Oberdorfer 406M-04 Bronze Macerator Pump End — Reliable Sewage Transfer and Utility Pumping Built to Last
The Oberdorfer 406M-04 is a pump end only — meaning it mounts directly onto a separately sourced NEMA C-flange motor, giving you the flexibility to pair it with the drive that fits your setup. The pump body is cast from durable bronze, and the shaft is stainless steel, making this unit genuinely tough in environments where moisture, waste, and corrosive conditions are the norm. The neoprene rubber impeller provides positive displacement pumping action and handles up to 21 GPM, with a self-priming capability and suction lift of up to 15 feet when the pump is fully primed and plumbing is air-tight. A Buna-N impeller is available as an option for applications involving mild oil contamination or chemicals compatible with that material.
What makes the 406M-04 useful across a wide range of industries is its versatility. It isn't limited to any single type of installation — it works well for sewage transfer at campsites, holding tank pumpout for trailers and mobile homes, dockside waste removal, general utility transfer, and emergency liquid handling. The integrated macerator breaks down solids in the liquid stream, which reduces the risk of clogging and extends the service life of downstream plumbing. The wear plate inside is both reversible and replaceable, so you're not looking at a full pump replacement when components wear down. With an optional vacuum switch shut-off available, the system can also protect itself from running dry — a common cause of impeller failure in flexible impeller pump designs.
Key Features
- Pump end only — mounts to a separately sourced NEMA C-flange motor (motor not included)
- Cast bronze housing for corrosion resistance in wet and waste environments
- Stainless steel shaft for durability and long service life
- Standard neoprene rubber impeller; Buna-N (nitrile) impeller available on request
- Integrated replaceable macerator for handling solids in the liquid stream
- Mechanical seal (carbon/ceramic/Buna-N) — no packing required
- Reversible and replaceable wear plate for extended serviceability
- Self-priming design — suction lift up to 15 feet when fully primed
- Configurable for either rotational direction at setup (uni-directional once set)
- Optional vacuum switch shut-off to prevent dry-run damage
- Machined-in cam for improved impeller performance and longevity
- Easy impeller access for routine maintenance
Applications
- Sewage transfer at residential, commercial, and portable facilities
- Holding tank pumpout for campers, campsites, trailers, and mobile homes
- Dockside waste pumpout stations
- General utility liquid transfer
- Emergency pumping situations
- Fresh and salt water transfer
- Mild chemical solutions compatible with neoprene or Buna-N impeller materials
Specifications
- Part Number: 406M-04
- Construction: Cast bronze body, stainless steel shaft
- Impeller Material: Neoprene rubber (standard); Buna-N optional
- Seal Type: Mechanical — carbon/ceramic/Buna-N
- Flow Rate: 21 GPM
- Maximum Suction Lift: 15 feet (when fully primed)
- Temperature Range: 45°F to 180°F (7°C to 82°C) — neoprene impeller; 40°F to 140°F recommended operating range
- Inlet Port: 1-1/2" Male NPT with 2" OD barb for 2" ID hose
- Outlet Port: 1" Female NPT with OD barb for 1-1/2" ID hose
- Drive Coupling: Close-coupled to NEMA C-flange motor
- Motor: Not included
- Macerator: Integrated, replaceable
- Vacuum Switch Shut-off: Optional
- Fluids Handled: Fresh water, salt water, water solutions, mild chemicals (no gasoline, solvents, or acids)
Frequently Asked Questions
Q: Does the Oberdorfer 406M-04 come with a motor?
No. The 406M-04 is a pump end only. It is designed to be close-coupled to a separately sourced NEMA C-flange motor. If you need a complete pump and motor unit, Oberdorfer offers assembled models such as the 406M-04N26, which includes a 1 HP, 1725 RPM, single-phase AC motor.
Q: Can this pump handle solids or waste material in the liquid stream?
Yes. The 406M-04 features an integrated replaceable macerator that breaks down solids present in the pumped liquid. This makes it appropriate for sewage transfer and holding tank pumpout applications where solid waste content is expected.
Q: Is the pump reversible — can it run in both directions during operation?
The pump can be configured for either rotational direction at initial setup, but once that configuration is set, it becomes a uni-directional pump. Because of the macerator feature, it cannot alternate between both directions during normal operation.
Q: What liquids should never be pumped with the 406M-04?
Gasoline, severe solvents, and acids must never be pumped with this unit. The standard neoprene impeller is not compatible with these substances. Nitrile (Buna-N) impellers can tolerate mild oil-contaminated water and kerosene, but with a reduced service life. When in doubt, flush the pump with fresh water after each use.
Q: What maintenance should I expect with normal use?
The wear plate inside the pump is both reversible and replaceable, which extends the service interval before a full replacement is needed. The impeller is also user-replaceable. When the unit will not be in use for extended periods, drain the pump body using the provided drain plug and consider filling the chamber with a methyl alcohol-based antifreeze compound to prevent freeze damage.
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