Sea Water Pump Impeller with O-Rings – Fits MerCruiser Bravo I, II, III Stern Drives (Replaces 47-59362T1, Sierra 18-3087)

Sea Water Pump Impeller with O-Rings – Fits MerCruiser Bravo I, II, III Stern Drives

This sea water pump impeller is a direct-fit replacement for MerCruiser Bravo I, II, and III stern drives, as well as MerCruiser inboards that use a sea water pump with a "D" shaped impeller hub. It is compatible with 4.3L, 5.0L, 5.7L, 7.4L, and 8.2L V8 GM series engines from 1999 and newer.

This kit provides a direct replacement for multiple OEM and aftermarket part numbers, ensuring a precise fit for your engine's raw water pump. Note: This impeller fits pumps with plastic housings and will NOT fit newer Bravo drives with brass housings (including the 8.1L 496 engine) which use an impeller with 2 flat sides on the shaft.

• Includes one neoprene impeller and two O-rings for a complete installation.
• Engineered with a "D" shaped hub for specific engine-mounted sea water pumps.
• Designed for a direct-fit installation, replacing the original impeller without modification.

Part Number Cross-Reference

Use this table to confirm equivalent part numbers across OEM and aftermarket brands.

Compatible Engine Models

Confirm your engine model/year in the table below. For Mercury owners, here’s a guide to help you identify your engine’s serial/model: Mercury Serial Number Guide. You can also review exploded diagrams to verify part numbers: Mercury Parts Diagrams & Catalog.

Technical Specifications

Package Contents

• 1 x Impeller (replaces 47-59362T1)
• 1 x O-Ring (replaces 25-33465)
• 1 x O-Ring (replaces 25-94288)

Installation Guide

1. Safety First: Disconnect the boat's battery before starting any work.
2. Access the Pump: Locate the sea water pump on the front of the engine. You may need to remove the serpentine belt and/or other components to access it.
3. Remove the Pump Housing: Unscrew the bolts holding the plastic pump housing cover in place.
4. Extract the Old Impeller: Carefully remove the old impeller from the housing. Impeller puller pliers can make this easier. Note the direction of the blades if they are still intact.
5. Clean the Housing: Inspect the housing for cracks, scoring, or debris. Clean it thoroughly.
6. Install the New Impeller: Lightly lubricate the inside of the housing and the new impeller with a marine-safe lubricant (like dish soap). Insert the new impeller, twisting it in the direction of engine rotation to bend the blades correctly.
7. Replace O-Rings: Remove the old O-rings and install the new ones provided in the kit. Ensure they are seated correctly.
8. Reassemble the Pump: Reattach the pump housing cover and tighten the bolts to the manufacturer's specified torque.
9. Reinstall Components: Reinstall the serpentine belt and any other components you removed.
10. Test the System: Reconnect the battery. Start the engine with a proper water supply and check for leaks and proper water flow from the exhaust.

Troubleshooting & FAQ

Q: How can I be sure this impeller fits my MerCruiser Bravo engine?
A: This impeller is designed for MerCruiser Bravo I, II, and III models from 1999 and up using specific V8 engines (4.3L, 5.0L, 5.7L, 7.4L, 8.2L). The most critical check is the pump design: this impeller fits pumps with a plastic housing and a "D" shaped hub (one flat side on the shaft). It will not fit newer Bravo drives with a brass pump housing or those requiring a double-flat-sided ("keyway") impeller, such as on the 8.1L 496 engine.

Q: What are the signs of a failing water pump impeller?
A: Common signs include the engine overheating at idle or low speeds, a reduced stream of water from the exhaust, or visible cracks and missing blades on the impeller itself during inspection. A damaged impeller can lead to severe engine damage if not replaced.

Q: How often should I replace my sea water pump impeller?
A: As a general rule, it is recommended to inspect your impeller annually and replace it every 1-2 years or every 100-200 hours of operation, whichever comes first. This interval can be shorter if you operate in sandy, silty, or saltwater environments.

Q: OEM vs. Aftermarket?
A: This listing is an aftermarket replacement part (not an OEM component). We build to OEM specifications using comparable-grade materials. Production is done in an ISO9002-certified facility, and each batch is inspected for consistent performance.

Q: How fast do you ship and how much does it cost?
A: We offer fast global shipping—typically 5–15 days worldwide—and standard shipping is free. Expedited options are available at checkout depending on your location.

Q: What is your warranty and return policy?
A: This product includes a 1-year warranty against manufacturing defects under normal use. If something goes wrong, contact our support team with your order details. Returns are accepted within our standard return window (unused & in original condition); please see our policy page or reach out for instructions.

Important Notes

• Verify that the product images and specifications match your original part. If discrepancies exist—even if your model is listed—do not proceed with the purchase.
• This product is an aftermarket replacement part and is not an OEM component.
• Professional installation is recommended to ensure safety and optimal performance.

Why Choose JLM MARINE?

• Quality Assured: As a trusted manufacturer for over 20 years, we supply top marine brands globally.
• Fast Global Shipping: Free delivery worldwide in 5–15 days.
• Direct from Manufacturer: Competitive pricing without compromising quality.