1997/08/11 Caterpillar

New Cartridge Group For Steering Accumulator Charging Valve Group Prevents Binding Of Cartridge Piston{4331,5081}

Usage:

793C (4AR),
793B (1HL) Off-Highway Trucks

Description of Change: A new accumulator charging valve group replaced the former accumulator charging valve group in the steering system. A new "cutout" pressure cartridge, in the new accumulator charging valve group, has a longer piston that will not bind in the cartridge body.

Adaptable To: The new 139-9048 Accumulator Charging Valve Group replaces the former 120-4622 Accumulator Charging Valve Group. The new accumulator charging valve group is effective with 793C (4AR138) Off-Highway Truck.

All 793B (1HL) and earlier 793C (4AR1-137) Off-Highway Trucks are adaptable by replacing the former 120-5315 Cartridge Group with the new 139-9049 Cartridge Group, or replacing the former 120-4622 Accumulator Charging Valve Group with the new 139-9048 Accumulator Charging Valve Group.

New 139-9048 Accumulator Charging Valve Group (1) New 139-9049 Cartridge Group (cutout pressure). (2) Piston (Long). (3) Former 120-5315 Cartridge Group (cutout pressure). (4) Piston (Short).

Caterpillar Information System:

1997/08/11 Serviceable Parts for 4 Wheel Drive Front Axle Steering Cylinder{4303}

1997/08/04 VIMS-PC Compatibility{7601}

1997/08/04 Disassembly And Assembly Supplement Available For Limited Slip Differentials{3263}

1997/08/04 Reliability And Fatigue Strength Improved In Connecting Rod{1218,1219}

1997/08/04 Tractors And Trucks Include Filters For Early Hour Oil Changes To Ensure Clean Hydraulic System{5068,3067,4295,4070,4332,5056,1379,3103,3154,4257}

1997/08/04 Duo-Cone Seal Assemblies With A Toric Available For Tractors And Trucks{4006,7555,4251,7561}

1997/08/04 Improvement Made To Wiring Group For Reduction In 793B Engine Removal And Installation Assembly Time{1408}

1997/07/28 Protection Of Unsealed Electrical Terminations For Machines Used In Corrosive Applications{1400}

1997/07/28 Required Maintenance Of Air Cleaner Dust Valves{1050,1051,1055,1068}

1997/07/28 Correct Position of Shaft Seals And New Plug For Seal Drain Cavity In Pump Groups Improves Service Life{4306,5073,5083}

1997/07/28 New Support Spring Has Improved Service Life{4304}

1997/07/28 Correction to Steering Pump Illustration{4324}

1997/08/11 Ride Control Accumulator Recharging Procedure{5077,5050,5057}

1997/08/11 Improved Type 2 Brake Control Group Components{4258,4257,4262,4269}

1997/08/11 Correction To Operation & Maintenance Manual, SEBU6955{0375}

1997/08/11 Supplement To Service Manual, SENR5890, Electronic Transmission Control System{1408,3168}

1997/08/11 Improved Switches Now Used To Prevent Open Contacts{1423}

1997/08/18 Improved Three-Point Hitch Rockshaft Seal And Wear Ring Prevents Dirt Packing {7120}

1997/08/18 Improved High Ambient Cooling Configuration Available {1205,1350,1357,1384}

1997/08/18 New Flagpin Retention Method Improves Torsional Strength {7120}

1997/08/18 Four Wheel Drive All-Wheel-Steer Dead Engine Brake Inspection {4250,4265}

1997/08/18 Information Is Corrected On The 793C Engine Information Plate {1000,7557}

1997/08/18 New Engine Arrangements For High And Low Altitude Applications {1000}

1997/08/18 Changes To VIMS Truck Payload System {7601}