Water Pump Kit – Fits MerCruiser Alpha, Bravo & TRS (Replaces 46-807151A14, 807151A7)
Water Pump Kit – Fits MerCruiser Alpha, Bravo & TRS (Replaces 46-807151A14, 807151A7) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
Worry-free returns
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).
If you need to return an item, simply login to your account, view the order using the "Complete Orders" link under the My Account menu and click the Return Item(s) button. We'll notify you via e-mail of your refund once we've received and processed the returned item.
Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Water Pump Kit – Fits MerCruiser Alpha, Bravo & TRS (Replaces 4...
Product Details
This Sierra 18-3150 Water Pump Kit – Fits MerCruiser Alpha, Bravo & TRS is a complete assembly designed for MerCruiser Alpha engines with freshwater cooling (FWC), all Bravo I/II/III and TRS sterndrives, and various inboard marine engines. It is engineered for models that utilize a plastic, one-piece body sea water pump.
This kit serves as a direct replacement for MerCruiser part numbers 46-807151A14 and 46-807151A7, as well as GLM 12088 and Mallory 9-48350.
- Installs as a complete, direct-replacement assembly.
- Designed as an updated, one-piece housing that can replace older two-piece pump designs.
- Includes the pump body, impeller, wear plate, O-rings, and all necessary hardware for a full replacement.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| MerCruiser | 46-807151A14 / 46-807151A7 |
| GLM | 12088 |
| Mallory | 9-48350 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For MerCruiser applications, this pump fits a wide range of sterndrive and inboard engines equipped with a one-piece plastic sea water pump. Please verify your OEM part number before ordering.
| Model | Rated HP | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Alpha (FWC) | Various | 4-Stroke | 46-807151A14 | With internal pump, closed cooling |
| Bravo | Various | 4-Stroke | 46-807151A14 | All Bravo sterndrives |
| TRS | Various | 4-Stroke | 46-807151A14 | All TRS sterndrives |
| Inboard Marine | Various | 4-Stroke | 46-807151A14 | Models with 1-piece pump housing |
| 330 (B-W) | 330 | 4-Stroke | 46-807151A14 | |
| Hi-Performance | Various | 4-Stroke | 46-807151A14 | WITHOUT solid plate front mount |
Technical Specs
- Product Type
- Sea Water Pump Body & Impeller Kit
- Installation
- Direct replacement, complete assembly
- Housing Material
- Plastic (one-piece design)
- Housing Color
- Black
- Dimensions
- 142 × 132 × 155 mm (5.6 × 5.2 × 6.1 in)
- Weight
- 0.91 kg (2.0 lb)
- Warranty
- 2-year limited (Sierra/SeaStar Solutions)
- Other Technical Attributes
- Can replace 2-piece housing sea water pumps with this 1-piece design
What’s in the Box
- 1 x Water Pump Assembly (46-807151A1)
- 1 x O-Ring (25-33465/25-8M0214925)
- 5 x Screw Hex Head .312-18 x 3.250 (10-74191/8M0204669)
- 2 x Screw Hex Head .312-18 x 2.68 (10-807356)
- 5 x Washer (.344 x .688 x .065) Stainless Steel (12-814806)
- 1 x Impeller (47-59362T1)
- 1 x Quad Ring (25-94288/25-8M0215007)
- 1 x Wear Plate Outer (94576/8M0204674)
Installation Notes
- Disconnect the negative battery cable and close the engine's raw water seacock.
- Place a catch pan under the pump and drain the system by loosening the drain plugs or hoses.
- Carefully label and disconnect the inlet and outlet water hoses from the pump.
- Remove the mounting bolts securing the old pump assembly and remove it from the engine.
- Thoroughly clean the mounting surface on the engine, ensuring it is free of old gasket material or sealant.
- Position the new O-ring or gasket correctly on the new pump.
- Mount the new pump assembly, ensuring it is properly aligned, and tighten the new mounting screws to the manufacturer's specified torque.
- Reconnect the water hoses to the correct ports and secure them with clamps.
- Open the seacock and reconnect the battery cable. Start the engine and immediately check for any water leaks around the pump and hose connections.
Troubleshooting & FAQ
How do I know if this pump fits my specific MerCruiser model?
This kit is designed for MerCruiser Alpha (FWC), Bravo, and TRS sterndrives, plus inboards using a one-piece plastic pump body. The most reliable way to ensure a match is to verify your original OEM part number against the cross-reference list, which includes 46-807151A14 or 46-807151A7.
Can this 1-piece pump replace an older 2-piece housing?
Yes, this 1-piece plastic body pump assembly is designed as an updated, direct replacement for older 2-piece housing sea water pumps used on compatible MerCruiser engines.
What are the signs of a failing water pump?
Common symptoms include engine overheating at idle or low speeds, a weak or no stream of water from the tell-tale outlet, visible cracks or leaks on the pump housing, or a grinding noise from the pump area. A worn impeller is the most frequent cause of poor cooling performance.
How often should the water pump impeller be replaced?
As a general maintenance guideline, the rubber impeller inside the sea water pump should be inspected annually and replaced every 1 to 2 years. Replacement frequency depends on operating hours, water conditions (sandy, silty, or saltwater environments accelerate wear), and storage conditions.
Will I need any other parts for installation?
This is a complete kit that includes the pump housing, impeller, wear plate, O-rings, and all required mounting screws and washers. No other components should be necessary for a standard replacement.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 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/specifications vs 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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