Water Draining (maintenance)
Water-In-Fuel (WIF) Sensor
Screened Banjo Bolt (22)
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 injectors 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 transfer (lift) pump, which is located inside of the fuel tank and attached
to the fuel tank module (the fuel transfer pump is no longer attached to the engine). Fuel is forced through the fuel
filter element 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 supplied 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 opening 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 supplied to the fuel injection pump. Any fuel that does
not enter the injection pump is directed to the overflow 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.
STANDARD PROCEDURE
WATER DRAINING AT FUEL FILTER
Refer to Fuel Filter/Water Separatorremoval/installation for procedures.
CLEANING FUEL SYSTEM PARTS
CAUTION: Cleanliness cannot be overemphasized when handling or replacingdieselfuelsystemcompo-
nents. 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 possible 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. Capor cover any open part after
disassembly. Before assembly, examine each part for dirt, grease or othercontaminants and clean if nec-
essary. When installing new parts, lubricate them with clean engine oil orclean diesel fuel only.
FUEL SYSTEM PRIMING
A certain amount of air becomes trappedin 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 systempriming.
The fuel transfer (lift) pump is self-priming: When the key is first turnedon (without cranking engine), the pump
operates for approximately 1 to 2 second and then shuts off (Note: When ambient temperatures are cold enough to
cause the intake air heaters to operate, the fuel lift pump will operate during the entire intake air pre-heat cycle).
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 onand 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 to OFF position, and leave it off for at least
5 seconds. 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.
PUMP - FUEL INJECTION
DESCRIPTION
A Robert Bosch high-pressure fuel injection pump is used. The pump is attached to the back of the timing gear
housing at the left /front side of the engine.
OPERATION
The fuel injection pump supplies high pressure to the fuel rail independent of engine speed. This high pressure is
then accumulated in the fuel rail. High pressure fuel is constantly supplied to the injectors 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 transfer (lift) pump, which is located in the fuel tank. Fuel is forced
through the fuel filter element 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 producepressures ranging from 551.5 kpa
(80 psi) to 1241 kpa (180) psi. Fuel then enters the fuel injection pump. Lowpressure fuel is then supplied 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 opening and closing the FCA based on a demanded fuel pressure. The FPS (Fuel
Pressure Sensor) on the fuel rail provides the actual fuel pressure. When the actuator is opened, the maximum
amount of fuel is being supplied to the fuel injection pump. Any fuel that does not enter the injection pump is
directed to the cascade overflow valve. The cascade 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 (4351-23206 psi) by three radial pumping
chambers. The pressurized fuel is then supplied to the fuel rail.
DIAGNOSIS AND TESTING
FUEL INJECTION PUMP TIMING
With the Bosch injection pump, there are no mechanical adjustments neededor necessary to accomplish fuel injec-
tion timing. All timing and fuel adjustments are electrically made by the engine mounted Engine Control Module
(ECM).
REMOVAL
CAUTION: Cleanliness cannot be overemphasized when handling or replacingdieselfuelsystemcompo-
nents. 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 possible 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. Capor cover any open part after
disassembly. Before assembly, examine each part for dirt, grease or othercontaminants and clean if nec-
essary. When installing new parts, lubricate them with clean engine oil orclean diesel fuel only.
LINES - FUEL
DESCRIPTION
Low-Pressure Lines Are:
the fuel supply line from fuel tank to fuel filter housing.
the fuel return line back to fuel tank.
the fuel drain (manifold) line at rear of cylinder head.
the fuel supply line from fuel filter to fuel injection pump.
the fuel injection pump return line.
High-Pressure Lines Are:
the fuel line from fuel injection pump to fuel rail.
the 6 fuel lines from fuel rail up to injector connector 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 the brace. The lines cannot contact each
other or other components. Do not attempt to weld high-pressure fuel linesor to repair lines that are dam-
aged. If lines are ever kinked or bent, they must be replaced. Use only the recommended lines when
replacement of high-pressure fuel line is necessary.
High-pressure fuel lines deliver fuel (under pressure) 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-pressure fuel pulses generated
during the injection process. All high-pressure fuel lines are of the samelength and inside diameter. Correct high-
pressure fuel line usage and installation is critical to smooth engine operation.
WARNING: 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.
DIAGNOSIS AND TESTING
HIGH-PRESSURE FUEL LINE LEAKS
High-pressure fuel line leaks can cause starting problems and poor engineperformance.
WARNING: Due to extreme fuel pressures of up to 160,000 kpa (23,206 psi), use extreme caution when
inspecting for high-pressure fuel leaks. Do not get your hand or a finger near a suspected leak. 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.
Start the engine. Move the cardboard over the suspected high-pressure fuel line leak, and check for fuel spray onto
the cardboard. If line is leaking, retorque line while engine is shutdown.Replace damaged, restricted or leaking
high-pressure fuel lines with the correct replacement line.
CAUTION: The high-pressure fuel lines must be clamped securely in place inthe brace. 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. Only use the recommended lines when replacement of high-pressure fuel line is neces-
sary.
PUMP - FUEL TRANSFER
DESCRIPTION
The fuel transfer pump (fuel lift pump) is part of the fuel pump module. The fuel pump module is located in the fuel
tank. The 12–volt electric pump is operated and controlled by the Engine Control Module (ECM). The ECM controls
a relay in the Intelligent Power Module(IPM) for transfer pump operation.
OPERATION
The purpose of the fuel transfer pump is to supply (transfer) a low-pressure fuel source:fromthe fuel tank,through
the fuel filter/water separator andtothe fuel injection pump. Here, the low-pressure is raised to a high-pressure by
the fuel injection pump for operation of the high-pressure fuel injectors. Check valves within the pump, control direc-
tion of fuel flow and prevent fuel bleed-back during engine shut down.
Maximum current flow to the pump is 5 amperes.
With the engine running, the pump has a 100 percent duty-cycle.
The transfer pump is self-priming: When the key is first turned on (withoutcranking engine), the pump will operate
for approximately 2 seconds and then shut off (Note: When ambient temperatures are cold enough to cause the
intake air heaters to operate, the fuel lift pump will operate during the entire intake air pre-heat cycle). The pump will
also operate for up to 25 seconds after the starter is engaged, and then disengaged and the engine is not running.
The pump shuts off immediately if the key is on and the engine stops running.
The fuel volume of the transfer pump will always provide more fuel than the fuel injection pump requires. Excess
fuel is returned from the injection pump through an overflow valve, and then back to the fuel tank.
REMOVAL
The fuel transfer pump (fuel lift pump) is a part of the fuel tank module. It is not serviced separately. Refer to Fuel
Tank Module Removal or Installation for procedures (Refer to 14 - FUEL SYSTEM/FUEL DELIVERY/FUEL TANK
MODULE - REMOVAL).
INSTALLATION
The fuel transfer pump (fuel lift pump) is a part of the fuel tank module. It is not serviced separately (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL TANK MODULE - INSTALLATION).