Sierra 18-3389 Water Pump Kit with Housing - Replaces 436957, 0438591, 0432955

The Sierra 18-3389 Water Pump Kit with Housing is a complete replacement water pump assembly built to restore proper cooling flow on outboard engines using the original equipment configuration matching part numbers 436957, 0438591, and 0432955. The kit includes the water pump housing along with the internal components needed to complete the rebuild, including a Sierra 18-7481 O-Ring (O.E. 324981) and a Sierra 18-2703 Grommet (O.E. 314008), so the job can be finished without hunting down separate small parts. Reliable cooling pump function is critical to outboard engine health, since a worn or failing water pump can lead to inadequate raw water flow and overheating. This kit is designed as a direct equivalent to the original equipment part it replaces, matching fit and function so it can be installed using the same procedure as the OEM housing it is replacing. The kit weighs 1.21 pounds as packaged. Buyers replacing a worn or leaking water pump housing on their outboard can use this kit as a single-source solution covering the housing and the associated O-ring and grommet needed for a proper seal.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3389
• Product Type: Water Pump Kit with Housing
• Weight: 1.21 pounds
• Kit Includes: O-Ring (Sierra 18-7481, O.E. 324981), Grommet (Sierra 18-2703, O.E. 314008)
• OEM Cross Reference: 436957, 0438591, 0432955

Replaces (OEM)

• 436957
• 0438591
• 0432955

Frequently Asked Questions

What does the Sierra 18-3389 Water Pump Kit include? The kit includes the water pump housing along with a Sierra 18-7481 O-Ring (O.E. 324981) and a Sierra 18-2703 Grommet (O.E. 314008), giving you the housing and the small parts needed to complete the rebuild in one kit.

Which OEM part numbers does the 18-3389 replace? This kit replaces OEM part numbers 436957, 0438591, and 0432955.

How much does the Sierra 18-3389 Water Pump Kit weigh? It weighs 1.21 pounds as packaged.

Does this kit come with a housing or just internal parts? Yes, the Sierra 18-3389 is a full kit that includes the water pump housing itself, not just the internal seal components.

Is the Sierra 18-3389 a genuine OEM part or an aftermarket equivalent? It is a Sierra-manufactured aftermarket kit designed to be a direct equivalent to the original equipment part it replaces, matching the original part numbers 436957, 0438591, and 0432955.

What is the O-Ring part number included in this kit? The included O-ring is Sierra part 18-7481, corresponding to O.E. Number 324981.

What is the Grommet part number included in this kit? The included grommet is Sierra part 18-2703, corresponding to O.E. Number 314008.

Can I use the 18-3389 kit to rebuild a water pump instead of buying individual parts? Yes, since the kit bundles the housing, O-ring, and grommet together, it covers the parts most commonly needed for a water pump rebuild in a single purchase.

Why would my outboard need this water pump kit replaced? A worn or leaking water pump housing can reduce raw water flow to the engine, so replacing it with the Sierra 18-3389 kit helps restore proper cooling.

Is the Sierra 18-3389 kit a direct fit replacement? Yes, it is built to match the fit and function of the original equipment part carrying numbers 436957, 0438591, and 0432955, so it installs the same way as the part it replaces.