3126E On-highway Engine Caterpillar

Installation Procedure

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Illustration 1	g00865930

1. Install oil drain plugs (8) .

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Illustration 2	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 3	g00638512
(A) 149-2955 Seal Protector

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Illustration 4	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 5	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 6	g00865981

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Illustration 7	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 8	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.

Note: Install new bolts (10) and (11) .

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.

Check the Fuel System for Leaks

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

2. Disconnect the injector wiring harness with the 12-pin connector. The harness is located between the hydraulic pump and the cylinder head. Disconnect the Injection Actuation Pressure Sensor's connector. This connector is located on the top of the unit injector hydraulic pump. 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.

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 tools and clear all codes.

End By: Install the valve mechanism cover. Refer to Disassembly and Assembly, "Valve Mechanism Cover - Remove and Install".