1998/04/06 Caterpillar

Spools And Valves In The Main Hydraulic Control Valve Are Now Serviceable {5051}

Usage:

311 (9LJ, 5PK, 2KM),
312 (6GK, 7DK, 6BL) Excavators

Description of Change: The spool assemblies and the valve groups in the main hydraulic control valve are now serviceable. The serviceable spool assemblies and valve groups are used to improve boom and stick movements.

Adaptable To: The parts listed in the chart are now serviceable effective with the 312 (6GK1561-Up, 7DK6201-Up) Excavators. These parts are also adaptable to other 312 (6GK1-1560, 7DK1-6200, 6BL) Excavators. For part numbers and location information, refer to the chart and the illustration.

The 127-5977 Repair Kit which improves stick control is now serviceable. The kit is adaptable to all 311 (9LJ, 5PK, 2KM) Excavators.

See chart for serviceable parts identification.

(A) Stick 2.

(B) Boom 1.

(C) Stick 1.

Caterpillar Information System:

1998/04/06 Support Plates Improve Track Frames {4151,4154}

1998/04/06 New Push Rods In The Pilot Control Valve Improve Service Life {5059,5465,5466}

1998/03/30 Service Interval Change For Balderson/Caterpillar Hydraulic Hammers {5488}

1998/03/30 Use 136-3642 Crimp Tool Group For 4C-9900 And 6V-4900 Presses {5057}

1998/03/30 Use 1U-6189 Lamp Tool For Removal And Installation Of Small Control Panel Bulbs {1400,0709}

1998/03/30 Stronger Injector Hold Down Bolt Used In Fuel Injection Pump Groups {1290}

1998/03/30 Use Measuring Tools For Crimp Diameter {0700}

1998/03/30 Use 137-2700 Bore Welding Group (110V), 138-8215 Bore Welding Group (110V With Auto-Skip), 138-8212 Bore Welding Group (220V) And 138-8213 Bore Welding Group (220V With Auto-Skip) For Building Up Worn Or Damaged Bores {0672}

1998/03/30 Use 9U-6803 Tester For Hydraulic Cylinders {7562}

1998/03/30 Use 7X-1703 Adapter Group For Mounting 7X-1700 Communication Adapter On 8T-8697 ECAP {1900,0781}

1998/03/30 Use 126-3993 Test Adapter To Test And Adjust Travel Motor Destroke Point {4351}

1998/03/30 Use FT2534 Seal Installer To Install Swing Drive Housing Seal {5459}

1998/04/06 Magnet Used To Secure Electric Panel Door During VIMS Real Time Analysis Procedure {1417,7301}

1998/04/06 New Line Relief Valve Prevents Seal Failure And Loss Of Line Relief Valve Pressure {5080,5090,5117}

1998/04/06 Track Roller Break In And Travel Procedures {4154,4159,4180}

1998/04/06 New Butyl Cab Mount Used To Reduce Cab Vibration {7260}

1998/04/06 Further Improvements To Retention System For Excavator Tips And Couplers {6500,6515,6537,6800}

1998/04/06 Carbody Side Plates Reinforced To Increase Service Life {7062}

1998/04/06 Improved Duct Assembly Enhances Air Conditioning Of Cab {7309,7320}

1998/04/13 New Relief Valve For Main Hydraulic System Improves Maintaining Pressure Setting {5069}

1998/04/13 Correction To Service Manual Modules SENR6059 And SENR1371 {7601,7603}

1998/04/13 Improved Rod In Bottom Dump Cylinder Group For Bucket {5457}

1998/04/20 Optional Valve Spool Kits Are Available For The Pilot Valve Group To Modify The Response Of Implement Controls{5059,5462,5465,5466}

1998/04/20 Improved Ground Engaging Tool (GET) Pin And Retainer Assembly Are Available{6805}