843759 Expansion Tank | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta expansion tank from the Cooling System group, weighing 0.508 kg and listed for 45 applications across the MD, TMD, AD, D, AQAD and TAMD series. It applies from a production change point onwards, and supersedes part numbers 842763 and 846172.

🚤 Compatibility

• Engine Family: MD, TMD, AD, D, AQAD, TAMD, BB, AQD
• Serial Range: MO4257-

Full model list at the end of this description.

⚙️ Key Features

• Applies from a production change point onwards - the catalogue records this as an internal production reference rather than a serial number
• 0.508 kg
• Supersedes 842763 and 846172
• 45 applications across six engine series

🔌 Function

Holds the coolant that the system pushes out as it warms and draws back as it cools, keeping the circuit full.

⚠️ Common Signs of Failure

• Coolant level dropping with no visible leak elsewhere
• Tank crazed, hazed or split at a moulding line
• Stained or crusted coolant traces down the outside
• Cap seat damaged so the system will not hold pressure
• Tank collapsing inwards as the engine cools

🛠️ Service Notes

• Both earlier numbers 842763 and 846172 resolve to this tank, so confirm which production version your engine takes before ordering
• Expansion tank 844062 is the alternative listing at 0.485 kg with a far wider 260 application list — confirm which the installation takes
• Renew the cap and any perished hose to the tank at the same time and pressure test before handing back

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 843759 → Supersedes 842763

OEM / Related Numbers

• 846172 earlier number superseded by this part

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta 2003, 2003R, 2003R SOLAS, 740A, 2003TB SOLAS, 290A, 2003D, 2002B, 2002D, 2003B, 2003B SOLAS, 2003 SOLAS, 2002
• Volvo Penta AD41P-B, AD41B, AD41, AD41A, AD41BJ
• Volvo Penta TAMD41B, TAMD41D, TAMD41M-A, TAMD41A
• Volvo Penta AD31, AD31B
• Volvo Penta D41, D41B
• Volvo Penta MD22A, MD22L
• Volvo Penta TAMD31A, TAMD31B
• Volvo Penta TMD31A, TMD31B
• Volvo Penta TMD41A, TMD41B
• Volvo Penta AD30A
• Volvo Penta AQAD30A
• Volvo Penta AQD40A
• Volvo Penta BB740A
• Volvo Penta MD30A
• Volvo Penta MD31A
• Volvo Penta MD40A
• Volvo Penta TAMD30A
• Volvo Penta TMD22A
• Volvo Penta TMD30A
• Volvo Penta TMD40A