Usage:
NOTE: The information supplied in this service letter may not be valid after the termination date of this program. Do not perform the work outlined in this Service Letter after the termination date without first contacting your Caterpillar product analyst.
NOTE: This Program can be administered either before or after a failure. In either case the decision whether to apply the Program is made by the dealer. When reporting the repair, use "PS4854" as the Part Number and "7755" as the Group Number. If administered before failure, use "56" as the Warranty Claim Description Code and use "T" as the SIMS Description Code. If administered after failure, use "96" as the Warranty Claim Description Code and use "Z" as the SIMS Description Code.
NOTE: Although this Program is to be administered as described above on the Affected Product, parts should be removed from parts stock as soon as possible.
Termination Date
November 30, 1993Problem
The fuel lines on certain 3408 Generator Set, Industrial, and Marine engines may fail. New fuel line groups can be installed that have a longer service life.
Affected Product
Model & Identification Number
3408 (67U12405-15199; 78Z2829-4522; 99U5985-7229)
Parts Needed
Additional Parts Needed For DIT Engines (Non-Aftercooled)
- 5 - 5M2894 Washer
- 1 - 4P8261 Bracket
- 1 - 4P8385 Bracket
- 2 - 5P0537 Washer
- 5 - 0S1571 Bolt
- 2 - 0S1615 Bolt
- 3 - 8T1296 Washer
- 1 - 4P8261 Bracket
Action Required
Parts Stock
Make sure that all 7C6931, 7C6932, 7C6933, 7C6934, 7C6935, 7C6936, 7C6937 and 7C6938 Fuel Lines were removed from parts stock while implementing Product Support Program PS4737.
Affected Product
Remove the existing fuel lines and install the new fuel injection line groups as a group. See the attached rework procedure.
NOTE: Do not over tighten the screws of the metal-to- metal fuel line clamps. Use a 6V6069 Torgue Screwdriver or similar tool to tighten the screw to a torgue of 2.25 N ·m (20 lb in).
Service Claim Allowances
Parts Stock
Refer to the Product Support Program PS4737.
Affected Product
NOTE: This is a 2.2-hour job.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach. (1-Rework Procedure)
Rework Procedure
Refer to the parts list and illustrations. Replace the existing fuel lines and their related parts with the new 6I0030 Fuel Line Group.
NOTE: To insure that the clamp locations are correct, install fuel line group as assembled. In a case where it is necessary to remove the clamps, mark their locations to insure the correct position when assembling.
1. Clean and paint the new 6I0030 Fuel Line Group before proceeding to the job site.
A) Install 5F2807 Plastic Caps and 2F2990 Plastic Plugs on the ends of the lines.
B) Clean and paint the fuel line group.
C) After drying, do not remove the plastic plugs and caps until the fuel line group is ready to be installed on the engine. Transport the fuel line group in it's original shipping box.
NOTE: If the engine to be reworked is non-aftercooled, also clean and pre-paint the new 4P8385 and 4P8261 Brackets.
2. Remove all the mounting bolts from the fuel line bracket at the aftercooler housing on DITA engines or at the 6N1671 Bracket on DIT engines.
NOTE: The 6N1671 Bracket in the vee of the DIT (non- aftercooled) engines is used to support the fuel line brackets. This bracket is part of the 6N1672 Fastener Group, Affected Product not having an aftercooler required a new two piece bracket.
3. Disconnect all the fuel line nuts at the fuel injection pump and at the adapters in the valve cover bases.
4.
a) Remove the old fuel line group.
b) On DIT engines only, remove the 6N1671 Bracket from the vee of the engine and install the new brackets. Illustrations 2 and 3 show how the new brackets are installed. The 4P8385 Bracket and 4P8261 Bracket are the 2 main parts of this group. Five 0S1571 Bolts and five 5M2894 Washers attach the assembly to the block. To align the assembly correctly, three 8T1296 Washers are reguired to shim the brackets to the block (see Illustration 2 Part 2 of 2). Use two 0S1615 Bolts and two 5P0537 Washers to attach the brackets together.
5. Remove the plastic plugs and caps from the 6I0030 Fuel Line Group. Set the new fuel line group in place and hand tighten the fuel line nuts.
NOTE: Do not force the ends of the lines into place and start the fuel line nuts. This puts unwanted strains on the fuel lines. If any of the ends of the individual fuel lines are not square with the bonnets of the fuel injection pump or the adapters in the valve cover bases, gently bend the lines by hand to align the ends before starting the fuel line nuts.
6. Use six 0S0509 Bolts and six 5M2894 Washers to attach the fuel line brackets to the aftercooler housing or on DIT engines, the new brackets installed in Step 4.b.
NOTE: Normally the brackets will fit correctly on the aftercooler housing or the new DIT brackets. If there are gaps, use the washers removed in Step 2 as spacers to fill in the gaps. The purpose of the washers is to prevent the brackets from putting unwanted strain on the fuel lines.
7. Tighten mounting bolts for the brackets.
8. Use the hand priming pump to purge air out of the fuel lines. The fuel line nuts at the adapters in the valve cover bases may need to be loosened to allow air to escape. Hand tighten the fuel line nuts as the air is purged from the lines.
9. Tighten all of the fuel line nuts to a torgue of 40 ± 7 N·m (30 ± 5 lb ft).
10. Wipe up all spilled fuel.
11. Start engine to purge any remaining air and make sure there are no fuel leaks.
12. Shut the engine off and tighten all of the fuel line nuts again to the torgue shown in Step 9.
13. Paint any areas of the fuel lines/brackets as necessary.
Illustration 1
Illustration 2 - Part 1 Of 2 - Top View
Illustration 2 - Part 2 Of 2 - Left Side View
Illustration 3 - Part 1 Of 2 - Front Right View
Illustration 3 - Part 2 Of 2 - Left View