2001/08/13 An Improved Unit Injector Hydraulic Pump is Available {1714} Caterpillar

Machine Engines:

3408E

3412E

Description of Change: The unit injector hydraulic pump on these machine engines has been replaced with a new unit injector hydraulic pump. The new unit injector hydraulic pump has increased durability due to the following improvements:

• The new pump barrel is made from heat treated steel instead of powdered metal.

• The diameter of the preload pins has been increased. The preload pins have been moved out of the interface for the splines.

• Relocation of the preload pins allows engagement of three additional splines. This reduces the load per spline.

• The length of the splines has been increased. This reduces the load on the surface of each spline.

• The front lip seal is now made from a Teflon material. The new seal reduces the wear on the shaft. The Teflon material increases the durability of the seal.

Adaptable To: The new 201-4202 Unit Injector Hydraulic Pump Gp is adaptable to all 3408E and 3412E machine engines. The new 201-4202 Unit Injector Hydraulic Pump Gp became effective in production with the following machine engines.

• 3408E (S/N: 99C7190; 5XD389)

• 3412E (S/N: 80M4512; 5JJ264)

The new 201-4202 Unit Injector Hydraulic Pump Gp is a direct replacement for the former 144-0837 Unit Injector Hydraulic Pump Gp. The former 144-0837 Unit Injector Hydraulic Pump Gp has been cancelled. The new 201-4202 Unit Injector Hydraulic Pump Gp does not include the 149-1950 Fuel Transfer Pump .

A new 201-4203 Pump Kit is also available in order to update the former 144-0837 Unit Injector Hydraulic Pump Gp. The new 201-4155 Seal (Front) is included in the pump kit.

A remanufactured 0R-2236 Unit Injector Hydraulic Pump Gp is also available. The previous pumps are acceptable cores for the new remanufactured pump.

Table 1 lists the part numbers for the following components: pump groups, pump kits and pump seals.

Table 1

Former Part	New Part(s)	Additional information
144-0837 Unit Injector Hydraulic Pump Gp	201-4202 Unit Injector Hydraulic Pump Gp	The fuel transfer pump is not included.
144-0835 Unit Injector Hydraulic Pump Gp	201-4202 Unit Injector Hydraulic Pump Gp 149-1950 Fuel Transfer Pump Gp 0S-1617 Bolts (1) 117-1620 Coupling 6V-8676 O-Ring Seal	The fuel transfer pump was included in the former 144-0835 Unit Injector Hydraulic Pump Gp. Now, the fuel transfer pump must be ordered separately along with the parts that mount the fuel transfer pump to the engine. See the "New Part(s)" column in this table.
154-6732 Fuel Injection Pump Kit	201-4203 Pump Kit	This adapts the previous pump to the new design.
165-6881 Seal	201-4155 Seal	This adapts the previous pump to the new design.
0R-9927 Remanufactured Pump	0R-2236 Remanufactured Pump	Previous pumps are acceptable cores.

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Four 0S-1617 Bolts are required.