CONTROL GP-UNPRGMED MONITOR 3657647 - Caterpillar

EnginesSome 0R0715 and 0R2545 Remanufactured Short Blocks may require a new fuel injection pump housing when used in 3406 engines built before 1975.
In 1975, the 4N0812 Fuel Injection Pump Housing Assembly was canceled and replaced by the 6N7276 Fuel Injection Pump Housing Assembly. This change resulted in a larger oil drain passage from the housing to the cylinder block. The cylinder block was also changed to provide a larger oil drain hole.
The 0R0715 and 0R2545 Remanufactured Short Blocks may be built with either a 7N1200 or 8N9265 Block Casting. If the 8N9265 Casting is used, the short block will not work with a 4N0812 Fuel Injection Pump Housing Assembly. This is because the oil drain seal ring used with this housing will not properly seal the oil drain hole in the block. If this situation occurs, the fuel injection pump housing can be changed or a remanufactured short block with the 7N1200 Block Casting may be located.