156728-2600 ZEXEL 9 423 614 120 BOSCH SHIM 9423614120 1567282600 1157480120

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 must be administered as soon as possible. When reporting the repair, use "PI3841" as the Part Number, "7751" as the Group Number, "56" as the Warranty Claim Description Code and "T" as the SIMS Description Code. Exception: If the repair is done after failure, use "PI3841" as the Part Number, "7751" as the Group Number, "96" as the Warranty Claim Description Code, and "Z" as the SIMS Description Code.
Completion Date
July 31, 1996Termination Date
January 31, 1997Problem
Shot peening on some 3500 Diesel Cylinder Heads extends too far into the injector bore. This may cause the top injector o-ring to be cut or torn on installation.
Affected Product
Model & Identification Number
777C (4XJ844, 4XJ846-872, 4XJ879, 4XJ883, 4XJ885)
785B (6HK483-489)
789B (7EK355-364, 7EK367)
793B (1HL359-367)
3512 (1LM67-73 4WJ649 )
3512B (8RM126-129 4TN40 )
3516 (4XF605, 4XF606 5SJ392-397 2PK918 )
3516B (8CN134 8KN69 , 8KN70 7RN253-259 )
Parts Needed
Dealers will need to order parts for this Program.
1 - 8J8725 Seal-O-Ring (per cylinder)1 - 8T7767 Wheel-Level (per engine)1 - 8T7768 Mandrel (per engine)Action Required
1. Remove the valve cover, rocker arm assembly and fuel injector.2. Inspect the top injector o-ring seal for damage. If damaged, polish the upper injector bore area using an 8T7767 Polishing Wheel and an 8T7768 Mandrel. Install a new 8J8725 O-Ring Seal on each injector.3. Install the injector using clean engine oil in the injector bore and on the o-rings.4. Install rocker arm assembly and reset valves and injector. Install valve covers.Owner Notification
U.S. and Canadian owners will receive the attached Owner Notification.
Service Claim Allowances
Parts Disposition
Handle the parts in accordance with your Warranty Bulletin on warranty parts handling.
MAKE EVERY EFFORT TO COMPLETE THIS PROGRAM AS SOON AS POSSIBLE.
Attach.(1-Owner Notification)Copy Of Owner Notification For U.s. And Canadian Owners