
An expansion tank, also known as a coolant reservoir, is a component of the cooling system in a Mercedes-Benz vehicle. Its main function is to accommodate the expansion of the coolant as it heats up and to maintain a constant level of coolant in the system.
The expansion tank is typically made of plastic and is located in the engine compartment, it is connected to the radiator by a hose. The expansion tank has a fill level indicator or a low coolant sensor that indicates when the coolant level is low and needs to be refilled.
The expansion tank also has a pressure cap that maintains the system at the correct pressure and prevents coolant from boiling over. The pressure cap is designed to release pressure when it exceeds a certain level, to prevent damage to the cooling system.
If the expansion tank is damaged or leaks, it can cause the coolant level to drop, resulting in an overheating engine. Regular inspection and replacement of the expansion tank as needed, as part of regular maintenance can help prevent such issues.