Removal And Installation Instructions For The HEUI Injector{1290} Caterpillar

Engines:

3126B (S/N: 3GS1-UP; 7JZ1-UP; 8SZ1-UP; 8YL1-UP; 1AJ1-UP; 6PZ1-UP; BKD1-UP; 7AS1-UP)

3126E (S/N: 9SZ1-UP; CKM1-UP; CRP1-UP)

Introduction

This Special Instruction provides the removal procedure and the installation procedure for the HEUI Injector.

The injector is not serviceable. The warranty and/or the core credit for remanufacturing may be reduced for the following reasons:

• Disassembling or tampering with the injector

• Not returning the injector in the original protective packaging

• Damaging the injector during removal or installation

Note: An injector with possible damage to the tip must be returned in the original package. The damaged injector must be clearly identified as having possible tip damage.

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

Tools For Evacuating Fuel From The Cylinders

• 4C-4057 Tube

• 1U-5718 Vacuum Pump

• 1U-5814 Bottle Assembly

Removal Of The Injector

Illustration 1	g00293685
(1) 128-6601 Solenoid Assembly (2) Harness Connector (3) Clamp (4) O-Ring Seals (5) 9Y-9025 Sleeve (6) Angled Seat (7) 137-5621 Tip Assembly

1. Remove the valve cover assembly.

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Illustration 2	g00777907
(8) Oil Drain Plug

2. Remove oil drain plugs (8) at each end of the cylinder head.

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Illustration 3	g00778847
(2) Wiring Harness Connection (3) Clamp (9) Injection Actuation Pressure Sensor (10) Shoulder Bolt (11) Socket Head Bolt

3. Remove the Injection Actuation Pressure Sensor (9) .

4. Allow the engine oil to drain from the ports in the cylinder head before the injector is removed.

5. Remove the harness connector (2) away from the injector solenoids.

6. Remove the Shoulder Bolt (10) and the Socket Head Bolt (11) from the clamp (3) .

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Illustration 4	g00294212

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Illustration 5	g00778851
(12) Do not pry here. (13) Tool (D) should be placed at this location in order to gently remove the injector.

7. Place Tool (D) under the clamp (13) on the flywheel side of the injector.

8. Use Tool (D) to remove the injector.

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Illustration 6	g00294208
(4) O-Ring Seals

9. Remove the O-Ring seals (4) from the injector.

10. Repeat Step 5 through Step 9 for the remainder of the injectors.

Steps For Cleaning The Carbon Deposits

Illustration 7	g00778868
(14) Metal Seal

Cleanliness is very important in the area around the sleeve and the sleeve bore when you are reinstalling the injector. This injector has a metal seal between the bottom of the injector's case and a seat in the cylinder head. Unlike the former designs which were seated against a brass sleeve, this injector seats in the cylinder head. Clean the carbon from the seat area that is inside of the cylinder head. Also clean the carbon from the end of the injector if the injector should be reinstalled.

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 Hand Pad .

If the sleeve of the injector has been removed from the engine, use a 9U-6102 Reamer to remove carbon deposits from the angled surface.

Note: Do not use the 9U-6102 Reamer in order to remove metal from the sleeve. Use the 9U-6102 Reamer in order to remove carbon only.

If the sleeve of the injector is installed in the engine, use the 4C-6161 Tube Brush to clean the carbon deposits from the inside of the sleeve.

If you choose to clean the angled seat on the injector with a wire brush, the wire brush should not contact the tip of the injector. Failure of the tip and major engine damage may result.

Note: Using power tools in order to rotate the material should not be necessary. The carbon in the sleeve is more removable than the carbon at locations that are exposed to higher temperatures.

The following procedure is the preferred method of cleaning the sleeve bore.

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 of the sleeve bore.

3. The surface should be cleaned until the surface is smooth and shiny. The entire sleeve bore should be cleaned in order to remove any loose carbon particles.

Note: A 4C-6774 Vacuum Gun Kit is available in order to clean the loose material from the sleeve bore.

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 fuel. Several evacuations may be necessary.

