Oberdorfer 405M-04-N26 Powerful Self-Priming Performance for Water Transfer, Washdown, and General Utility Pumping
The Oberdorfer 405M-04-N26 pairs a rugged bronze rubber impeller pump with a close-coupled 1 HP, 1725 RPM, 115/230V single-phase motor, giving you a self-contained pumping unit that's ready to install right out of the box. Built from marine-grade bronze with a stainless steel shaft and a neoprene impeller, this pump resists corrosion while moving fresh water, salt water, and other compatible liquids with ease. It's self-priming, capable of pulling a suction lift up to 15 feet once the impeller is wet and the lines are properly sealed, so it gets to work quickly without complicated setup.
What sets this pump apart is its simplicity. With just one moving part inside the pump head, the flexible impeller creates smooth pumping action without the metal-to-metal wear found in gear-driven designs. That means less noise, fewer failure points, and a pump that's genuinely easy to service. The impeller and cam are both simple to access and replace, so routine maintenance never requires swapping out the whole unit. The motor itself is open drip-proof, rated for continuous duty, and includes built-in overload protection, so it holds up to regular, repeated use.
While this pump has long been a go-to for boat bilge, washdown, and baitwell systems, its usefulness doesn't stop at the dock. The same bronze construction and self-priming design make it a solid choice for general industrial transfer, agricultural spraying and irrigation support, wash-down stations, and light chemical-compatible transfer tasks in shops and facilities. Whether you're outfitting a vessel or setting up a transfer station on dry land, the 405M-04-N26 delivers dependable, corrosion-resistant pumping wherever it's needed.
Key Features
- All-bronze pump construction for superior corrosion resistance
- Neoprene rubber flexible impeller with self-lubricating operation
- Stainless steel pump shaft for long-term durability
- Mechanical seal for reliable, drip-free operation
- Self-priming design with up to 15 feet of suction lift
- Single moving part inside the pump head for simplified maintenance
- Close-coupled 1 HP electric motor, no separate coupling required
- Open drip-proof (ODP) motor rated for continuous duty
- Built-in motor overload protection
- Bi-directional operation; flow direction follows shaft rotation
Applications
- Marine bilge, washdown, and baitwell transfer
- Fresh water and salt water transfer
- General industrial liquid transfer
- Agricultural spraying and irrigation support
- Wash-down stations and facility maintenance use
- Mild chemical-compatible liquid transfer (non-solvent, non-fuel)
- OEM and replacement pump applications
Specifications
- Part Number: 405M-04-N26
- Pump Type: Close-coupled rubber (flexible) impeller pump and motor
- Pump Body Material: Bronze
- Impeller Material: Neoprene rubber
- Shaft Material: Stainless steel
- Seal Type: Mechanical seal
- Motor Horsepower: 1 HP
- Motor Speed: 1725 RPM
- Voltage: 115/230V
- Phase: Single phase
- Motor Enclosure: Open Drip-Proof (ODP)
- Inlet Port: 1 inch NPT / 1-1/2 inch hose
- Discharge Port: 1 inch NPT / 1-1/2 inch hose
- Maximum Suction Lift: 15 feet (when primed)
- Operating Temperature Range: 45°F to 180°F (7°C to 82°C)
Frequently Asked Questions
Q: Does this pump need to be primed before use?
Yes. Like all flexible impeller pumps, the 405M-04-N26 must be primed before startup so the impeller is never allowed to run dry. Running it dry, even briefly, will damage the impeller blades and shorten its service life.
Q: Can this pump run in either direction?
Yes. It can operate in either rotational direction, and the direction of shaft rotation determines which port serves as inlet and which serves as discharge. It's best to manually rotate the pump in the desired direction before first installation to set the impeller blades.
Q: What should I do if I'm storing the pump for an extended period or expecting freezing temperatures?
Drain the pump chamber by removing the drain plug, and if freezing is a concern, fill the chamber with a methyl alcohol-based antifreeze. For long-term storage, it also helps to remove the impeller so the blades don't take a permanent set.
Q: How do I know when the impeller needs to be replaced?
A worn or damaged impeller typically shows up as reduced pumping pressure or noticeably lower flow. The impeller is accessible by removing the cover screws and can be pulled out and replaced without disassembling the rest of the pump.
Q: Can this pump handle liquids other than water?
It's designed primarily for fresh water, salt water, and mild, non-corrosive chemical solutions compatible with a neoprene impeller. It should not be used with gasoline, strong solvents, or acids, since these will degrade the impeller material.
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