1988/12/12 Caterpillar

New Operator Monitor Group Used{7490}

Usage:

Challenger 65 Tractors

A new 7X6147 Operator Monitor Group is used on Challenger 65 Tractors 7YC600-Up. This group replaces the former 7T1954 Operator Monitor Group. A new OR5991 Remanufactured Control Group is also available to replace the former OR5734 Remanufactured Control Group.

The new monitor group provides improved serviceability with a harness that disconnects at the panel and improved system voltage monitoring. If system voltage is 15.6 volts or above, the "Electrical System" LED comes ON. (On the former monitor group, this LED is called "Alternator" and only comes ON if the alternator output is zero.) The new monitor group also has the capability to display actual system voltage at any time. See Operation and Maintenance Manual, SEBU6237-01.

To replace either of the former groups on earlier Challenger 65 Tractors, install a new 9W0675 Harness Assembly and either of the new groups.

Caterpillar Information System:

1988/12/12 Revised Instructions For Installation of New Maintenance Free Batteries{1401,1400}

1988/12/05 Operation Of Feeder Sensor Control{8216}

1988/12/05 Improved Air Conditioner Thermostat Switches Have Tin-Plated Internal Parts{7320}

1988/12/05 Hydraulic Pressure Settings For Backhoe Loaders{5050,5450}

1988/12/05 Improved Coupler Pin Helps Prevent Cylinder Rod Bending{6129}

1988/12/05 New Air Tank Drain Valve Used{4250,4272}

1988/11/28 More Charts And Decals Available For Lubrication And Maintenance Intervals {0374,0375,7500}

1988/11/28 Stronger, Longer Ring Gear Retainers For Final Drives {4054,4084}

1988/11/28 Improved Wheel And Longer Bolts Provide Better Retention Of Front Brake Disc {4255,4201}

1988/11/28 New Mounting Pin Assemblies For Blade Tip Cylinder {5106}

1988/11/21 One-Piece Tappet (Follower) Used In 11 mm (Type 2) Fuel Injectors{1290}

1988/11/21 New Oil Seal For Water Pumps Has Hydrodynamic Grooves{1361,1389}

1988/12/12 Parts Needed If Air Compressor Tubes Replaced{4257,1803}

1988/12/12 New Switch For Back-Up Alarm{7406}

1988/12/12 New Solenoid Valve For Rotor Lift System{8245}

1988/12/12 New Mounting Bolts Used In Aftercooler Housings{1063,1058}

1988/12/12 Maintenance Procedure Extends Service Life Of Exhaust Manifold Studs{1050}

1988/12/12 New Alternator Drive Pulley Has Hardened Wear Sleeve; New Seal Used On Pulley{1425,1357}

1988/12/12 Oil Cooler Bypass Elbow Changed To Prevent Bypass Valve Seizure{1314,1318}

1988/12/19 New Material Used For Rotating Seal Rings In Some Power Shift Transmissions, Steering Clutches And Torque Converters {3101,3150,4100}

1988/12/19 Cold Weather Readiness Checks {1456,1250}

1988/12/19 New Circle Drive Gerotor Motor Groups Provide Higher Torque To Circle Drive {5082}

1988/12/19 New Brake Disc Assemblies, Axle Lubricant Reduce Brake Chatter {3278,4255}

1988/12/19 Stronger Spacers Can Be Used On Stabilizer Street Pads {6505}