3886225 Expansion Tank | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta expansion tank from the Cooling System group, weighing 13.11 kg and listed for 14 applications across the D series. It supersedes part number 865123.

🚤 Compatibility

Typically suits:

• Volvo Penta D12C-A MP
• Volvo Penta D12D-A MG
• Volvo Penta D12D-A MH
• Volvo Penta D12D-A MP
• Volvo Penta D12D-B MH
• Volvo Penta D12D-B MP
• Volvo Penta D12D-C MH
• Volvo Penta D12D-C MP
• Volvo Penta D12D-D MP
• Volvo Penta D12D-E MG
• Volvo Penta D12D-E MP
• Volvo Penta D12D-F MP
• Volvo Penta D12D-G MP
• Volvo Penta D12D-H MP

• Engine Family: D

⚙️ Key Features

• 13.11 kg
• Supersedes 865123
• 14 applications across the D series

🔌 Function

Holds the coolant reserve and takes up the expansion as the engine warms, letting air separate out of the circuit and setting system pressure through its cap.

⚠️ Common Signs of Failure

• Coolant loss with no obvious external leak, or steam from the tank
• Level swinging widely between cold and hot
• Coolant weeping at a tank seam or the filler neck
• Engine running hot with air still in the system after bleeding
• Corrosion or scale visible inside the tank

🛠️ Service Notes

• Renew the filler cap and the tank seals with the tank, as a cap that will not hold pressure causes the same symptoms as a failed tank
• Refill and bleed the system properly and check the vent pipework, such as air vent pipe 3886012 where fitted, is clear and rising

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 3886225 → Supersedes 865123

OEM / Related Numbers

• 865123 earlier number superseded by this part

📦 Condition

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