Johnson Pump 40004 Heavy Duty 4000GPH 12V Bilge Pump The Johnson Pump Heavy Duty Bilge Pumps are designed to exceed commercial and recreational demands. Featuring a 12-pole motor with double ball bearings for an extended service life. The impeller is designed to maximize flow and head. A universal base plate allows for a choice between two different ports and easy installation. The 4000 GPH model features a durable motor design with a mechanical shaft seal, high impact ABS plastic a unique thre