To identify an Attwood bilge pump, start with the old unit's voltage marking and outlet diameter. A Sahara Mk2 pump has an integrated automatic float, whereas an HD-series pump uses separate electrical control. A float switch and a hand pump are different pieces of equipment. Use the model comparisons below before substituting a similar-looking unit.
Identify the pump's operating system
Simplified identification illustrations, not installation or wiring diagrams.
How to narrow down an unknown bilge pump
- Photograph the old label and wiring before removing the damaged assembly, with power disconnected.
- Check the hose barb: HD models shown use 1-1/8-inch hose, but Sahara Mk2 options differ by model.
- Inspect for an integrated float or a nearby separate float switch. Confirm the bilge's working water level.
- Compare 12V and 24V labels and the pump's required fuse and wiring configuration.
- Use the exact MPN and product photo to compare the replacement's base and outlet position before ordering.
Compare the Attwood identification numbers
| MPN | Series / type | Power | Control | Outlet or hose |
|---|---|---|---|---|
| 4730-4 | HD1700 | 12V DC | Electric; external control | 1-1/8 in |
| 4760-4 | HD2000 | 12V DC | Electric; external control | 1-1/8 in |
| 5508-7 | Sahara Mk2 S800 | 12V DC | Automatic; integrated float | 3/4 or 1 in barb |
| 5513-7 | Sahara Mk2 S1200 | 24V DC | Automatic; integrated float | 1 or 1-1/8 in barb |
| 4201-7 | Automatic float switch | 12V or 24V DC | Separate switch; not a pump | No hose outlet |
| 11596-2 | Hand-operated bilge pump | Not electric | Manual; no wiring | Supplied 32-in hose |
Two similar model names may require different voltage and hose sizes. The separate switch has no discharge port; the hand pump is not an electric bilge assembly.
Review the matching Attwood components
Use the images and manufacturer numbers to identify the part. Review each store listing for its condition and availability.
Identify a separate-control heavy-duty pump
The HD1700 and HD2000 names identify two separate powered models. If a float switch was installed nearby, it is not included in the pump housing.
Check the integrated-float Sahara Mk2 family
Both examples incorporate float switching but are not electrically interchangeable. Check the manufacturer's part label and outlet choice.
Identify the separate switch and cover
The covered float switch is separate from the pump. Its model number, cable, and rating matter when replacing it.
Recognize the non-electric hand pump
A manual tube-style pump does not share fittings, voltage or control wiring with permanently mounted models.
For model specifications and discharge-flow guidance, consult the Attwood manufacturer product catalog. A bilge pump is intended to remove normal accumulated water, not to compensate for hull damage or unsafe navigation.
See each UsedRVParts listing for condition and availability. Viewing and pickup in Kelowna are by appointment.