Usage:
G3406 (4FD1588-Up, 1RK87-Up) Engines
Description of Change: A new pump group that includes a cast iron impeller has replaced the former axial screw type pump group in the auxiliary fresh water pump group used in the SCAC cooling system on these engines. The new pump group will flow less coolant than the former pump group given the same amount of external resistance. Before changing from the former to the new pump group, review the pump curve chart to assure sufficient coolant flow for proper heat rejection (see the included Chart A). A new SCAC lines group is used to connect the outlet of the new pump group to the inlet of the aftercooler.
Adaptable To: The new components in the 146-6771 Auxiliary (Fresh Water) Pump Group are identified in Illustration 1 and Chart B.
The new 146-6784 Water Lines Group (SCAC) is required with the new 146-6771 Auxiliary (Fresh Water) Pump Group. The only difference between the new 146-6771 Auxiliary (Fresh Water) Pump Group and the 7C-1048 Water Lines Group (SCAC) used with the former 3N-4851 Auxiliary (Fresh Water) Pump Group is the tube that connects the pump outlet to the aftercooler inlet. Illustration 2 and Chart C identify the new tube and other components required to make the change.
Illustration 3 and Chart D identify the serviceable components of the new 144-8828 Auxiliary (Fresh Water) Pump Group.
Illustration 1.
Identification of new components in the 146-6771 Auxiliary (Fresh Water) Pump Group.
Chart A. (PUMP PERFORMANCE)
Illustration 2.
Identification of components in the new 146-6784 Water Lines Group (SCAC).
Illustration 3.
Identification of serviceable components in the new 144-8828 Auxiliary (Fresh Water) Pump Group.
