Removal And Installation Of The Hydraulic Electronic Unit Injectors{1290} Caterpillar

Engine: 3408E and 3412E In All Applications

Introduction

This Special Instruction gives detailed instructions on the disassembly and assembly of the 3408E and 3412E injectors. The entire instruction should be read and understood before you begin work on the engine.

Note: Contact your Caterpillar dealer to verify the current engine control software is installed for optimum injector life and engine performance.

Checklist For The Proper Installation And Removal Of The Injector

• All of the tools that are listed should be obtainable.

• The proper sequence must be followed for the removal of the injector. This includes the use of the 131-3921 Injector Puller .

• The carbon should be cleaned out of the injector sleeve. The clearance must be verified by using the 164-5924 Injector Sleeve Bore Gauge .

• The proper torque procedure for the injector jumper tube and assembly must be followed.

• Purge the air from the fuel lines. Check for fuel leaks and for combustion gas leakage.

Failure to follow these instructions can result in failure of the tip and severe engine damage.

Necessary Tools

• 131-3921 Injector Puller

Tools For Cleaning Carbon Deposits From The Injector Sleeve Bores

• 4C-5027 Tap Wrench

• 4C-6161 Tube Brush

• 4C-6774 Vacuum Gun Kit

• 8T-7765 Surface Reconditioning Pad

• 1U-5512 Cut & Polish Roll

• 9U-6102 Reamer

• 9U-6862 Tapered Brush

• 164-5924 Injector Sleeve Bore Gauge

Tools For Evacuating Fuel From The Cylinders

• 4C-4057 Tube

• 1U-5718 Vacuum Pump

• 1U-5814 Bottle Assembly

Optional Tool

• 164-5927 Tube Brush

Evacuating Fuel From The Fluid Manifold

1. Prior to removing the injector, evacuate as much fuel as possible from the manifold.

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Illustration 1	g00484352
(A) Top view. (B) Front view.

2. Remove the fuel line (1) that is routed from the T-connector on the front of the engine to the front of the manifold.

3. Place the loose end of the fuel line (1) into an appropriate container in order to collect the fuel.

4. Use an air gun with a rubber tip in order to evacuate the fuel with pressurized air.

   1. Place the rubber tip of the air gun in the fuel line opening of the manifold.

   2. Approximately 138 to 207 kPa (20 to 30 psi) of pressurized air should be enough to evacuate the fuel from both manifolds without damaging the injectors.

5. When the fuel in the system has been evacuated, reconnect the fuel line to the manifold.

6. Fuel and oil will still need to be removed from the cylinder after the injectors are removed.

Removal Of The Injector

Illustration 2	g00336078
This is a typical example of a 3408E Injector and a 3412E Injector. The tip has been broken by abuse or by incorrect installation.

Illustration 3	g00337536
(1) Bolts. (2) Adapter. (3) Socket head screws. (4) Bolt. (5) Injector jumper tube. (6) Injector. (7) Clamp. (8) O-ring seal. (9) Injector sleeve. (10) O-ring seal.

1. Close the shut off valve for the fuel supply.

2. Remove the valve cover assembly. Remove the bolts (1) from the injector jumper tube (5) .

3. Remove the injector jumper tube (5) .

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Illustration 4	g00337632
(4) Bolt. (7) Clamp. (11) O-ring seal. (12) Wiring harness.

4. Remove the clamp bolt (4) and the clamp (7) .

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Illustration 5	g00337672
(12) Wiring harness.

5. Remove the wiring harness (12) from the injector solenoid.

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NOTICE
The correct injector removal procedures and tooling specified in this Special Instruction MUST ALWAYS be used. Any leverage applied below the injector valve body can cause deformation of the poppet valve bore and possible failure. Do NOT pry on the injector.

6. Remove the injector by using one of the following methods:
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   Illustration 6	g00337715
   This is an example of a manual removal of the injector.

