KIT- 4761065 - Caterpillar

Lower Portion of Nozzle Tip (1).Nozzle Tip at End Of Nozzle Case (2).Terminal Post (3).Solenoid (4).Armature Screw (5).Lower Poppet Seat (6). 1.) Nozzle tip splitting due totip fatigue.2.) Nozzle tip breakage due to side load from improper installation.3.) Solenoid post loosening due to vibration.4.) Solenoid failure due to internal shorting.5.) Armature screw loosening due to manual torque control.6.) Low power complaints due to cavitation erosion of the injector lower poppet seat.
1.) Nozzle tip splitting due to fatigue was observed on some early engines. This failure typically resulted in the tip splitting through an orifice hole and piece of the tip near the end breaking out. This problem was eliminated through several design and process changes which increased the tip wall strength and reduced the check impact at the end of injection. Tip strength has been increased by using a thicker tip wall. Check impact load has been reduced by a design change to increase the check damping and to reduce the check lift.2.) Nozzle tip breakage where the entire shank portion of the tip breaks off near the end of the nozzle case has been seen on some field-replaced injectors. This is a result of side-loading on the tip at injector installation, which occurs when carbon deposits in the tip hole of the injector sleeve are not properly removed. This problem has been addressed by implementing a new plug gauge which is used prior to installing the injector, and ensures that adequate clearance is available at the point of use. In addition, a new cleaning brush was released to facilitate cleaning the hole, instructions were improved, and a special warning wrapper (with international symbols) was affixed to each service injector to alert the installer to the proper procedures. New packaging was also implemented to better protect service injectors during shipping and handling.3.) Solenoid post loosening can occur due to fatigue from prolonged engine vibration. The original containment action to reduce the effect of the vibration was to add a rubber grommet to reduce terminal post movement. The permanent corrective action was to add additional epoxy material to the post. This provides a significant increase in strength and eliminates the need for the rubber grommet.4.) Solenoid failure due to internal shorting was caused by frayed wire insulation from prolonged exposure to engine vibration. This problem was addressed by using wire with a bondable insulation. This new insulation is heat bonded with insulation from adjacent wires forming a single mass that is much stronger and vibration resistant.5.) Armature screw loosening occurred to some injectors due to a manual torquing process used during assembly. This manual process has been eliminated and replaced by a computer controlled automated torquing process. The new automated process assures the correct clamping load on the armature to prevent armature screw loosening.6.) Low power complaints due to cavitation leakage of the injector lower poppet seat has been addressed through new software to reduce actuation pressure during high speed, low fuel delivery conditions. Excessive actuation pressure