1994/07/01 Caterpillar

Be Sure To Use The Correct Reverse Flow Check Valve{1251}

Usage:

3406C (3ZJ, 4CK) Truck Engines

The 4P-9258 Reverse Flow Check Valve is the only check valve authorized for use in the following engines:

3406C (4CK12169 - Up) Truck Engines.

3406C (3ZJ34764 - Up) Truck Engines rated at 425 HP.

3406C (3ZJ35460 - Up) Truck Engines (All ratings other than 425 HP.)

Complete sets of 4P-9258 Reverse Flow Check Valves are being replaced and analysis of the returned valves shows there is nothing wrong with the check valves. The most common engine symptom identified with the returned check valves is "low power". Most true "low power" problems are fixed by identifying other engine or fuel system root causes and not by changing check valves.

Investigation indicates complete sets of 4P-7688 Reverse Flow Check Valves are being used to replace 4P-9258 Reverse Flow Check Valves. The use of the 4P-7688 Reverse Flow Check Valve as a replacement for the 4P-9258 Reverse Flow Check Valve is NOT an authorized repair, because it is not an EPA emissions approved fuel system change.

Caterpillar Information System:

1994/06/24 Installation Procedure For 1R-0716 Engine Oil Filter{1318}

1994/06/24 Procedure For Lapping Sealing Surfaces Of Fuel Injection Pump Barrels And Bonnets{1251}

1994/06/24 New Valve Lifter Assembly Provide Improved Lubrication Of Lifter Roller And Camshaft Lobes{1209,1210}

1994/06/24 New Rocker Arm Adjustment Screw Used To Adjust Valve Clearance{1123,1100}

1994/06/24 New Intake And Exhaust Valves Used{1105,1100}

1994/05/31 New Oil Cooler And Filter Base Assembly And New Oil Cooler And Filter Base Group Have Stronger Mounting Flanges {1378,1306}

1994/05/31 Date Code On 7000 Series Fuel Injection Nozzles; New Seals Used In 7000 Series Fuel Injection Nozzles {1254}

1994/04/22 Service Tools For Electronic Controls{0781,0782}

1994/04/22 Final Control Group (Personality Module) Update{1902}

1994/04/22 Fuel Injection Pump Improvements{1251}

1994/04/22 Identification Of Intake And Exhaust Valves That May Be Used In Remanufactured Direct Injected 3400 Cylinder Heads{1105}

1994/04/22 New Air Compressor Drive Gear Used In Accessory Drive Group{1207}

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

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

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

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

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

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

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

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 Longer Studs And Spacers Used To Retain Exhaust Manifolds{1059}

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

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

1994/08/30 Changing Complete Sets Of Fuel Injection Pump Groups May Not Fix Low Power Problems{1251}