1993/08/02 Caterpillar

New Tube Assemblies Used In Air Lines Group Allow Greater Movement{1058}

Usage:

3412 (81Z) Generator Sets and Marine Auxiliary Engines;
3412 (38S) Industrial Engines

Description of Change: New tube assemblies are used in air lines group. The new tubes include bellows to allow greater movement for expansion and contraction of the tubes.

Adaptable To: The new 6I2854 and 6I2855 Tube Assemblies with integral bellows directly replace the former two 7E3901 Tubes and the 7E3907 and 7E3906 Tube Assemblies in the 4W7649 Air Lines Group on certain 3412 Engines. The new components are used on 3412 Generator Sets and Marine Auxillary Engines effective with 81Z14231 and on 3412 Industrial Engines effective with 38S16423. These engine arrangements have twin turbos.

NOTE: Caterpillar recommends using new 8N0879 Clamps when installing the new tube assemblies. Tighten clamps to a torque of 7.5 ± 1.0 N·m (67 ± 9 lb in). Lightly tap around the clamp with a hammer. Then tighten the clamp to a torque of 7.5 ± 1.0 N·m (67 ± 9 lb in).

Illustration 1. Location of components for 4W7649 Air Lines Group.

NOTE: It is not necessary to replace items 3-6 when installing the new Tube Assemblies.

Caterpillar Information System:

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