Sierra Impeller 18-3087 for MerCruiser Bravo and Inboard Water Pumps, Replaces Mercury Marine 47-59362

The Sierra 18-3087 is a water pump impeller built for MerCruiser Bravo drives and inboard engines that use a plastic water pump body, covering units from serial number 3040411 and above. It is also referenced for MerCruiser engines with engine-mounted sea water pumps, 1999 and older. The impeller is the wear component inside the raw water pump that draws in and circulates outside water to cool the engine; as its blades flex and wear over time and pump temperature rises, cooling efficiency drops and the risk of overheating increases, so periodic replacement is standard maintenance for any engine-mounted marine cooling system.

Constructed of a rubber or plastic material in a black finish, the 18-3087 is engineered as a direct fit for the plastic-body Bravo and inboard water pump housings it is listed for, and it carries the Mercury Marine 47-59362 and 47-59362T1 cross-reference numbers so it can be ordered as a like-for-like replacement in existing pump assemblies. Each unit ships as a single impeller for one water pump. Sierra parts are backed by the manufacturer's standard customer satisfaction warranty, giving boat owners and marine technicians a dependable option when servicing MerCruiser raw water cooling systems.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-3087
• Product Type: Impeller
• Weight: 0.43 pounds
• Material: Rubber or Plastic
• Color: Black
• Mounting Type: Engine Mount
• Recommended Use: For Fresh Water
• Quantity: 1 impeller per unit
• UPC: 030999315397
• OEM Cross Reference: 47-59362, 47-59362T1

Fitment

• MerCruiser Bravo drives and inboard engines with plastic water pump body, serial number 3040411 and above
• MerCruiser engines with engine-mounted sea water pumps, 1999 and older

Replaces (OEM)

• Mercury Marine 47-59362
• Mercury Marine 47-59362T1

Frequently Asked Questions

What engines does the Sierra 18-3087 impeller fit? The Sierra 18-3087 is built for MerCruiser Bravo drives and inboard engines with a plastic water pump body, serial number 3040411 and above, and it is also referenced for MerCruiser engines with engine-mounted sea water pumps, 1999 and older.

Is the 18-3087 a direct replacement for a Mercury Marine impeller? Yes, part number 18-3087 cross-references to Mercury Marine 47-59362 and 47-59362T1, so it installs as a like-for-like replacement in those pump assemblies.

What OEM part numbers does 18-3087 replace? The 18-3087 impeller replaces Mercury Marine 47-59362 and 47-59362T1.

What material is the 18-3087 impeller made from? It is made of a rubber or plastic material in a black finish, sized for the plastic-body water pump housings it is designed to fit.

How much does the 18-3087 impeller weigh? The Sierra 18-3087 impeller weighs 0.43 pounds.

How many impellers come in one 18-3087 package? Each 18-3087 package contains one impeller for a single water pump.

Will the 18-3087 fit a water pump with a brass body? No, the 18-3087 is designated for MerCruiser Bravo and inboard water pumps with a plastic pump body; brass-body pumps use a different Sierra part number.

Is the 18-3087 a genuine Sierra part or a generic aftermarket copy? It is a genuine Sierra-branded impeller, sold under Sierra's own part number 18-3087 with Sierra's standard customer satisfaction warranty.

What is the recommended use for the 18-3087 impeller? The 18-3087 is recommended for use in fresh water applications within its listed MerCruiser water pump fitment.

Does the 18-3087 come with installation gaskets? The 18-3087 listing covers the impeller only; the water pump housing gaskets used in the same MerCruiser cooling system service are separate parts.

How do I know if my MerCruiser needs impeller 18-3087 versus a different Sierra impeller? Match your MerCruiser water pump body type and serial number to the Bravo/inboard plastic-body pump range covered by 18-3087; units with a brass pump body or a different serial range use a different Sierra part number.