   1. When you are removing the injector by hand, grasp the injector and twist. The carbon that has built up on the seat should break loose. The injector can then be lifted out. If the seat cannot be broken loose by hand, the 131-3921 Injector Puller should be used.
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   Illustration 7	g00337717
   131-3921 Injector Puller . (13) Injector stud assembly. (14) Puller handle. (15) Washer. (16) Puller bridge assembly.

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   Illustration 8	g00337716
   This photo illustration shows the proper position of the injector puller.

   2. The following Steps should be followed when you remove the injector by using the 131-3921 Injector Puller :
      • Remove the socket head screws (3) .

      • Remove the adapter (2) .

      • Remove the O-ring Seal (11) .

      • Install the 131-3921 Injector Puller . Remove the injector.

7. Remove the O-ring Seal (8) and the O-ring Seal (10) from the injector (6) .

8. Repeat Step 2 through Step 7 for the remainder of the injectors.

Steps For Cleaning The Carbon Deposits

Illustration 9	g00337772
This is an example of a typical injector sleeve. (1) 120 degree angled surface of the injector sleeve. The lower O-ring seal contacts the injector sleeve in this area. (2) The injector tip fits in this bore in the injector sleeve.

Cleanliness is essential to the proper sealing of the injector. All carbon deposits should be removed from the injector sleeve and the bore (2). Carbon deposits should also be removed from the 120 degree angled surface (1) at the bottom of the injector sleeve.

Illustration 10	g00337773
This is an example of a typical injector. The entire lower portion of the injector should be clean. Extra attention should be paid to the lower O-ring seal groove (3) and the adjacent surface.

Cleaning The 120° Angled Surface Of The Injector Sleeve

The fine grade of the Scotch Brite material is preferred. Scotch Brite is available from the Tools And Shop Products Guide as the 1U-5512 Cut & Polish Roll and as the 8T-7765 Surface Reconditioning Pad .

The following procedure is the preferred method of cleaning the surface of the sleeve (1) :

1. Place a 38 mm (1.5 inch) square piece of Scotch Brite material on the end of a 9U-6862 Tapered Brush .

2. Twist the 9U-6862 Tapered Brush with the 4C-5027 Tap Wrench against the lower surface (1) of the sleeve bore.

Note: The carbon deposits should not be difficult to remove. The use of power tools is not necessary.

3. When the angled surface of the sleeve is thoroughly cleaned, the surface will be smooth and shiny. The entire sleeve bore should be cleaned so that any loose carbon particles will be removed.

Cleaning The Bore

Clean the bore (2) of the injector sleeve. If the injector sleeve is installed in the engine, use the 4C-6161 Tube Brush or the 164-5927 Wire Brush in order to clean the carbon deposits from the bore. If the injector sleeve has been removed from the engine, a 9U-6102 Reamer can be used in addition to the brush in order to remove the carbon deposits from the bore.

Note: The 164-5927 Tube Brush may be substituted for the 4C-6161 Tube Brush . The 164-5927 Tube Brush has a shortened handle that facilitates use in tight engine compartments.

Note: A 4C-6774 Vacuum Gun Kit is available for cleaning the loose material from the sleeve bore.

The following Steps should be used in order to check the clearance in the sleeve:

1. After the injector sleeve has been cleaned with the 9U-6102 Reamer or the 4C-6161 Tube Brush , use the 164-5924 Injector Sleeve Bore Gauge to determine that an adequate amount of carbon has been removed.

2. The gauge should be inserted into the injector sleeve until the cross pin contacts the top of the sleeve. This ensures that the gauge will extend completely through the hole. The gauge should not contact the piston. If the gauge can be easily seated, enough of the carbon has been cleaned out.

3. If the gauge cannot pass through the sleeve bore and the seat correctly, additional cleaning is necessary.

4. If additional cleaning has been tried and the gauge will not pass through the injector sleeve, the sleeve should be replaced. Consult the Disassembly And Assembly Manual for the proper procedures on the replacement of the injector sleeve.

