BOLT 0L1178 - 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 "PS8876" 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
December 31, 1998Problem
Some valve cover seals may deteriorate with heat and age and allow oil leakage. A new seal is available that will provide a better service life.
Affected Product
Model & Identification Number
Group 1
D11N (74Z1-1153 4HK1-636 )
D11R (8ZR1-346, 8ZR354)
776B (6JC1-109)
776C (2TK1-115)
776D (5ER1-76)
777B (4YC1-1867)
777C (4XJ1-1124)
777D (3PR1-155, 3PR160, 3PR165)
5130 (5ZL1-104)
Engine Serial Numbers
(99W1-3510 7YG1-1911 2GR1-300 4ZL1-361 5TL1-175 )
Group 2
784B (5RK1-25)
785 (8GB1-698)
785B (6HK1-640)
Engine Serial Numbers
96Z1-9184WJ1-822 5EL1-124 6FL1-103 )
Affected Product Cont.
Model & Identification Number
Group 3
789 (9ZC1-678)
789B (7EK1-499, 7EK504)
793 (3SJ1-57)
793B (1HL1-525)
793C (4AR1-79)
994 (9YF1-200)
5230 (7LL1-66)
Engine Serial Numbers
54Z1-11632PK1-1268 7TR1-216 6CL1-219 7CL1-353 )
Parts Needed
Group 1
8 - 1345958 Seal-O-Ring (for 3508 MUI Engines)-OR-8 - 1345959 Seal-O-Ring (for 3508 EUI Engines)Group 2
12 - 1345958 Seal-O-Ring (for 3512 MUI Engines)-OR-12 - 1345959 Seal-O-Ring (for 3512 EUI Engines)Group 3
16 - 1345958 Seal-O-Ring (for 3516 MUI Engines)-OR-16 - 1345959 Seal-O-Ring (for 3516 EUI Engines)Action Required
This rework can be completed in conjunction with another service letter or machine maintenance on the Affected Product.
Remove all the valve cover seals and replace the old orange seal with the new black seal. Use the 1345958 Seal to replace the 4W1596 Seal on MUI Engines. Use the 1345959 Seal to replace the 2W2072 Seal on EUI Engines.
Caterpillar recommends that all valve covers be updated at the same time.
Service Claim Allowances
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.