1985/02/18 Caterpillar

Increased Preload Used In Air Shutoff Actuators{7400,7418}

Usage:

All Caterpillar 6.25"
Bore Vee Engines Equipped With Hydramechanical Shutoffs

Description of Change: There have been reports of accidental activation of the air shutoffs on 6.25" bore vee engines equipped with hydramechanical shutoffs. This may be caused by pressure spikes in the 5N8963 Actuator Cylinder. The preload in the cylinder is set at 120 kPa (17.5 psi).

There is one air shutoff mechanism on each engine cylinder bank. If only one of the air shutoffs activates, this can eventually damage the cylinder bank whose air shutoff has activated. This occurs if the engine is operated on only one bank for an extended period of time.

A new 2W6314 Actuator Cylinder is used in the 6.25" bore vee engines. It has a preload of 162 kPa (23.5 psi). This increased preload will prevent accidental activation of the air shutoffs.

Caterpillar Information System:

1985/02/11 Addition Of Lubricator Will Help Prevent Corrosion In Air Prelube Motors{1319}

1985/02/11 New Guide Assembly Used In Oil Level Gauge Group{1326,1300}

1985/02/11 Install Crankshaft Thrust Bearings Correctly To Avoid Damage{1202,1203}

1985/02/11 New Flashlight On 6V5000 Infrared Thermometer Group{0776}

1985/02/04 New Temperature Recorders Available{0600}

1985/02/04 Over Fueling Spring No Longer Used In Governor{1264,1250}

1985/02/04 Only The External Needle Valve Can Be Adjusted On Woodward EG3PC Or EG10PC Actuators{1265,1289}

1985/02/04 Tighten Bolts To Correct Torque In 3161 Governor{1264}

1985/02/04 Wiring Harness Conduit Component Sizes{1400,1408}

1985/02/04 Correct Service Information For Air Fuel Ratio Controls Is Available In The Latest Service Manual{1278,1250}

1985/02/04 Use Care When Removing Oil Pan And 9N3167 Plate{1302}

1985/01/28 New Service Tools Available{0600}

1985/02/18 New Pressure Conversion Chart Available{0600}

1985/02/18 New Transmission Control Valve And Pressure Relief Valve Are Used With High Flow Oil Pump{3313,3310}

1985/02/18 Bleed Holes On Parts Service Cylinder Heads{1100,1101}

1985/02/18 New Drive Coupler Kit Used On Altronic Magneto{1552}

1985/02/18 Low Maintenance High Output Batteries Are Now Standard Equipment{1401}

1985/03/04 Use The Correct Oil In Natural Gas Engines{1318,0374}

1985/03/04 3406B Truck Engines Have Been Improved For 1985{1000,1050,1052,1100,1200,1250}

1985/03/04 New Water Cooled Exhaust Manifold Elbows And Rear Manifold Are Used{1059}

1985/03/04 Discontinued D.C. Generators Replaced By Alternators{1404,1405}

1985/03/04 3208 Truck Engine Service Manual Available In Spanish{0375}

1985/03/04 Exhaust Clamp Nut Now Serviced Separately{1061}

1985/03/04 Do Not Weld On Painted Surfaces{0350,0679}