Evacuation Of Fuel And Oil From The Cylinder

Evacuate as much fuel and oil as possible from the cylinder before installation of the injector. Use the 1U-5718 Vacuum Pump , 1U-5814 Bottle Assembly , and the 4C-4057 Tube to evacuate the fluid. Several evacuations may be necessary. More than one bottle of fluid may be in the cylinder. Crank the engine with the disabled injectors after the evacuation of the cylinder. Refer to the ""Cranking Without Injecting" " section for more information.

Installation Of The Injector

Illustration 11	g00484346
(1) O-ring seal. (2) O-ring seal. (3) Tapered seat. (4) Injector tip.

1. Clean the carbon from the following areas of the injector:
   • The tapered seat (3) on the injector

   • The tapered seat in the injector sleeve

   Note: If you choose to clean the angled seat on the injector with a wire brush, the wire brush should not contact the tip (4). A wire brush may damage the fuel injection nozzle holes.

2. Install a new O-ring seal (1) and a new O-ring seal (2). Lubricate the O-ring seals and the injector bore sparingly with clean engine oil.

3. Install the injector in the original location in the injector sleeve.

4. Place a 161-3568 Grommet on the top of each injector prior to installing the wiring harness.

Unit Injector Wiring Harness

Note: The entire instruction should be read and understood before you begin work on the engine. Failure to follow these instructions can result in serious engine damage.

Illustration 12	g00628332
(1) White connector. (2) "F" mark. (3) Sleeve. (4) "R" mark. (5) Black connector.

Illustration 13	g00635542
Detail A

Identification Of The Connectors And Cylinder Number Location

Illustration 14	g00628376
(A) Connector identification for rear cylinder. (B) Connector identification for front cylinder. (C) Flywheel housing. (D) Cylinder number location. (E) Rear of engine.

Note: The front of the engine is opposite the flywheel housing end. The left side and the right side of the engine are viewed from the flywheel housing. The front of the machine may or may not be the front of the engine and should not be used as a reference for determining the orientation of the engine.

Installation Of The Wiring Harness Assembly

Illustration 15	g00628445
(1) White connector. (2) "F" mark. (3) Sleeve. (4) "R" mark. (5) Black connector. (6) Nuts. (7) Flywheel housing. (8) Centerline of the crankshaft.

Each harness assembly has a white connector marked "F" (front) and a black connector marked "R" (rear). One harness assembly is used for two cylinders under each valve cover. The white connector must be installed on the injector toward the front of the engine. The black connector must be installed on the injector toward the rear of the engine.

The wires for the white connector are enclosed within a sleeve. The cylinder numbers 1, 2, 5, 6, 9, and 10 are printed on the sleeve. The wires for the black connector are not enclosed within a sleeve.

One harness assembly is used for two cylinders under each valve cover.

1. The white connector (1) is marked "F" (front). Assemble the white connector (1) to the injector on the front cylinder. The front cylinders are 1, 5, and 9 on the left side of the engine and 2, 6, and 10 on the right side of the engine.

2. Torque the nuts (6) to the following torque.

   Torque for nuts ... 1.70 ± 0.25 N·m (15 ± 2 lb in)

3. The black connector (5) is marked "R" (rear). Assemble the black connector (5) to the injector on the rear cylinder. The rear cylinders are 3, 7, and 11 on the left side of the engine and 4, 8, and 12 on the right side of the engine.

4. Torque the nuts (6) to the following torque.

   Torque for nuts ... 1.70 ± 0.25 N·m (15 ± 2 lb in)

   Note: Cylinders 9, 10, 11, and 12 are not applicable to a 3408E engine.

   Note: A film is supplied with the wiring harness. The film illustrates the correct combination of the harness connector and of the right cylinder number injector. Install the film on top of the rear left or on top of the rear right valve cover. The film should be legible from the side of the engine. There should be one film on each side of the engine. If a film is already installed on the valve cover, disregard the film that is supplied with the harness.

