1991/09/30 Caterpillar

New Piston Crown And Piston Skirt Used In Basic Piston Group; New Cooling Jet Used In Cylinder Block Group{1214,1331}

Usage:

3508 1ZF, 3512 2YF, 3516 4XF High Horsepower Standby Generator Set Engines

Description of Change: A new piston crown made of forged steel is used in the basic piston group. The former crown was made of cast steel. The new forged steel piston crown is stronger and tougher than the former crown. A new piston skirt and piston cooling jet assembly is used with the new crown because of differences in the outline of the new and former crown.

Adaptable To: The new and former components are listed in the chart.

The new components are in effect with High Horsepower Generator Set Engines as follows:

3508...1ZF556

3512...3YF504

3516...4XF317

When used together in a cylinder, the new components can be used as direct replacements for the former components in earlier engines.

NOTE: The new and former crown, skirt and cooling jet can not be mixed. If mixed the result can be contact between the crown and skirt, or between the skirt and jet. This could result in damage to the crown, skirt, and jet.

Caterpillar Information System:

1991/09/30 Use 7E5888 Fuel Injection Pump Housing As A Service Replacement For Pre 1991 Fuel Injection Pump Housings{1253}

1991/09/30 Air Filter Maintenance{1051,1054}

1991/09/30 Compression Ratio Increased On Remanufactured OR1094 & OR1095 Engines To Reduce Amount Of White Smoke On Cold Weather Start-Ups{1000,1254,1290}

1991/09/30 "Off-Size" Bearing Kits Available For Parts Service{1052,7551}

1991/09/30 Updated List Of Charts And Decals Available For Lubrication And Maintenance Intervals{0374,0375,7500,7557,7581}

1991/09/30 Excessively Long Bucket And Ripper Tips May Cause Failures{6800}

1991/09/23 New Auxiliary Water Pump Groups Used{1371}

1991/09/23 New Pickup Assembly In Sump Pump Group Attachment Removes More Oil From Oil Pan{1324,1302}

1991/09/23 New Piston Skirt Used In Piston Group{1214}

1991/09/23 New Tube Assembly Used In Exhaust Bypass Group Attachment{1057}

1991/09/23 Sintered Bronze Replacement Bushings For Delco-Remy Electric Starting Motors Do Not Require Machining{1453,1454,1465}

1991/09/23 Turbocharger Bearings Available For Garrett (Formerly AiResearch) Turbochargers Changed{1053}

1991/10/07 Assembly Procedure For Duo-Cone Seals Changed{7561,0645}

1991/10/07 New SR 4 Generator Rewind Data Available{4450}

1991/10/14 New Locking Bolt Used In Flywheel Groups{1156}

1991/10/14 New Teflon Coated 4P9388 Cylinder Seal Available{1216}

1991/10/14 New Components Used In Fuel Injection Pump Groups{1290}

1991/10/14 7S3161 Valve Lifter Has Three Different Designs{1209}

1991/10/14 No Gaskets Used With Aluminum Flywheel Housings{1157}

1991/10/14 New Piston Pin Retainer Used{1225}

1991/10/14 End Clearance Specification Changed For Front Shaft In Fuel Injection Control{1251,1258}

1991/10/21 New Oil Pump Used As Service Replacement {3310}

1991/10/21 How To Repair Oil Leaks Between Front Housing And Spacer Deck {1221}

1991/11/11 Computerized Monitoring System (CMS) Has Improved Electrical System Monitoring{7400}