1997/09/22 Caterpillar

Additional Relay Valve Used In Automatic Retarder Arrangements To Improve Automatic Retarder Control (ARC) System Reliability{4005,4133,3120}

Usage:

771D (6JR),
775D (6KR) Quarry Trucks;
776D (5ER) Tractor;
769D (5TR),
773D (7ER),
777D (3PR) Off-Highway Trucks

SUPPLEMENT: MAY 11, 1998

Service Magazine SEPD0383; Article 16, Page 28; September 22, 1998; "Additional Relay Valve Used In Automatic Retarder Control (ARC) System Reliability."

Information listed in the former charts was incorrect. The corrected charts should read as follows:

--------------- END SUPPLEMENT ---------------

Description of Change: Automatic retarder arrangements in some off-highway trucks have been redesigned to include an additional relay valve which will operate exclusively for ARC actuation. The additional relay valve will provide improved reliability of the ARC system.

Adaptable To: The new automatic retarder arrangements are listed in Chart 1 with their effective model numbers. These changes are adaptable to all previous models using the custom product retrofit kits listed in Chart 2. Custom product literature for ARC retrofits will be announced in a service magazine soon and will be available through normal literature ordering channels. Retrofit kits and instructions can be ordered through Decatur Custom Products by contacting:

* Wayne Thais - (217) 475-4310

* Bill Burg - (217) 475-4230

Caterpillar Information System:

1997/09/22 Improved Braze Joint On Brake Oil Coolers Reduce Possibility Of Leaks{1365}

1997/09/22 Retrofit Kits Available For Rear Axle Lube And Filtration{4051,3258,3260,7601}

1997/09/22 New Differential Pinion Bearing Setting Tool And Procedure Available{3258}

1997/09/22 Four Wheel Drive All-Wheel-Steer Brakes{4250,4257}

1997/09/22 Engine Oil Filter Access Changed For Improved Serviceability And Turbo Life{1306}

1997/09/22 Charcoal Air Filter Available Reduces Odors From Outside Air{7309,7320,7342}

1997/09/22 Non-Rotating Drawbar Pin Extends Service Life{7105,7119}

1997/09/15 Cold Cylinder Cutout Strategy Added To The Electronic Control Module (ECM) Software {1902}

1997/09/15 New Temperature Regulators Provide More Accurate Opening And Closing Temperatures {1330,1355}

1997/09/15 Correction To Fan Speed And Pressure Test Procedure {1356,1386,1387}

1997/09/15 New Front Axle Bevel Gear Set Improves Service Life {3258,3013,3256,3278}

1997/09/15 New Rear Axle Differential Group Bevel Gear Set Improves Service Life {3258,3013,3256,3278}

1997/09/22 Larger Clamps Improve Hose Installation In 124-8216 Water Lines Group In 793C Off-Highway Trucks{7554}

1997/09/22 Hydraulic Control System Improvements Reduce Retarder Response Time{1019}

1997/09/22 Transmission Control Switches Serviceable{3171}

1997/09/22 Correction To Lift Arm Repair Chart{6107,6119}

1997/09/22 New Kit Extends Life Of Rolling Hoses{6460}

1997/09/22 Improved Piston Crown Assembly Used In The Rod And Piston Group{1214}

1997/09/22 New Piston Crown Improves Service Life{1214}

1997/09/29 Strap Added To Retain Torsion Spring In Steering Control Group{4343}

1997/09/29 New Flushing Valve Group Eliminates Possible Shut-Down Of All Wheel Drive System{5050}

1997/09/29 New Cylinder Groups And Tube Assemblies For Stabilizers With Flip Over Pads{5468}

1997/09/29 Improvement To Air Conditioning Lines Group In The 793C Off-Highway Trucks For Reduced Engine Removal And Installation Time{1808,1809}

1997/09/29 Torque Converter Tubing Improvement Provides Clearance {3103}