Water Pump Kit – Fits Mercury/Mercruiser Engines (Replaces 879031)

$46.76

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You may return most new, unopened items within 7 days of delivery for a full refund. We'll also pay the return shipping costs if the return is a result of our error (you received an incorrect or defective item, etc.).

You should expect to receive your refund within four weeks of giving your package to the return shipper, however, in many cases you will receive a refund more quickly. This time period includes the transit time for us to receive your return from the shipper (5 to 10 business days), the time it takes us to process your return once we receive it (3 to 5 business days), and the time it takes your bank to process our refund request (5 to 10 business days).

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Delivery and Shipping

Free standard shipping on all orders under 1 KG

If you have any questions, feel free to email us at info@sierramarines.com, and we’ll get back to you within 20–36 hours.

Product Details

This aftermarket Water Pump Kit – Fits Mercury/Mercruiser Engines (Replaces 879031) is designed as a direct replacement for various Mercury and Mercruiser marine engines. It provides an essential solution for maintaining your engine's cooling system performance and reliability.

It serves as a direct interchange for Mercury part number 879031 and Sierra part number 18-3150.

Designed for direct OEM replacement installation.
Engineered for use in marine environments.
The package includes one complete water pump kit.

Part Number Matrix

Use this matrix to confirm equivalent references across OEM and aftermarket brands.

Brand	Part Number
Mercury	879031
Sierra	18-3150

Engine & Model Compatibility

While this kit is designed for a range of Mercury/Mercruiser engines, a specific model compatibility list is not available. We strongly recommend verifying fitment by matching your existing part number to the references provided on this page.

Technical Specs

Product Type: Water Pump Kit
Installation: Direct OEM replacement
Connection: Direct mount
Dimensions: 17.0cm L x 17.0cm W x 13.0cm H
Weight: 0.72 kg (1.58 lbs)

What’s in the Box

1 x Water Pump Kit (equivalent to 879031)

Installation Notes

Disconnect the vessel's battery and shut off the fuel supply for safety.
Drain the engine's cooling system into a suitable container.
Carefully remove the old water pump assembly, noting the position of all hoses and bolts.
Thoroughly clean the pump mounting surface, removing any old gasket material or sealant.
Install the new water pump kit, ensuring the gasket is correctly seated to prevent leaks.
Reconnect all hoses and fasteners, tightening them to the manufacturer's specified torque.
Refill the cooling system with the appropriate coolant mixture.
Reconnect the battery, start the engine, and carefully inspect for any leaks or unusual noises.

Troubleshooting & FAQ

How can I confirm this kit fits my engine?

The most reliable method is to compare the part number from your old water pump to the numbers listed in our Part Number Matrix. Visual comparison with our product images is also recommended.

What are the common signs of a failing water pump?

Symptoms include the engine overheating at idle or low speeds, visible coolant leaks from the pump housing, a loose or wobbly pump pulley, or a grinding/squealing noise coming from the pump assembly.

How often should a marine water pump be replaced?

Replacement intervals vary based on engine hours, operating conditions (saltwater vs. freshwater), and the manufacturer's recommendations. Impellers should be inspected annually, and the entire pump assembly replaced as a preventative measure or when signs of wear appear.

Is a gasket included with this kit?

Yes, this is a complete kit that includes all necessary seals and gaskets required for a standard installation.

Why is my engine still overheating after replacement?

If overheating persists, check for other cooling system issues such as airlocks, a clogged heat exchanger, a faulty thermostat, or collapsed hoses. Ensure the system was properly bled of air after installation.

OEM vs. Aftermarket?

This listing is an aftermarket replacement (not OEM). It is built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility and batch-inspected for consistency.

Shipping speed & cost?

We ship worldwide quickly—typical transit is 5–15 days. Standard shipping is free; expedited options appear at checkout where available.

Warranty & returns?

Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.

Safety & Important Info

Verify images and specifications against your original part. If anything differs—even if your model appears compatible—do not purchase.
This is an aftermarket replacement, not an OEM component.
Professional installation is recommended for safety and performance.

About Sea Sierra

Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.

Payment & Security

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