Sierra 18-3001 Impeller, Replaces OMC 277181 and 434424

The Sierra 18-3001 is a water pump impeller designed as a direct replacement for outboard cooling systems that originally used OMC 277181 or OMC 434424 impellers. The impeller is the core wear component inside a marine water pump housing: as it rotates, its flexible vanes draw raw water through the intake and push it through the engine's cooling passages to keep the powerhead running at a safe temperature. Because impeller vanes lose flexibility and can crack or shed material over time, especially after dry-running or extended storage, replacing this part on schedule is one of the most important preventive maintenance steps an outboard owner can perform. Neglecting a worn impeller is a common cause of overheating and expensive powerhead damage. The Sierra 18-3001 is sized and configured to install as a like-for-like swap for the original 277181/434424 impeller, so it drops into the existing water pump housing without modification. It ships as a single impeller unit, ready to be installed during a routine water pump service or full water pump rebuild. Keeping a spare on board or in the shop is inexpensive insurance against a cooling system failure on the water.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3001
• Product Type: Water Pump Impeller
• Package Dimensions: 6.81 inches L x 5.98 inches W x 0.55 inches H
• Weight: 0.09 pounds
• Package Quantity: 1
• UPC: 030999237118
• GTIN: 00030999237118
• Included Components: Impeller
• Warranty: Limited Warranty

Fitment

Fits applications originally equipped with OMC impeller 277181 or 434424.

Replaces (OEM)

• 277181
• 434424

Frequently Asked Questions

What does the Sierra 18-3001 impeller replace? The Sierra 18-3001 is a direct replacement for OMC impeller numbers 277181 and 434424, so any application originally built around either of those part numbers accepts the 18-3001 as a drop-in swap.

Is the Sierra 18-3001 an OEM part or an aftermarket equivalent? It is an aftermarket impeller manufactured to match the fit and function of the original OMC 277181 and 434424 impellers, sold under the Sierra part number 18-3001.

How many impellers come in one order of part number 18-3001? One order includes a single impeller; the package quantity for the 18-3001 is 1 unit.

What are the package dimensions of the 18-3001 impeller? The packaged 18-3001 measures 6.81 inches long by 5.98 inches wide by 0.55 inches high.

How much does the Sierra 18-3001 impeller weigh? The 18-3001 impeller weighs 0.09 pounds.

When should the 18-3001 impeller be replaced? Impellers like the 18-3001 should be replaced as part of routine water pump maintenance, since the rubber vanes lose flexibility and can crack over time, particularly after dry-running or long storage periods; a worn impeller is a leading cause of engine overheating.

What is included when I purchase the 18-3001? The 18-3001 ships as the impeller component only, ready to install into the existing water pump housing.

Does the 18-3001 impeller come with a warranty? Yes, the Sierra 18-3001 impeller is covered by a limited warranty.

Can I use the 18-3001 impeller for a full water pump rebuild? Yes, the 18-3001 is commonly installed during a water pump service or rebuild wherever the original impeller carried OMC part number 277181 or 434424.

What is the UPC for the Sierra 18-3001 impeller? The Sierra 18-3001 impeller carries UPC 030999237118 and GTIN 00030999237118.