Tube Assemblies for the Low-Pressure Fuel System on Certain C6.6 Machine Engines{1274, 1307, 1408} Caterpillar

Introduction

There have been isolated instances of issues with 353-3571 Filter Tube that are installed on certain C6.6 machine engines.

The fuel system can have different types of tube assemblies installed between the secondary fuel filter assembly and the fuel injection pump. Refer to Special Instruction, REHS3754, "New Tube Assembly for the Low-Pressure Fuel System on Certain C6.6 Machine Engines" for further information.

Harness Assembly at Relief Valve (Fuel) and Fuel Manifold (Rail)

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Illustration 1	g03721132
Typical example

1. Inspect the harness assembly (3) to determine if there is sufficient clearance between the harness assembly and relief valve (fuel) (1) and fuel injection lines (2) at Position (X) and Position (Y). The minimum clearance should be 5 mm (0.197 inch).

2. If there is less than 5 mm (0.197 inch) clearance, cut cable strap from the harness assembly connected to the electronic unit injectors on number three and number four cylinders.

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Illustration 2	g03721137
Typical example

3. Adjust harness assembly (3) to provide sufficient clearance around fuel injection line (2) and connection.

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Illustration 3	g03721141
Typical example

4. Install two new cable straps (4) that are interlinked to harness assembly (3). Harness assembly (3) should be secured to relief valve (fuel) (1). Refer to illustration 3.

   Note: Ensure that 217-9039 Cable Strap or 3S-2093 Cable Strap is used.

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Illustration 4	g03721142
Typical example

5. Ensure that harness assembly (3) is not strained. The harness should be free of corrosion, abrasions, and pinch points.

Harness Assembly at Engine Oil Cooler

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Illustration 5	g03721143
Typical example

1. Inspect the harness assembly to determine if there is sufficient clearance between the harness assembly (1) and tube assemblies (2) at Position (X) and Position (Y). The minimum clearance should be 5 mm (0.197 inch).

2. Some applications may have a canister for the crankcase breather installed in this location. The canister for the crankcase breather would have to remove to improve access. Refer to Disassembly and Assembly, "Crankcase Breather - Remove - Filtered Breather" for more information.

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Illustration 6	g03721144
Typical example

3. Cut cable strap (3) from harness assembly (1). Adjust the position of harness assembly (1) to improve the clearance between harness assembly (1) and fuel injection line (4). Install new cable strap (3) to harness assembly (2) .

   Note: Ensure that 217-9039 Cable Strap or 3S-2093 Cable Strap is used.

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Illustration 7	g03721182
Typical example

4. Ensure that there is sufficient clearance between harness assembly (1) and tube assembly (2). Install new cable strap (3) to harness assembly (1). Ensure that there is a sufficient loop in the harness assembly to prevent the cable strap becoming loose. Refer to illustration 7. Ensure that harness assembly (1) is not strained. The harness should be free of corrosion, abrasions, and pinch points.

Hose for the Filtered Crankcase Breather

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Illustration 8	g03721265
Typical example

1. Inspect the tube assemblies (2) that are located behind the hose (1) for the crankcase breather at Position (X) and Position (Y). If the tube assemblies come into contact with the hose for the crankcase breather, then damage can occur.

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Illustration 9	g03721277
Typical example of 317-7147 Clip

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Illustration 10	g03721279
Typical example

2. Obtain 317-7147 Clip . Remove clip (3) from assembly. Retain clip. Discard Male section (4) with cable strap.

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Illustration 11	g03721557
Typical example

3. Obtain 395-1663 Tie . Install clip (3) to tie (5) .

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Illustration 12	g03721560
Typical example

4. Install clip (3) to tube assembly (2). Install tie (5) to hose (1) for the crankcase breather.

Harness Assembly around Tube Assemblies

The engine has two types of installation for the harness assembly and the tube assemblies. Select the appropriate type of installation for the engine.

Type 1 Lower Tube Assembly Installation

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Illustration 13	g03721747
Typical example

1. Inspect harness assembly (2) to determine the current position of the harness assembly. If current position of the harness assembly (2) is over tube assemblies (1), the position of the harness assembly needs to be adjusted. Refer to illustration 13. Proceed to step 2

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Illustration 14	g03721755
Typical example

2. Disconnect harness assembly (2) from connections. reroute harness assembly under tube assemblies (1). Refer to illustration 14. Connect harness assembly (2) to connection.

3. Install 3S-2093 Cable Strap (3) to harness assembly (2). Ensure that there is sufficient clearance between harness assembly (2) and tube assemblies (1) .

Type 2 Upper Tube Assembly Installation

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Illustration 15	g03721832
Typical example

1. Inspect tube assemblies (2) to determine if there is sufficient clearance between the tube assemblies (2) and harness assembly (1) at Position (X). If there is insufficient clearance between the tube assemblies and harness assembly, the harness assembly needs to be adjusted. Proceed to step 2

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Illustration 16	g03721842
Typical example

2. Cut cable strap (3) on ladder clip (4). Adjust harness assembly (1). Harness assembly (1) should be positioned vertically down with sufficient clearance between the tube assemblies and harness assembly. Refer to illustration 16. Install new cable strap (3) to ladder clip (4) .

   Note: Ensure that 217-9039 Cable Strap or 3S-2093 Cable Strap is used.

Hose for the Unfiltered Crankcase Breather

1. Inspect the tube assemblies that are located behind the hose for the crankcase breather. If the tube assemblies come into contact with the hose for the crankcase breather, then damage can occur.

