Reuse Guideline for the Flexible Exhaust Pipe Group on Tier 4 Engines {1061} Caterpillar

Introduction

This Special Instruction will address the following applications for the lines group - flex pipe: the installation, the handling and the reusability. The lines group - flex pipe is defined as the connection between the turbocharger diffuser outlet and the Clean Emissions Module (CEM) inlet.

Available Replacement Bellows Assemblies

Tier 4 Interim and Tier 4 Final Commercial Engines

Tier 4 Final Commercial Engine Applications

Tier 4 Interim Machine Engines

Tier 4 Final Machine Engines

Removal of the Lines Group

Removal Procedure

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The ends of the bellows are very sharp. Injury could occur if the bellows are not handled properly. Handle the bellows by the convolutions.

The alignment of the bellows is important. Improper lateral alignment is two sealing surfaces that do not align with each other. The proper lateral adjustment is shown in Illustration 1.

Proper alignment means that initial alignment of all components that are held together by the components referenced in Illustration 1 are maintained.

Note: Do not force the bellows into the position.

Note: Failure to reinstall the bellows into the as removed alignment will result in a failure of the part and a needed replacement.

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Illustration 1	g02211913
(1) Alignment marks (2) Ball clamp (3) Tube (4) Slip joint clamp (5) Bellows (6) Ball clamp

1. Draw alignment marks that will cover both the lines group and the associated clamps. Refer to Illustration 1.
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   Illustration 2	g02239794
   Bellows with protective covering installed

2. Wrap the bellows with a protective cover to avoid possible damage to the bellows during the removal and installation.

3. Loosen clamp assemblies (2), and (6).

4. Remove the lines group.

   Note: Removal of the entire line group as a whole is ideal. However, in some applications the assembly must be disassembled further in order for the assembly to be removed.

   Note: Care should be taken when handling the lines group. The slightest bump or drop can result in a misalignment of the bellows and a possible need for replacement.

5. Discard clamp assemblies (2) and (6). The clamp assemblies are a one time use part.

   Note: Steps 6 through 7 are only necessary if clamp (4) was loosened to remove the entire lines group.

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   Illustration 3	g02231056
   (7) Weld

6. Remove clamp (4) from bellows (5) by removing weld (7). Use a grinding device to remove the spot weld.

   Note: Use care not to remove excessive amounts of material and grind on the bellows.

   Note: Do not use a vice to secure the lines group. The bellows cannot be damaged in any way during this procedure.

   Note: Use the proper personal protective equipment when removing clamp (4) from the bellows assembly.

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   Illustration 4	g02231059
   Remove the weld from the bellows assembly with a grinding device

7. Inspect the clamping surface on the outside of the bellows. Deburr the surface if necessary.

   Note: If the bellows assembly is damaged during the removal of clamp (4), replace the bellows assembly.

Installation

Note: Step 1 is only necessary if clamp (4) was loosened to remove the entire lines group.

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Illustration 5	g02231073

1. Install new clamp (4) with the tightening assembly centered between reliefs (A). Do not torque the clamp until Step 12

   Note: The end of the clamp must be flush with the end of the bellows assembly.

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   Illustration 6	g02211937

2. Distance (X) is 40 mm (1.6 inch). Place Mark (B) onto tube (3) at Distance (X) from the end of tube (3).

3. Insert tube (3) into the bellows. The tube should be inserted as far as possible without using force. This action will minimize the overall length of the lines group and will help with installation.
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   Illustration 7	g02211913
   Alignment wrap is not shown for photographic purposes.

4. Prior to installation, position both ball clamp assemblies (2) and (6) onto the lines group.

5. Position the lines group between the Clean Emissions Module and the turbocharger adapter. Adjust the length of tube (3) in the slip joint at clamp assembly (4) in order to position the lines group.

   Note: Do not force any of the components into the position.

   Note: Make sure that you loosely fit all of the parts before the final torquing is started.

   Note: Failure to reinstall the bellows into the original alignment will result in a failure of the part and a needed replacement.

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   Illustration 8	g02211953
   The photo is a cutaway view of the ball clamp assembly.

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   Illustration 9	g02211955
   The photo is a cutaway view of the ball clamp assembly.

6. Verify that the cup of the ball joint (E) does not touch the radius of the ball (D). Position ball clamp (2) and loosely tighten ball clamp (2).

   Note: The ball clamp that is opposite the bellows must always be tightened first. Clamp (2) which can be located at the turbocharger diffuser outlet or the CEM inlet must be tightened first. Refer to Illustration 10 and Illustration 11 for example of the possible placement of clamp (2).

7. Verify that the ball clamp is centered. Measurement (Y) and measurement (Z) must be within 2 mm (0.07874 inch) of each other. Refer to Illustration 9.
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   Illustration 10	g02239874
   Example of configuration with the bellows located near the turbocharger outlet

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   Illustration 11	g02239877
   Example of configuration with the bellows located near the CEM inlet

8. Repeat Step 6 and 7 for ball clamp (6).

9. Verify that Mark (B) is not visible at the slip joint that is positioned near clamp assembly (4).

   Note: Use hand tools to torque clamps on Steps 10 through 12. Do not use power tools in order to torque clamp assemblies (2), (4), and (6).

   Note: The ball clamp that is opposite the bellows must always be tightened first. In Illustration 10 the ball clamp that must be tightened first is located at the CEM inlet. In Illustration 11 the ball clamp that must be tightened first is located at the turbocharger diffuser outlet.

10. Torque ball clamp (2) to a torque of 35 ± 2 N·m (26 ± 1 lb ft).

11. Torque ball clamp (6) to a torque of 35 ± 2 N·m (26 ± 1 lb ft).

12. Torque clamp assembly (4) to a torque of 55 ± 8 N·m (41 ± 6 lb ft).

13. Remove the protective cover that was installed in Step 2 of the removal section.

Examples of Possible Misalignment and Results

Illustration 12	g01023261
Example of lateral misalignment

Lateral misalignment is shown in Illustration 12. Lateral misalignment on the exhaust bellows can lead to contact between liner and convolutions. The misalignment can cause premature failure.

Lateral misalignment is identified by visually inspecting the convolutions on the bellows. The visual inspection will help ensure an even amount of spacing between each of the convolutions.

Illustration 13	g01016673
Example of premature failure due to lateral misalignment

Improper alignment during installation can lead to premature failure of the bellows. An Example of premature failure is shown in Illustration 13.

Handling

Bellows should be handled by the convolutions. The convolutions are the ribbed portion of the bellows. The ends of the bellows could be sharp and the ends should be handled carefully. The bellows can be damaged if the bellows are dropped.

Reusability

Note: If there are any indications of separation of the layers or difficulty with the installation, discard the bellows. Failure to replace the bellows could result in the following problems: improper seating, subsequent air leakage and Exhaust leakage.

The bellows consist of multiple layers of material that are pressed together.

Illustration 14	g01016669
Example of damage to the convolutions

Inspect the bellows for damage. The part should be discarded if damage to the convolutions is present. Illustration 14 shows that damage to the convolutions.

Illustration 15	g02240434
Example of a bad edge

If damage has occurred to the edges of the bellow, the bellows must be replaced.