11033385 Expansion Tank | Genuine Volvo Penta Part

🔧 Product Description

This is a genuine Volvo Penta expansion tank from the cooling system group, supplied in the 12L configuration. It holds the coolant reserve for the closed freshwater circuit, accommodating expansion and contraction as engine temperature changes and providing the fill point for topping up the system. This part number supersedes the earlier 11033336 and serves TD, TWD, TAMD and other inline and V-configuration marine diesel engines.

🚤 Compatibility

Typically suits:

• Volvo Penta TD121G-87
• Volvo Penta TWD1230ME
• Volvo Penta TWD1230VE
• Volvo Penta TWD1231VE
• Volvo Penta TWD1030ME
• Volvo Penta TWD1031VE
• Volvo Penta TD1030VE
• Volvo Penta TAMD102A
• Volvo Penta TAMD102D
• Volvo Penta TAMD103A
• Volvo Penta TAMD122P-A
• Volvo Penta TAMD122P-B
• Volvo Penta TAMD122P-C
• Volvo Penta TAMD162A
• Volvo Penta TAMD162B
• Volvo Penta TAMD162C
• Volvo Penta TAMD162C-B

• Engine Family: TD, TWD, TAMD
• Year Range: Approximately 1980s-2000s, installation controlled

⚙️ Key Features

• OEM Volvo Penta part number 11033385
• Supplied in the 12L configuration
• System group: Cooling System
• Net weight approximately 1.20 kg
• Replaces previous part number 11033336
• Fits TD121, TWD1030/1230, TD1030, TAMD102/103, TAMD122P and TAMD162 series marine diesel engines
• Engine type: Volvo Penta 10-litre marine diesel and Volvo industrial equipment
• System type: Pressurised coolant expansion tank

🔌 Function

The expansion tank stores surplus coolant and allows the freshwater cooling circuit to expand and contract safely with temperature changes, keeping the system full and pressurised. It also provides the filling and level-checking point for engine coolant.

⚠️ Common Signs of Failure

• Coolant weeping, staining or dried residue around the tank body, seams or hose connections
• Cracks, crazing or brittleness in the tank shell from age and heat cycling
• Persistent coolant loss with no other visible leak in the circuit
• Repeated overheating or fluctuating temperature readings caused by loss of system pressure
• Damaged or distorted filler neck preventing the cap from sealing correctly

🛠️ Service Notes

• Check the level cold with the engine stopped, and fill to between the level marks where the tank has them, or to the level given in the workshop manual for your engine — an overfilled system simply pushes coolant out past the cap as it warms
• Use the coolant type and mix specified for your engine and top up with the same; mixing coolant types can destroy the corrosion protection the whole cooling system depends on
• Inspect the tank for hairline cracks, crazing and staining around the seams and the hose spigots, and check the hoses and clips while you are there
• Check the cap seal and that the cap both relieves and draws back properly — a cap that will not vent empties the tank, and one that will not let coolant return collapses a hose
• Never release the cap on a hot pressurised system; let it cool first, and bleed and refill the system as the manual for your engine describes after any work

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 11033385 → Supersedes 11033336

OEM / Related Numbers

• 3828863 rubber collar
• 1674083 75kPa pressure cap
• 1542591 50kPa pressure cap
• 844624 30kPa pressure cap
• 11075152 tensioning band
• 11025992 mounting pin
• 865573 mounting bracket
• 976944 washer
• 948645 flange lock nut

Aftermarket / Verified Equivalents

• SRP: ET-33385

📦 Condition

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