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Illustration 17	g03721584
Typical example

2. If necessary, install 334-4155 Clip (3) to tube assemblies (2). Refer to illustration 17. Ensure that there is sufficient clearance between hose for the crankcase breather (1) and tube assemblies (2) .

Harness Assembly at Top of Mounting Bracket for Electronic Control Module (ECM)

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Illustration 18	g03721607
Typical example

1. Inspect the harness assembly to determine if there is sufficient clearance between the harness assembly (2) and tube assembly (1) at Position (X) .

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Illustration 19	g03721277
Typical example of 317-7147 Clip

2. Install 317-7147 Clip to tube assembly and harness assembly in order to ensure sufficient clearance.

Tube Assembly above Electric Fuel Priming Pump

Illustration 20	g03721610
Typical example of an installation with sufficient clearance

Illustration 21	g03721613
Typical example of an installation with insufficient clearance

1. Inspect tube assembly (1) to determine if there is sufficient clearance between the tube assembly and electric fuel priming pump base (2) at Position (X). Refer to illustration 20 and illustration 21. If the installation has sufficient clearance between the tube assembly and electric fuel priming pump base, no further action should be taken. If the installation has insufficient clearance between the tube assembly and electric fuel priming pump base, proceed to step 2.

   Note: If there is insufficient clearance between tube assembly and fuel filter bracket, tube assembly may need to be removed from the engine. If tube assembly needs to be removed from the engine, electric fuel priming pump base will have to be removed to improve access. Refer to ""Tube Assembly around Fuel Filter Bracket" " for more information.

2. Use a suitable lifting device to support electric fuel priming pump base (2) .

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Illustration 22	g03721616
Typical example

3. Remove existing bolt (3) and bolts (4) .

4. Position electric fuel priming pump base (2) away from the bracket. Inspect tube assembly (1) for wear or for damage, if the tube assembly is worn or damaged, replace tube assembly (1) .

5. Position a spacer between electric fuel priming pump base (2) and the bracket. Install new 8T-6870 Bolt (3) to electric fuel priming pump base (2). Tighten bolt finger tight.

   Note: Use 090-9434 Spacer or 226-1388 Spacer .

6. Position two spacers between electric fuel priming pump base (2) and the bracket. Install new 9X-6000 Bolts (4) to electric fuel priming pump base (2). Tighten bolts finger tight.

7. Ensure that tube assembly (1) has sufficient clearance between the tube assembly and electric fuel priming pump base (2). Tighten bolt (3) and bolts (4) to a torque of 44 N·m (32 lb ft).

Harness Assembly at Fuel Injection Pump

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Illustration 23	g03721619
Typical example

1. Inspect the harness assembly (1) to determine if there is sufficient clearance between the harness assembly tube assembly (2) at Position (X) .

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Illustration 24	g03721621
Typical example

2. Adjust harness assembly (1) to provide sufficient clearance around tube assembly (2). Install new cable strap (3) to harness assembly (1) .

   Note: Ensure that 217-9039 Cable Strap or 3S-2093 Cable Strap is used.

3. Ensure that harness assembly (1) is not strained. The harness should be free of corrosion, abrasions, and pinch points.

Tube Assembly around Fuel Filter Bracket

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Illustration 25	g03721896
Typical example

1. Inspect tube assembly (1) to determine if there is sufficient clearance between the tube assembly (1) and the fuel filter bracket (2) at Position (X). If there is insufficient clearance between the tube assembly and the fuel filter bracket, proceed to step 2.

2. If necessary, remove electric fuel priming pump base in order to improve access.

3. Remove complete tube assembly (1) from the engine.

4. Use Tooling (A) in order to plug the plastic tube assembly. Use Tooling (A) in order to cap the connections for plastic tube assembly.

5. Obtain 5I-4200 Guard (3) .

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Illustration 26	g03722028
Typical example

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Illustration 27	g03722031
Typical example

6. Wrap the guard (3) in a counter clockwise motion for a right hand side wrap around tube assembly (1). Refer to illustration 26. Make sure the gap between the each spiral is not too big. If the gap is too big, spin the wrap clockwise will allow you to loosen the guard and reduce the gaps. Refer to illustration 27.

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Illustration 28	g03722059
Typical example (Y) 319-7347 Fuel Line

7. Continue to wrap the guard (3) around tube assembly (1) until the desired section of around tube assembly (1) is covered. Cut excess guard with suitable wire cutters. A length of 182 mm (7.164 inch) guard (3) requires installation. Refer to illustration 28 for an example of a finished installation.

8. Remove plugs from tube assembly (1). Remove caps from connections.

9. Install complete tube assembly (1) to the engine.

10. If necessary, install electric fuel priming pump base.

Harness Assembly behind Bracket for Secondary Fuel Filter Base

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Illustration 29	g03721622
Typical example

1. Inspect the harness assembly (1) to determine if there is sufficient clearance between the harness assembly tube assembly (2) at Position (X) .

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Illustration 30	g03721623
Typical example

2. Cut existing cable strap (3) from harness assembly (1) .

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Illustration 31	g03721624
Typical example

3. Adjust harness assembly (1) to provide sufficient clearance around tube assembly (2). Install new cable strap (3) to harness assembly (1) .

   Note: Ensure that 217-9039 Cable Strap or 3S-2093 Cable Strap is used.

4. Ensure that harness assembly (1) is not strained. The harness should be free of corrosion, abrasions, and pinch points.