1985/12/16 Caterpillar

Later 3406B And 3408B Truck Engines Have Higher Minimum Coolant Temperatures{1350,1355}

Usage:

Reference: October 15, 1984 Service Magazine, Page 6, "New Water Temperature Regulator Has Higher Temperature Setting".

The Reference Article announced that the opening temperature of the 4W4842 Regulator used in 3406B and 3408B Truck Engines was increased from 82°C (180°F) to 88°C (190°F). A higher opening temperature provides a slight increase in fuel economy and better cold weather operation. Field reports indicate some drivers do not know about this increase in opening temperature.

The purpose of any water temperature regulator is to control minimum jacket coolant temperature (engine operating temperature). An engine temperature regulator in proper working condition DOES NOT AFFECT MAXIMUM ENGINE OPERATING TEMPERATURE. Once the temperature regulator is fully opened, the engine operating temperature is determined by other factors, the major ones being ambient temperature, engine load, and cooling system condition and design.

Dash-mounted temperature gauges provide only an approximate temperature of the engine jacket coolant. The temperature must be verified with a more accurate gauge if engine overheating is suspected.

Caterpillar Information System:

1985/12/16 Use Care When Handling Turbocharger Compressor Wheels{1052,1077}

1985/12/16 Troubleshooting Of Jacket Water Heaters{1383}

1985/12/09 New, Tougher Gasket Used Between Block And Front Housing{1151,7555}

1985/12/09 Service Life Of OEM Primary Fuel Filters{1250,1260}

1985/12/09 A Water Separator Can Help Prevent Fuel Injector Damage If Fuel Is Contaminated With Water{1263,1250,1273}

1985/12/09 New Ratchet Wrenches Available For Tube Fittings{0600}

1985/11/25 Oil Pressure Shutdown Specifications Change For Hydramechanical Shutoff System{1085}

1985/11/25 Canister Size Of Coolant Conditioner Element Has Changed{1350}

1985/11/25 Output Shaft Group Improved{3305}

1985/11/25 New Fuel Ratio Control Group Used On Engines Equipped With New Scroll Fuel System{1278}

1985/11/25 Faster Response Water Temperature Regulators; Service Simplified{1350,1355}

1985/11/18 Filter Added To Drain Hole In Water Pumps{1361}

1985/12/16 Gasket Leakage On Aftermarket Fuel Filters{1261}

1985/12/16 Crankshaft Seal Usage On 3400 Series Engines{1160,1161}

1985/12/16 Improved Clutch Disc And Cooling Oil Flow{3300,3302,3303,3306}

1985/12/16 Bushing Kits Available For Crankshaft Pulleys{1205}

1985/12/16 Pressure Gauge Faces With Tonnage Scales Available For Caterpillar Service Tool Manual And Electric Hydraulic Pumps{0615,0616,0799}

1986/01/13 How To Use Temperature And Pressure Probes With Self-Sealing Probe Adapter Groups{0760,0784}

1986/01/13 Fuel Sulfur Analyzer Available{0651,1280,1318}

1986/01/13 Bracket Added To The Watercooled Exhaust Manifold Group To Help Support Turbocharger{1059}

1986/01/13 New Vee Belt Set Used In Fan Drive Group{1357,1359}

1986/01/13 Round Air Cleaner Inlet Adapter Available{1051}

1986/01/13 Lubricate Clamp When Installing Unit Injector Assemblies{1290}

1986/01/13 Put Grease On Front Crankshaft Seal Before Installing The Crankshaft Pulley And Damper{1160}