47-43026T2 Water Pump Impeller & Key for Mercury MerCruiser | JLM Marine

47-43026T2 Water Pump Impeller & Key for Mercury MerCruiser

This high-quality aftermarket water pump impeller with key is designed for Mercury MerCruiser stern drive engines, including the Mercruiser Alpha One Gen 2, and a wide range of Mercury outboard models from 65 HP to 220 HP. Engineered to meet OEM specifications, this impeller ensures reliable cooling system performance across 4-cylinder and 6-cylinder applications.

This impeller directly replaces multiple OEM and aftermarket part numbers, including Mercury MerCruiser 47-43026T2, 47-43026, 8M0025709, CEF Marine 500301, Mallory Marine 9-45037, and Sierra Marine 18-3056. The package includes both the impeller and key (pin) for complete installation.

• Includes rubber impeller with key/pin for immediate installation
• Features 6 blades with precise OEM-spec dimensions for optimal water flow
• Compatible with both stern drive and outboard configurations

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

Your purchase includes:

• Water Pump Impeller (Rubber)
• Impeller Key / Pin

Installation Guide

1. Disconnect the engine and ensure cooling system pressure is fully released before beginning work.
2. Remove the lower unit or access the water pump housing according to your engine's service manual.
3. Disassemble the water pump housing and carefully extract the old impeller. Inspect the housing for debris or damage.
4. Clean all mating surfaces thoroughly, removing old gasket material and corrosion.
5. Lubricate the new impeller blades with glycerin, waterproof grease, or soapy water—never petroleum-based products.
6. Insert the impeller key/pin into the drive shaft slot, ensuring it is fully seated.
7. Install the new impeller by carefully folding the blades in the correct rotation direction as you slide it onto the shaft.
8. Reassemble the pump housing, using new gaskets and O-rings as needed, and torque fasteners to specifications.
9. Reinstall the lower unit or close the pump cover, ensuring all connections are secure.
10. Test the cooling system by running the engine with a flush adapter or in the water, checking for proper water discharge.

Troubleshooting & FAQ

Q: How do I confirm this impeller fits my specific Mercury engine?
A: Cross-reference your engine's serial number range with the compatibility table above. You can also verify the OEM part number on your existing impeller or consult the Mercury parts diagrams linked in the compatibility section.

Q: How often should I replace my water pump impeller?
A: Most manufacturers recommend replacing the impeller every 2–3 years or 200–300 hours of operation, whichever comes first. Inspect it annually and replace immediately if you notice cracked, broken, or missing blades.

Q: What are the signs that my impeller is failing?
A: Common symptoms include engine overheating, reduced or no water flow from the tell-tale (pilot hole), steam from the exhaust, or a high-temperature warning alarm. If you experience any of these, shut down immediately and inspect the impeller.

Q: Can I reuse the impeller key, or must I replace it?
A: We recommend replacing the key each time you change the impeller to ensure proper drive engagement. A worn or damaged key can cause impeller slippage and cooling failure.

Q: Is this an OEM part or an aftermarket replacement?
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.