PIN 0544672 - Caterpillar

Solution
Caterpillar is aware of this problem, but a permanent repair has not been identified. As an interim solution follow the rework procedure given below.
Do not operate or work on this product unless you have read and understood the instruction and warnings in the relevant Operation and Maintenance Manuals and relevant service literature. Failure to follow the instructions or heed the warnings could result in injury or death. Proper care is your responsibility.
This procedure communicates troubleshooting and inspection guidelines which may extend the life of the components. This document also provides recommendations to communicate information back to Caterpillar which will assist in the final resolution.Order of Component Failure
Illustration 1 g06335117
(1) 379-9017 Brackets
(2) 377-7376 Adapter
(3) Bolts
(4) 550-0794 Bracket and 550-0795 Plate As
(5) 508-6705 BracketNote: The two piece bracket assembly (4) is currently a one piece bracket.First the 379-9017 Brackets (1) fail.Second the 377-7376 Adapter Y-Pipe (2) fails.Note: Bolts (3) were failed / missing at several sites experiencing these failures. Investigating to determine if this is the initial failure.Perform Regular Inspections
When possible, perform regular inspections of all brackets and hardware shown above.Note: Inspect components often, daily if engine has had previous failures.Document if either of the bolts (3) have broken prior to the 379-9017 Brackets starting to crack.When failures of any of these components occur, take pictures of the brackets, Y-pipe, and bolts.Provide the information to your Cat dealer Technical Communicator (TC) along with this Technical Information Bulletin (TIB) and CPI Number 412887.Communicate any information to Caterpillar Customer Service through the Dealer Solutions Network (DSN).Keep all failed parts including pieces of bolts for return to Caterpillar service via the Send It Back (SIB) process.
Illustration 2 g06335069
(1) 379-9017 BracketInspect the 379-9017 brackets (1). If cracks are observed, replace immediately with new 379-9017 bracket.Note: Replacing the bracket at first signs of cracking has prevented subsequent 377-7376 Y-Pipe failures at some sites.Repair Information
Illustration 3 g06335776
(3) Bolts
(4) 550-0794 Bracket and 550-0795 Plate As
(5) 508-6705 BracketIf the bolts (3) are broken, and the holes in the one piece bracket do not line up with the holes in the flowerpot flange replace the one piece bracket with the two piece assembly (4.).Contact Caterpillar Customer Service through the DSN to acquire the following parts:
Table 1
New Parts for Two Piece Bracket Assembly (4) Quantity
550-0794 Bracket 1
550-0795 Plate As 1
0S-1585 Bolts (1/2-13X1.5-IN) 2
5P-8245 Hard Washers 2
7D-1649 Hard Washers 2
1F-7958 Full Nuts 2
0L-1329 Bolts 2 Note: If the bolts are not broken, it is highly recommended to replace the existing bolts with the 0L-1329 Bolts if not already equipped.Torque the two 0L-1329 Bolts to 105 20 N m (77 15 lb ft)Install the 508-6705 Bracket (5) on the left-hand side.
Table 2
New Parts for Installing the 508-6705 Bracket (5) Quantity
508-6705 Bracket 1
092-9012 Spacers 2
5P-8247 Hard Washers 2
0S-1625 Bolts 2 Side near H-frame bolts onto the existing 6V-1525 Taperlock Studs on the exhaust tee.Torque the nuts to 47 9 N m (35 6 lb ft)