MANIFOLD-EXHAUST 1078108 - Caterpillar

Caterpillar: Confidential Yellow
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.
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 "PS4075" 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.
Termination Date
July 31, 1998Problem
Intake and exhaust valve bridges need to be replaced on certain C-10, C-12, 3176B, 3176C and 3196 Engines and Challenger 75D and 85D Agricultural Tractors.
Affected Product
Model & Identification Number
C-10 (2PN3679-4632)
C-12 (1YN5561-7604)
3176B (9CK32686-32702 9WK784-802 3NL454-486 )
3176C (2AW212, 2AW213)
3196 (2XR522-637 1DW480 )
75D (5AR391-483)
85D (4GR551-682)
Parts Needed
Non Jake Brake Engines
12 - 1442913 Bridge Assembly Jake Brake Engines
6 - 1442913 Bridge Assembly 6 - 1442914 Bridge AssemblyAction Required
Replace all valve bridges with new parts: 1442913 (standard), 1442914 (exhaust with hole for Jake Brake screw).
If the engine has Jake Brake, transfer six Jake Brake screws from the old exhaust valve bridges to the new exhaust valve bridges.
See the attached rework procedure.
Service Claim Allowances
Labor Breakdown By Cab Type Marine, Industrial, and Challenger times may include additional labor time (reasonable/actual) for difficult engine access. Claim these times using 1121-500.
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
Attach.(1-Rework Procedure)Rework Procedure
All references to Service Manuals relate to C-10 and C-12 Truck Engines.
1. Check to see if rework was completed prior to shipment: If "QK" is stamped on block near serial number plate, then do not rework.If not stamped, then proceed with the rework procedure.2. Remove valve covers. Reference the Disassembly & Assembly Manual, SENR1002-01.3a. Put #1 piston at top center (TC) on the compression stroke. Replace bridges on the following cylinders: Follow the Replacement/ResetGuidelines listed below.
3b. Rotate flywheel 360 degrees to put #6 piston at top center (TC) on the compression stroke. Replace bridges for the following cylinders: Follow the Replacement/ResetGuidelines listed below.
Replacement/Reset Guidelines
Transfer Jake Brake actuator screws from old to new exhaust bridges.
Reference January 1994 Truck Engine News or November 1996 Tech Tips, LEVN3899, for correct procedure to set pin depth so that bridges will be level when installed on engine.
Set valve lash as follows:
Reference Systems Operation Testing & Adjusting Manual, SENR6593-01.
Adjust Jake Brakes as follows:
C-10 Truck = 0.64 mm (0.025 in)C-12 Truck = 1.14 mm (0.045 in)Reference Systems Operation Testing & Adjusting Manual, SENR6593-01.