Volvo Penta Seawater Pump 21212800 – Fits Volvo Penta 8.1L Gas Engines (Replaces 3812518)
Volvo Penta Seawater Pump 21212800 – Fits Volvo Penta 8.1L Gas Engines (Replaces 3812518) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Volvo Penta Seawater Pump 21212800 – Fits Volvo Penta 8.1L Gas Engi...
Product Details
This is a direct-fit aftermarket Volvo Penta Seawater Pump 21212800, engineered for Volvo Penta 8.1L GM-based gasoline engines from 2005 and newer, including the Gi, GXi, OSi, and IPS series. It ensures reliable engine cooling by circulating raw water through the system.
It serves as a direct replacement for Volvo Penta part numbers 21212800 and 3812518, as well as Johnson Pump models 10-13470-03, 10-13569-03, and 10-13569-13.
- Features a simple bolt-on design for straightforward installation.
- Comes with a pre-installed impeller to save time and effort.
- Crankshaft-mounted, beltless design for efficient operation.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 21212800 |
| Volvo Penta | 3812518 |
| Johnson Pump | 10-13470-03 |
| Johnson Pump | 10-13569-03 |
| Johnson Pump | 10-13569-13 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
Designed for specific Volvo Penta 8.1L gasoline engines manufactured in 2005 or later.
| Brand | Model | Stroke | Years | OEM Part No. |
|---|---|---|---|---|
| Volvo Penta | 8.1Gi-G, 8.1Gi-GF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXi-F, 8.1GXi-FF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1OSi-C, 8.1OSi-CF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1Gi-H, 8.1Gi-HF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXi-G, 8.1GXi-GF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1OSi-D, 8.1OSi-DF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1Gi-J, 8.1Gi-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1OSi-J, 8.1OSi-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXi-J, 8.1GXi-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiC-400-J, 8.1GiC-400-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiC-400-Q | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiCE-J, 8.1GiCE-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiCE-M, 8.1GiCE-MF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiCE-P, 8.1GiCE-Q | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiE-JF, 8.1GiE-J | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1OSiE-JF, 8.1OSiE-J | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXiE-JF, 8.1GXiE-J | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiE-K, 8.1GiE-KF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXiE-K, 8.1GXiE-KF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiE-M, 8.1GiE-MF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXiE-M, 8.1GXiE-MF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GXi-MF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiE-P, 8.1GXiE-P | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiI-G, 8.1GXiI-F | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1GiI-H, 8.1GXiI-G | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1IPSCE-JF, 8.1IPSCE-MF | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1IPSCE-PF, 8.1IPSCE-Q | 4-Stroke | 2005 and newer | 21212800/3812518 |
| Volvo Penta | 8.1IPSE-JF | 4-Stroke | 2005 and newer | 21212800/3812518 |
Technical Specs
- Product Type
- Raw Water/Seawater Pump
- Installation
- Bolt-on design with pre-installed impeller
- Connection
- Inlet: 1" Hose Barb, Outlet: 1-1/4" Hose Barb
- Housing Material
- Heavy-duty marine grade casting
- Dimensions
- 12.5" x 17.0" x 23.0"
- Weight
- 3.85 lbs (1.75 kg)
- Fitting Type
- Hose barb connections
- Operating Temperature
- Up to 105°C (221°F)
- Other
- Crankshaft mounted, beltless pulley design; includes grommet for support wire
What’s in the Box
- 1 x Seawater Pump Assembly (21212800)
Installation Notes
- Disconnect the boat's battery and close the raw water seacock.
- Place an absorbent pad under the pump to catch any spillage.
- Loosen the hose clamps and carefully remove the inlet and outlet hoses from the pump.
- Remove the mounting bolts that secure the pump to the engine block or bracket.
- Carefully detach the old pump from the crankshaft.
- Clean the mounting surface and inspect the crankshaft for any wear or damage.
- Align the new pump and slide it onto the crankshaft, ensuring it seats correctly.
- Secure the new pump with the mounting bolts, tightening them to the manufacturer's torque specifications.
- Reconnect the inlet and outlet hoses and tighten the hose clamps securely.
- Open the raw water seacock and reconnect the battery.
- Start the engine and immediately check for any leaks around the pump and hose connections.
- Allow the engine to run for several minutes while monitoring for proper water flow and temperature.
Troubleshooting & FAQ
How do I know if this pump fits my Volvo Penta 8.1L engine?
This pump fits 8.1L GM-based gasoline engines from 2005 and newer. Always verify your engine model against the compatibility table and match the OEM part number (21212800 or 3812518). Visually comparing your old part to the product images is also a critical step.
What are the signs of a failing seawater pump?
Common signs include engine overheating at idle or low speeds, visible water leaks from the pump housing or weep holes, reduced water flow from the exhaust, and unusual grinding or rattling noises coming from the pump assembly.
What is the recommended replacement interval for the impeller?
While the pump housing is built for longevity, the internal flexible impeller is a wear item. We recommend inspecting the impeller annually and replacing it every 1-2 years or 200 hours of use, whichever comes first, depending on operating conditions (e.g., sandy or silty water).
Does this pump include a new impeller?
Yes, this pump assembly comes with a new, high-quality impeller pre-installed to simplify the replacement process and ensure proper initial performance.
Is this a belt-driven pump?
No, this model is a crankshaft-mounted pump. It features a beltless pulley design and is driven directly by the engine's crankshaft.
What should I do if my engine still overheats after replacing the pump?
If overheating persists, check for other cooling system issues such as a clogged seacock or strainer, collapsed hoses, a blockage in the heat exchanger, or a faulty thermostat. Ensure there are no air locks in the system.
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.
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