FLANGE-EXHAUST 1336479 - Caterpillar

PROBLEM
The 261-5604 or 165-3935 Bolts (depending on previous repairs) for the aftercooler, as directed for use in TIBU5975, are experiencing failures. When these bolts fail, it will typically lead to a boost leak.
AFFECTED PRODUCT
Model Identification Number
793D FDB00109, 243-248, 251, 263-266, 288-291, 296, 314-315, 317-318, 332-334, 354-356, 359, 367-368, 372, 379-382, 394-396, 402, 404-405, 409, 415-418, 420-425, 432-433, 447-449, 456-457, 461-462, 469-472, 475-477, 484-485, 497-500, 502-506, 514-518, 524-527, 534-538, 546, 580, 613, 618, 623, 629, 640, 645, 649, 653, 657, 659, 661, 663, 671-679, 685, 731-733, 739-740, 759, 761, 772, 775-776, 783, 789-790, 802-806, 810-813, 825, 847-850, 875-878, 1369-1370
PARTS NEEDED
Qty
Part Number Description
12 3767740 BOLT-HEX HEAD
In order to allow equitable parts availability to all participating dealers, please limit your initial parts order to not exceed 32% of dealership population. This is an initial order recommendation only, and the ultimate responsibility for ordering the total number of parts needed to satisfy the program lies with the dealer.
ACTION REQUIRED
Replace the existing 261-5604 or 165-3935 Bolts with new 376-7740 bolts to prevent fatigue failures. The 376-7740 bolts are made from a more thermally compliant material for high temperature applications. Reuse the washers and spacers. There are 12 bolts per engine. Retightening this bolted joint with new hardware will reduce the occurrence of fatigue failures of the bolts resulting in boost pressure leaks.
Use the following tightening procedure when you install the new hardware for the aftercooler. Refer to Image 1 for the bolt locations, and Image 2 for the tightening sequence.
1. Tighten the bolts in the numerical sequence to 24 Nm (18 lb ft).
2. Tighten the bolts again in the numerical sequence to 47 Nm (35 lb ft).
Image 1 Bolt Location - (1) 376-7740 Bolts
Image 2 Tightening Sequence
Image1
Image2
SERVICE CLAIM ALLOWANCES
Product smu/age whichever comes first Caterpillar Dealer Suggested Customer Suggested
Parts % Labor Hrs% Parts % Labor Hrs% Parts % Labor Hrs%
0-16000 hrs,
0-20 mo 100.0% 100.0% 0.0% 0.0% 0.0% 0.0%
This is a 3.0-hour job
If there has been a previous repair, part age/hours will apply. Retain a copy of the previous repair invoice in the dealer's records for audit purposes, and specify repair date and machine hours in the "Additional Comments" section of the warranty claim.
This program is a one-time only application per affected Off-Highway Truck serial number.
PARTS DISPOSITION
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.