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Illustration 16	g00628694
(9) Fuel injector clamp. (10) Bolt. (11) O-ring seal.

5. Place the clamp (9) in the proper position. Temporarily place the jumper tube in position in order to ensure alignment of the bolt holes. Adjust the orientation of the injector until the alignment is satisfactory. Torque the bolt (10) to the following torque. Remove the jumper tube.

   Torque for bolt ... 47 ± 9 N·m (35 ± 7 lb ft)

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Illustration 17	g00628691
(12) O-ring seals in the injector jumper tube. (13) O-ring seals in the base of the rocker arm.

6. Replace the used O-ring seal (11), and the O-ring seals (12) and (13) in the jumper tube and in the rocker arm.

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Illustration 18	g00628693
(14) Jumper tube. (15) Bolts. (16) Adapter. (17) Socket head screws.

7. Place the jumper tube (14) and the adapter (16) into position.

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NOTICE
If the adapter was previously installed on the injector, loosen the socket head screws. Failure to loosen the socket head screws before continuing with Step 8 can result in injector failure.

8. Install the socket head screws (17) and the four bolts (15) finger tight.

Note: The mating surfaces should be brought into complete contact and into alignment before the final torque procedure is started.

Torque Procedure

Illustration 19	g00338156
(1) Socket head screws.

Illustration 20	g00338157
(2) Two horizontal bolts. (3) Two vertical bolts.

1. Tighten the socket head screws (1), the two horizontal bolts (2), and the two vertical bolts (3) finger tight.

2. Tighten the socket head screws (1) to an initial torque of 1 ± .2 N·m (9 ± 2 lb in).

3. Tighten the horizontal bolts (2) to an initial torque of 5 ± 3 N·m (44 ± 27 lb in).

4. Tighten the vertical bolts (3) to an initial torque of 5 ± 3 N·m (44 ± 27 lb in).

5. Tighten the socket head screws (1) to a final torque of 12 ± 3 N·m (9 ± 2 lb ft).

6. Tighten the horizontal bolts (2) to a final torque of 47 ± 9 N·m (35 ± 7 lb ft).

7. Tighten the vertical bolts (3) to a final torque of 47 ± 9 N·m (35 ± 7 lb ft).

8. Repeat Step 1 through Step 7 for the remainder of the injectors.

9. Check the fuel system for leaks by cranking the engine with the disabled injection. Then check the hydraulic pressure. Compare the pressure to the desired pressure.

Cranking Without Injecting

Cranking the engine with the disabled injection may be performed by one of the following methods:

• Disconnect the injector harness of the cylinders which have been reinstalled. Allow the engine to idle. Visually inspect the injector's components for high pressure oil leaks.

• Activate the system "Crank Without Inject" if the option is available. On Track-Type Tractors, a "Crank Without Inject" plug can be assembled in the engine harness. On Off-Highway Trucks, the "Ground Level Shutdown" can be activated if the option is available.

• When you are using the CAT ET or the ECAP, the injection may be disabled by interactive diagnostics. The engine can be left idling while the injectors' components on the affected cylinders are visually examined for high pressure oil leaks.

Checking For Fuel Leaks, Air In The System, And Combustion Gas Leakage

Oil under high pressure may leak from the jumper tube connections. Oil may also leak from the fuel injector body's exhaust port. Fuel could leak from the upper O-ring seal on the injector.

If air has entered the fuel supply system, multiple injectors on one bank may malfunction. If the injectors were not properly tightened, combustion gas and air could enter the injector through the lower O-ring seal. If the lower O-ring seal should fail, replace the O-ring seal. Perform the torque sequence again.

Note: Air in the system may be detected by gently touching the flexible return line. Check for extreme pulsations and pressure spikes through each line. As an alternative, install a sight glass in each return line. Run the engine. Check for air bubbles in the sight glass.

Combustion gas leakage can occur from the base of the injector. Combustion gas leakage will usually affect the injector that has the leak first. The leakage will then affect the injectors that are downstream of the leak.