FUEL PUMP HOUSING ASSEMBLY 4P9840 - Caterpillar

Probable Causes
Circuit breakers
Battery cables
Batteries
Starting circuit
Flywheel ring gear
Driven equipment
Engine accessories
Hydraulic cylinder lock
Internal engine problemRecommended Actions
Circuit Breakers
Check the state of each of the circuit breakers. Reset the circuit breakers if the circuit breakers are tripped. Prior to returning the engine to service, determine the condition that caused the circuit breaker to trip. Make the necessary repairs.Battery Cables and/or Batteries
Inspect the battery disconnect switch, bus bars, battery posts, and battery cables for loose connections and corrosion. If the battery cables are corroded, remove the battery cables and clean the battery cables. Tighten any loose connections.
Inspect the batteries.
Charge the batteries. Refer to Special Instruction, SEHS7633, "Battery Test Procedure".
Load test the batteries. Refer to Special Instruction, SEHS9249, "Use of 4C-4911 Battery Load Tester for 6, 8 and 12 Volt Lead Acid Batteries".Starting Circuit
Test the operation of the starting motor and associated circuit components. Refer to the Systems Operation/Testing and Adjusting manual.Driven Equipment and/or Engine Accessories
Ensure free movement of the driveline.
Ensure that the timing pin was not left in the flywheel housing.
Remove any engine accessories that may lock up the engine. Inspect the condition of the accessories.The following list illustrates examples of engine accessories that may lock up the engine:
Fuel transfer pump
Air compressor
Engine oil pump
Engine shutdown switches
Start interlock
Prelubrication system
Crank enable switchHydraulic Cylinder Lock
Check for fluid in the cylinders (hydraulic cylinder lock) by removing the individual unit injectors.Note: Be sure to drain the fuel from the cylinder head prior to removing the injectors. Fuel will flow from the cylinder head into the cylinders when the unit injector is removed.Internal Engine Problem
Inspect the internal components for the following conditions:
Seizure
Broken components
Bent components