Usage:
D379, D398, D399 Industrial, Marine, And Generator Set Engines;
G379, G398 Natural Gas Engines
Description of Change: New oil pump groups used on the above models have the bypass valve and oil return passage inside the pump. This permits the oil from the bypass valve to flow directly to the pump inlet instead of back to the oil pan. The outside oil lines and bypass valve are no longer used. These changes will prevent possible leakage at outside connections, and decrease the amount of oil which must flow through the pump suction line. This will also decrease aeration (air bubbles) of the oil and cavitation (air) in the pump. The gears, bearings, and shafts in the oil pump are not changed.
Adaptable To: The new pump groups can be installed in place of the former pumps, when the other necessary parts are used. The parts charts show the parts needed for replacement of each former pump. A Special Instruction, Form SMHS7823, is available with complete installation information.
