1982/04/19 Caterpillar

New Relief Valve For Steering System Is Easier To Adjust{4322}

Usage:

768C ( 2X341-Up ),
772 ( 64W159-Up ),
776 ( 14H162-Up ) Tractors;
769C ( 1X2231-Up ),
773B ( 63W912-Up ),
777 ( 84A969-Up ) Trucks

Description of Change: A new pilot-operated relief valve group is used in the steering system for the above machines. See Illustration 1.

The cap used in the new valve is drilled and tapped to permit installation of a plug and a plunger with threads. To adjust the new valve, the serviceman removes the plug and turns the plunger in or out with a hex wrench. See Illustration 2.

The former valve group was adjusted by the removal and installation of shims; it had to be disassembled for adjustment.

Adaptable As: The new 4T844 Relief Valve Group is a direct replacement for the former 9J5390 Relief Valve Group which is canceled.

Illustration 1. Location of the 4T844 Relief Valve Group.

Illustration 2. Comparison of the new and former valve groups.

Caterpillar Information System:

1982/04/19 Improvements Made To 6V3000 Sure Seal Repair Kit{0611,1408}

1982/04/19 New Brackets Used In Front Floodlamp Lighting Group{7309}

1982/04/12 Add Lubricant For Motor Shaft Bearing{5058,5200}

1982/04/12 Use 6V4938 Seal Guide For Seal Installation On Hydraulic Cylinder Rod{0622,5458}

1982/04/12 Correct Position Of Shims In Blade Lift And Centershift Cylinder Groups{5102,5223}

1982/04/12 Use Correct Size Bolt To Install 5P9736, 6V2156 Or 6V2157 Link Brackets{0644}

1982/04/12 Make Sure Hydraulic Pumps Are Installed Correctly{5055,5070,5073}

1982/04/12 New Spring Used In Accumulator Charging Valve Group For Brakes{4264}

1982/04/12 Lock Screw For Threaded Crown On Hydraulic Cylinders No Longer Used{5000}

1982/04/12 Use Correct Part Numbers For Main And Connecting Rod Bearings{1230,1203,1219}

1982/04/12 New Clearance Specification Used In Torque Converter{3101}

1982/04/05 New Outer Duo-Cone Seal Groups Used In Service And Parking Brake Groups{4208,4251,4267}

1982/04/19 New Broken Link Spring Used In Governor{1264}

1982/04/19 New Seal In Transfer Gear Group{3176,3159}

1982/04/26 Check Valve Prevents Release Of The Parking Brake{5220,4267}

1982/04/26 External Reinforcements Can Be Added To Main Frames{7051}

1982/04/26 New 6V4920 Cable Cutter Group Available{0663}

1982/04/26 Improved Relief Valve Guide Decreases Maximum Oil Pressure During Cold Weather Starts{1315,1304}

1982/04/26 New Pins Used In Dump Body Support Assembly{7258}

1982/04/26 Caliper-Type Disc Brakes Now Used On Front Wheels{4250,4205,4208}

1982/04/26 Expansion Tank Changed To Permit Installation Of Water Level Gauge{1354,7470}

1982/05/03 6V4960 AC Current Probe Will Measure Current Easier{0652}

1982/05/03 Use New Special Instruction To Install 5P6595 Insert In Cylinder Liner Seats{1216,0621}

1982/05/03 New 6V4950 Injection Line Speed Pickup Group Used With 6V2100 Multitach{0651}