1994/08/30 Caterpillar

Changing Complete Sets Of Fuel Injection Pump Groups May Not Fix Low Power Problems{1251}

Usage:

3406C (4CK24722-UP, 3ZJ51745-UP) Truck Engines

An Improved 108-6634 Fuel Injection Pump Group is used in the above truck engines. Previous 3406B and 3406C Engines had a different bonnet-to-barrel seal design.

In some instances, complete sets of fuel injection pump groups were changed in an attempt to fix low power complaints. In some cases on previous engines, changing all six fuel injection pump groups was successful. However, the new bonnet-to-barrel seal design is not a common cause of low power complaints.

When troubleshooting low power or other performance complaints on the above engines, and an injection pump is believed to be the cause of the problem, change only those fuel injection pump groups that are suspect. Do Not change the complete set.

Caterpillar Information System:

1994/08/30 New Water Seals Used in 3400 Head Assemblies{1124}

1994/08/30 New Exhaust Manifolds, Longer Mounting Studs And Spacers Used In Exhaust Manifold Groups{1059}

1994/08/30 Longer Studs And Spacers Used To Retain Exhaust Manifolds{1059}

1994/08/30 False Logging Of Diagnostic Codes 100-01 (FC46) "Low Oil Pressure" And 100-11 (FC46) "Very Low Oil Pressure"{1902}

1994/08/30 New Oil Pressure Regulating Valve Used In Oil Filter Group{1315}

1994/08/30 New 310A Jake Brake® Available{1119}

1994/08/30 December 1993 FLASH File Update And Fan Control Logic{1902}

1994/08/30 Service Procedure For 40 Pin Connector Seal{1901}

1994/08/30 Use Of 4C-4377 Stress Plate Group In 3116 Cylinder Block Reconditioning{0672,0673,1201}

1994/08/30 Changes To 3116 Truck Engine For 1994{0374}

1994/07/01 Fuel Injection Nozzle Spray Orifice Plugging{1254}

1994/07/01 Be Sure To Use The Correct Reverse Flow Check Valve{1251}

1994/08/30 Use Only Clean Engine Oil To Lubricate Unit Injector O-Rings{1290}

1994/09/01 Caterpillar Introduces New Long Life Heavy Duty Engine Coolant{1395}

1994/09/01 New Fuel Priming Pump And Gasket Used{1258}

1994/09/01 New Fuel Priming Pump Assembly Used In Fuel Priming Pump Group{1258}

1994/09/01 Improved Fuel Pump Bonnet Seal Has Better Heat Resistance{1251}

1994/09/01 Remanufactured 3400 Cylinder Heads Now Use Intake And Exhaust Valves With Chrome Plated Valve Stems{1105}

1994/09/01 Turbocharger Popping Noise Does Not Cause Damage{1052}

1994/09/01 Additional Parts Now Provided With 0R-4180 Remanufactured Cylinder Head Assembly{1100}

1994/09/01 New Seals In Pump Fastener Group And Fuel Injection Pump Group Have Improved Heat Set Resistance{1251}

1994/09/01 Impeller Appearance On Remanufactured 3406 Water Pump{1364,1361}

1994/09/01 New Gasket Provides Improved Sealing Between Air Compressor And Drive{1803}

1994/09/01 117-7213 Control Group (Vehicle Speed Filter) Available For Field Installation{1914}