21281430 Expansion Plug | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta expansion plug used to close a machined core or service opening in the cylinder block or flywheel-housing area. Correct diameter, interference and installation depth are essential to prevent coolant or oil leakage.

🚤 Compatibility

Typically suits:

• Volvo Penta D1-30
• Volvo Penta D1-30B
• Volvo Penta D1-30F
• Volvo Penta MD2010B
• Volvo Penta MD2010-C
• Volvo Penta MD2010-D
• Volvo Penta MD2020B
• Volvo Penta MD2020-C
• Volvo Penta MD2020-D
• Volvo Penta MD2030
• Volvo Penta MD2030B
• Volvo Penta MD2030-C
• Volvo Penta MD2030-D

• Engine Family: D, MD
• HP Range: 30 HP

⚙️ Key Features

• Genuine Volvo Penta engine-block expansion plug
• Precision diameter for the assigned machined bore
• Closes a casting core or service opening
• Requires correct seating depth and clean bore
• Replace if corroded, leaking or disturbed
• Engine type: Volvo Penta marine or industrial diesel
• 2 used per assembly

🔌 Function

Permanently closes the assigned casting opening and retains coolant or oil within the engine passage.

⚠️ Common Signs of Failure

• Coolant or oil seeping from a machined opening in the block or flywheel housing area
• Rust staining or a crusty deposit trailing down the casting below the plug
• Plug visibly dished, proud of the casting, or pushed part way out
• Corrosion pinholing through the face of the plug
• On removal, the machined bore found corroded or scored so the new plug cannot grip

🛠️ Service Notes

• Clean the bore back to bright metal and check it for scoring before pressing the new plug in - a corroded bore is the usual reason a replacement leaks
• Drive the plug to the specified depth; too deep or too shallow both leak
• Supersedes 3886429 and 861803, the earlier number catalogued as a plug blank

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21281430 → Supersedes 3886429

OEM / Related Numbers

• 861803 earlier number superseded by this part
• 3886429 earlier number superseded by this part
• 3582307 - associated cylinder-block reference
• 3886427 - other position-specific block-plug references; not interchangeable without schematic confirmation
• 3583696 - other position-specific block-plug references; not interchangeable without schematic confirmation
• 3583697 - other position-specific block-plug references; not interchangeable without schematic confirmation
• 861805 - other position-specific block-plug references; not interchangeable without schematic confirmation
• 3807215 - other position-specific block-plug references; not interchangeable without schematic confirmation
• 861806 - other position-specific block-plug references; not interchangeable without schematic confirmation

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging