Water Pump Impeller – Fits Mercury Marine 40-60hp Outboards (Replaces 47-19453T)

Water Pump Impeller – Fits Mercury Marine 40-60hp Outboards (Replaces 47-19453T)

This Sierra 18-8900 water pump impeller is designed for a precise fit on select Mercury, Mariner, and Force outboard engines. It is compatible with most Mercury/Mariner 40-60hp 3-cylinder outboards manufactured from 1991 and later, including both standard and Big Foot models.

This component serves as a direct replacement for several OEM and aftermarket parts, ensuring reliable performance and fitment. It is engineered to meet or exceed original equipment specifications for cooling efficiency and durability.

• Material: High-durability, tear-resistant neoprene rubber
• Installation: Direct replacement for a hassle-free fit
• Includes: One water pump impeller

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 Water Pump Impeller (47-19453T)

Installation Guide

1. Safety First: Disconnect the engine's battery and remove the spark plug wires to prevent accidental starting.
2. Access the Lower Unit: Remove the bolts securing the gearcase (lower unit) to the midsection of the outboard. Carefully lower the unit.
3. Open Water Pump Housing: Locate the water pump assembly on top of the lower unit. Unscrew the bolts to remove the pump cover.
4. Remove Old Impeller: Note the rotational direction of the old impeller blades. Remove the old impeller, key, gaskets, and wear plate.
5. Clean and Inspect: Thoroughly clean the inside of the pump housing and wear plate. Check for scoring or cracks and replace the housing if significant wear is found.
6. Install New Impeller: Place the new wear plate and gasket. Insert the drive key into the shaft and slide the new impeller on, twisting it in the direction of engine rotation to bend the blades correctly.
7. Reassemble Pump: Install the new gasket on the housing and secure the cover with bolts, tightening them to the manufacturer's specified torque.
8. Reinstall Lower Unit: Carefully guide the lower unit back into place, ensuring the water tube and drive shaft align correctly. Secure with bolts.
9. Test Operation: Reconnect the battery and spark plug wires. Start the engine using a water supply (flushing muffs) and confirm a steady stream of water from the tell-tale outlet.

Troubleshooting & FAQ

How do I confirm this impeller fits my Mercury engine?
Verify your engine's model, horsepower, and serial number range against the "Compatible Engine Models" table. For Mercury owners, our linked serial number guide can help you pinpoint the correct model year and specifications before ordering.

What are the signs of a failing water pump impeller?
Common signs include the engine running hotter than normal or overheating, a weak or non-existent water stream from the "tell-tale" outlet, and visible damage like cracks, tears, or stiff, brittle blades on the old impeller upon inspection.

How often should I replace my water pump impeller?
For preventative maintenance, we recommend replacing the impeller every 1-2 years or every 100-200 hours of engine use. Replacement intervals should be shorter for boats used in saltwater or in water with heavy sediment.

OEM vs. Aftermarket?
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.

How fast do you ship and how much does it cost?
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.

What is your warranty and return policy?
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.