Johnson Pump 4000 GPH Heavy Duty Bilge Pump (40004)

The Johnson Pump 40004 is a high-capacity, heavy-duty centrifugal bilge pump designed to meet the rigorous demands of commercial vessels and large pleasure boats. Delivering a massive 4000 Gallons Per Hour, this 12V pump is the ultimate solution for primary bilge water removal, emergency dewatering, and high-volume water circulation.

Commercial-Grade Reliability

Engineered for longevity, the 40004 features a high-torque, double-ball-bearing motor and a mechanical seal that eliminates shaft wear and prevents leaks. The pump is designed for continuous duty and features a unique "liquid cooled" motor housing that uses the surrounding bilge water to dissipate heat, significantly extending the life of the motor compared to standard air-cooled models.

Key Features:

• Exceptional Flow Rate: Pumps up to 4000 GPH (252 L/min) at zero head, providing critical safety and rapid water removal in emergency situations.

• Liquid Cooled Motor: The motor is encased in a housing that allows water to circulate around it, preventing overheating during prolonged operation.

• Mechanical Shaft Seal: Features a professional-grade mechanical seal (rather than a simple lip seal) for superior protection against water ingress into the motor.

• Optimized Impeller Design: A high-efficiency, multi-vane impeller maximizes output while minimizing amp draw and vibration.

• Durable Construction: Built with a high-impact ABS plastic body and a corrosion-resistant stainless steel (SS316) shaft.

• Removable Base: Includes a universal strainer base that is easy to remove for cleaning or debris removal without disconnecting the pump from the plumbing.

• Industry Standard Ports: Equipped with a 1-1/2" (38mm) discharge port to handle high-volume flow with minimal resistance.

Technical Specifications:

• Model Number: 40004

• Flow Rate (0ft Head): 4000 GPH (15,140 LPH)

• Voltage: 12V DC

• Amperage: 15.0 Amps

• Fuse Size: 25 Amps

• Discharge Size: 1-1/2" (38mm)

• Max Head: 23 feet (7 meters)

• Weight: 5.4 lbs (2.45 kg)

• Dimensions: 8.5" H x 4.8" W (216mm x 121mm)

Why Choose the Johnson 4000 GPH?

The 40004 is often specified for yachts and commercial fishing boats because of its mechanical seal and ball-bearing motor design.¹⁶ These "pro-level" features make it much more durable for boats that consistently have water in the bilge or those that require a pump capable of running for hours at a time during heavy weather.

Installation Pro-Tip:

To maintain the 4000 GPH flow rate, avoid using corrugated bilge hose, which can reduce performance by up to 30%. Use smooth-bore 1-1/2" reinforced hose and ensure your thru-hull fitting is also a full 1-1/2" diameter.