1996/12/23 Caterpillar

Externally Adjusted Relief Valve Used In Steering Control Valve Group{4307,4322}

Usage:

631E (1AB),
651E (89Z),
834B (92Z, 7BR) Wheel Tractors;
836 (3RL, 7FR) Landfill Compactors;
988B (50W),
988F (8YG, 2ZR),
992D (7MJ) Wheel Loaders

Description of Change: An externally adjusted relief valve replaces a plug and shims in the steering control valve group. The externally adjusted relief valve has two advantages:

* A retainer and locknut allow easier, accurate settings for relief pressure.

* Contaminants are kept out of the steering control valve.

Adaptable To: The externally adjusted relief valve replaces the 9S-4187 Plug (6), and shims (7) used in 6E-4031, 6E-5171, and 8J-2318 Steering Control Valve Groups.

This change is effective with 631E (1AB1655), 651E (89Z277) and 834B (7BR566) Wheel Tractors, 836 (7FR230) Landfill Compactors, 988F (2ZR282) and 992D (7MJ562) Wheel Loaders. Earlier machines are adaptable.

This change is also adaptable to all 836 Landfill Compactors, 834B Wheel Tractors, and 988B Wheel Loaders.

Typical Steering Control Valve Group View A: Externally Adjusted Relief Valve (1) 9X-6395 Nut. (2) 9T-7202 Retainer. (3) 133-1480 Spacer. (4) 3K-0360 Seal. (5) 1L-3583 Dowel. View B: Shim Adjusted Relief Valve (4) 3K-0360 Seal. (6) 9S-4187 Plug. (7) Shims.

Caterpillar Information System:

1996/12/23 Cab Heater Efficiency Improved{7304}

1996/12/23 Grapple Rotator Motor Joint Strengthened{5082,6307}

1996/12/23 Rear Axle Oil Level Raised To Improve Axle Lubrication{3013}

1996/12/23 Service Procedures For Special Application Rollers And Idlers Summarized For Track-Type Troctors{4159,4180}

1996/12/23 Longer Bosses Increase Blade Assembly Service Life{5057,6060,6051,6071,7167}

1996/12/16 Improved Fuel Sender Assembly Available {7481}

1996/12/16 Cab Air Conditioner Group Improvements Eliminate Debris {7320}

1996/12/16 Longer Tie Rods For Control Valve Groups {5051,5124}

1996/12/16 Cab Improvements Reduce Vibration {7266}

1996/12/16 Spring Force Adjustment Allows Hydraulic Levers To Remain In Detent Position {5051}

1996/12/16 Sprocket Segments Can Be Reworked To Allow Proper Torque {4155}

1996/12/16 Speed And Direction Lever Improvements Prevent Seizing {1901}

1996/12/23 Larger Washer Used With Tube Clamps On Hydrostatic Transmission Prevents Clamp From Loosening{3218}

1996/12/23 New Temperature Sensors Used Which Prevent False Over Temperature Warnings{1906,1400}

1996/12/23 Ride Control Accumulator Recharging Procedure Changed{5081,5077}

1996/12/23 New Sight Gauge Replaces Former Dip Stick For Improved Visibility Of The Front Implement Hydraulic Tank Oil Level{7479}

1996/12/23 New Rotocoil Assembly Used In Engine Cylinder Head Groups{1109}

1996/12/30 Wiring Harness Routing Changed To Increase Wire Harness Service Life {1408}

1996/12/30 Improved Clapper Spring Available For Pilot Valve Groups {5059,5125,5126}

1996/12/30 Supplement To Service Manual Module; "Differential Lock-Relief Valve Pressure Check" {3264}

1996/12/30 Service Brake Adjustment Procedure Improves Application Pressure And Performance {4251,4269}

1996/12/30 Systems Operation Testing & Adjusting, 966F & 966F Series II Wheel Loader Air System And Brakes, Service Manual Module Available {0374,4250}

1996/12/30 New Hose Assemblies Are Compatible With The Extended Life Coolant (ELC) And Provide Increased Service Life {1380,1395}

1996/12/30 New Thumb Screw Improves The Ability To Secure The Air Filter Grate To The Cover Assembly {7301,7308,7251}