Sierra 18-3086 Water Pump Impeller, Replaces OMC 379475, 777130

The Sierra 18-3086 is a replacement water pump impeller built for the raw water cooling system of OMC Sterndrive/Cobra I/O units. The impeller is the flexible-vane component inside the sterndrive's water pump housing that draws in raw water and circulates it through the engine's cooling passages; a worn, cracked, or brittle impeller reduces water flow and can lead to engine overheating, so replacing it on a regular service interval or at the first sign of reduced water pressure is standard maintenance for OMC Sterndrive/Cobra owners. This impeller is constructed of aluminum and stainless steel components and is finished in the natural brown rubber commonly used for marine impeller vanes. It is sold as a single impeller unit, packaged one per order, and is a direct cross-reference replacement for OMC part numbers 379475 and 777130, allowing it to be installed in place of the original OMC impeller without modification to the pump housing. Sierra manufactures a range of marine engine parts and this impeller carries a limited warranty. Always confirm the impeller and pump housing match your specific OMC Sterndrive/Cobra water pump before installation.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3086
• Product Type: Impeller
• Material: Aluminum, Stainless Steel
• Color: Brown
• Package Quantity: 1
• Weight: 0.14 pounds
• UPC: 030999315380

Fitment

• I/O - OMC Sterndrive/Cobra cooling system

Replaces (OEM)

• OMC 379475
• OMC 777130

Frequently Asked Questions

What does the Sierra 18-3086 impeller replace? The Sierra 18-3086 is a direct replacement for OMC part numbers 379475 and 777130.

What is the Sierra 18-3086 used for? It is a water pump impeller used in the raw water cooling system of OMC Sterndrive/Cobra I/O units, circulating water through the engine to keep it cool.

How many impellers come in the package? The Sierra 18-3086 ships as a single impeller, packaged one per order.

What material is the Sierra 18-3086 impeller made of? It is made of aluminum and stainless steel components with the brown rubber vane material typical of marine water pump impellers.

How much does the 18-3086 impeller weigh? The Sierra 18-3086 impeller weighs 0.14 pounds.

Is the Sierra 18-3086 an OEM part or aftermarket? Sierra 18-3086 is an aftermarket impeller manufactured by Sierra as a cross-reference equivalent to OMC 379475 and 777130, not an OMC-branded part.

When should I replace the impeller on my OMC Sterndrive/Cobra water pump? Replace the impeller in the OMC Sterndrive/Cobra cooling system when it shows cracking, brittleness, or worn vanes, or if engine cooling water flow decreases, since a degraded impeller like the 18-3086 model reduces raw water circulation and can cause overheating.

Does the Sierra 18-3086 come with a warranty? Yes, the Sierra 18-3086 impeller is covered by Sierra's limited warranty.

What is the UPC for the Sierra 18-3086 impeller? The UPC for the Sierra 18-3086 impeller is 030999315380.

Will the Sierra 18-3086 fit any water pump housing? The 18-3086 is designed specifically for OMC Sterndrive/Cobra I/O cooling system water pumps and should be matched to that pump housing before installation.