Volvo Penta Seawater Pump 21212800 – Fits Volvo Penta 8.1L Gas Engines (Replaces 3812518)

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.

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.

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

1. Disconnect the boat's battery and close the raw water seacock.
2. Place an absorbent pad under the pump to catch any spillage.
3. Loosen the hose clamps and carefully remove the inlet and outlet hoses from the pump.
4. Remove the mounting bolts that secure the pump to the engine block or bracket.
5. Carefully detach the old pump from the crankshaft.
6. Clean the mounting surface and inspect the crankshaft for any wear or damage.
7. Align the new pump and slide it onto the crankshaft, ensuring it seats correctly.
8. Secure the new pump with the mounting bolts, tightening them to the manufacturer's torque specifications.
9. Reconnect the inlet and outlet hoses and tighten the hose clamps securely.
10. Open the raw water seacock and reconnect the battery.
11. Start the engine and immediately check for any leaks around the pump and hose connections.
12. Allow the engine to run for several minutes while monitoring for proper water flow and temperature.

Troubleshooting & FAQ

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.
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