Installation Of The Injector

1. Install the oil drain plugs (8) and the Injection Actuation Pressure Sensor (9) .

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Illustration 8	g00778880
This is an illustration of the 154-8016 Fuel Injector Seals . (14) Metal Seal (15) 133-3715 Backup Ring (16) 150-4105 Backup Ring (17) 9X-7557 O-Ring Seal (18) 148-2903 O-Ring Seal (19) 149-5240 Backup Ring (20) 109-3207 O-Ring Seal

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Illustration 9	g00638512
(A) 149-2955 Seal Protector

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Illustration 10	g00638506
(B) 149-2956 Seal Installer

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NOTICE
The correct procedures and tooling specifications must always be used. Failure to follow any of the procedures may result in damage, malfunction, or possible engine failure.

Note: Install the upper seal pack first. Then install the middle seal pack. Finally, install the bottom O-Ring Seal.

2. Both the 149-2955 Seal Protector (A) and the 149-2956 Seal Installer (B) should be used when you are installing the upper high pressure seals.

   Note: New seals should be installed after each removal of the injector from the engine.

3. Lubricate the O-Ring seals and the sleeve bore of the injector sparingly with clean engine oil.

Note: Proper installation of the injector is very important. Damage to the upper high pressure seals can cause excessive oil leakage under the valve cover. This may cause the engine not to start due to a low actuation pressure. Damage to the lower high pressure seals may allow high pressure oil to leak into the fuel supply passage. This will result in excessive oil consumption.

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Illustration 11	g00621566
(X) 8T-2396 Bolts . (Y) 159-0288 Deflector .

Note: Some of these engines were built without the 159-0288 Deflector . During the installation of the unit injectors, the deflectors should be installed. Six 159-0288 Deflectors and six 8T-2396 Bolts are required for each engine. These new deflectors and bolts replace the former 6V-8653 Bolts .

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Illustration 12	g00294210

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Illustration 13	g00312124
(C) 152-1057 Fuel Injector Installer

4. Carefully install the injector into the injector bore. If access permits you to seat the injector, push the injector straight down on top of the injector's solenoid by hand until the injector is firmly seated in the injector bore. Pushing hard enough to compress the injector's seals may be difficult. If the injector can not be seated by hand, use a 152-1057 Fuel Injector Installer (C).

   Note: Do NOT pry on the top of the injector with another tool. Do NOT strike the injector with a hammer. Damage to the injector will result. Damage to the injector that is due to improper installation is not a warrantable failure.

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Illustration 14	g00778888
(2) Wiring Harness Connection (3) Clamp (10) Shoulder Bolt (11) Socket Head Bolt

Note: Do not use the shoulder bolt and the socket head bolt in order to seat the injector. If a side load is placed on the bolts, the bolts may fail.

5. After the injector is seated, position the clamp (2) and tighten the Shoulder Bolt (10) to a torque of 6 N·m (50 lb in). Then tighten the Socket Head Bolt (11) to a torque of 12 N·m (9 lb ft).

6. Insert the harness connectors (2) back into the injectors' solenoids. Ensure that the clips are snapped back into the proper position.

7. Check the system for leaks by using the following procedure.

Cranking Without Injecting

1. Visually inspect the components of the injector for oil leaks around the outside diameter.

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Illustration 15	g00778891

2. Disconnect the injector wiring harness with the 12-pin connector (20). The harness is located between the hydraulic pump and the cylinder head. Disconnect the Injection Actuation Pressure Sensor's connector. This will cause the oil pressure to raise to about 2500 psi.

3. Crank the engine in order to allow the actuation pressure to rise. Cranking the engine also purges the air from the system.

4. Visually check for oil leaks in the area that is between the outside diameter of the injector and the cylinder block.

   Note: A small amount of seepage from the injector's vent hole during cranking is normal. A large steady flow from one injector that is greater than the flow from the other injectors may indicate a problem with that injector.

5. If no leaks are found, connect the injector wiring harness (20) and the Injection Actuation Pressure Sensor.

6. Start the engine.

7. Check for oil leaks while the engine is running at idle.

8. If no leaks are found, install the ET or other electronic service.

9. Test the actuation pressure. Increase the actuation pressure to the maximum pressure (approximately 3300 psi).

10. If no leaks are found, check the crankcase oil level. Supply the proper amount of oil to the crankcase.

11. Install the valve cover assembly.

12. For additional information regarding the operation of the HEUI Fuel System, refer to the Service Manual, RENR1360. Additional information is also available on CD-ROM, RENR1390.