1991/01/07 Caterpillar

New Boost Line Hose Assemblies Withstand Higher Temperatures{1081,1057,1088,7554}

Usage:

3406 ( 4FD, 1RK ),
3408 ( 6NB ),
3412 ( 7DB ) Spark-Ignited Engines

Description of Change: Two new hose assemblies are used in the exhaust bypass groups. The new hose assemblies are made with an improved material which is designed to resist the intense heat from exhaust gasses. The former hose assemblies could deteriorate from the high temperatures.

Adaptable To: The new 4P0310 Hose Assembly is a direct replacement for the former 9N3371 Hose Assembly (not canceled) used in the 7C9729, 9Y9832, and 7W9998 Exhaust Bypass Groups (not serviced) for 3406 Spark-Ignited Engines. This change is effective with 3406 (4FD199, 1RK1) Spark-Ignited Engines.

The new 4P1839 Hose Assembly is a direct replacement for the former 9L5158 Hose Assembly (not canceled) used in the 2W2045 (3408) and 7W5847 (3412) Exhaust Bypass Groups (not serviced). This change is effective with 3408 (6NB797), and 3412 (7DB572) Spark-Ignited Engines.

These changes are also adaptable to first production.

Caterpillar Information System:

1991/01/07 Checking Crankshaft Journal Surface Hardness On Remanufactured Crankshafts{1202}

1990/12/24 New Tube And Bracket Provide Clearance For Alternator{1380,1405}

1990/12/24 Auxiliary Oil Filter Groups Used To Increase Oil Capacity And Extend Oil Change Interval To 750 Hours{1318,7534}

1990/12/24 Oversized Intake And Exhaust Valve Seat Inserts Available For Spark-Ignited Engine Heads{1103}

1990/12/24 New Seals Available For Parts Service Of Noncurrent Water Lines Group{1380,1155,1378}

1990/12/24 New 3E0020 Vehicle Speed Buffer Used{1914,1900}

1990/12/24 Update Information For Exhaust Manifolds{1059}

1990/12/24 Air Pressure Settings For Pneumatic Selector Control Valve On Reintjes® Marine Transmissions{3313}

1990/12/24 Installation Of Zinc Rods In Caterpillar Marine Engines{1350,1388}

1990/12/24 Incorrect Specification For Tightening Turbocharger Compressor Nut In Service Manual For 3306B Diesel Truck Engine, SEBR0545-01{1052}

1990/12/24 Sealed Alternators Available For Earthmoving Applications{1405}

1990/12/17 New Ether Starting Aid Groups Available{1456}

1991/01/14 4C8753 Extended Collet Available; Problems With 8T1002 Probe For Fuel Setting{0782}

1991/01/14 Air Compressor Manifolds Are No Longer Available{1803}

1991/01/14 New Battery Load Tester Available To Service Six, Eight, And 12 Volt Batteries{0785,1401}

1991/01/28 New Bracket Assemblies Used In Lifter Group{1209,1281}

1991/01/28 Special Instruction SEHS9298 Gives Installation And Maintenance Information For Gaseous Fuel Filters{1261,1262}

1991/01/28 New Top Piston Ring Improves Wear Resistance{1215}

1991/01/28 Be Sure To Check Inlet Valve Rotocoils After An Engine Overspeed{1109,1105}

1991/02/11 New Sleeve-Type Bearings Give Better Carburetor And Governor Control{1265,1266}

1991/02/11 New Altronic V Magneto Used{1552}

1991/02/11 New Water Temperature Regulator{1355}

1991/02/18 Be Sure To Remove All Air From The Fuel System On A Truck That Has Run Out Of Fuel, Had The Fuel Filter Changed, Or Had The Governor Removed{1250,1256,1261,1264,1274}

1991/02/18 New Front Crankshaft Seal Used{1160,1202}