Mercedes-Benz C W203 OM611 Radiator Expansion Tank Top Coolant Hose A2035010682

Mercedes-Benz C W203 OM611 Radiator Expansion Tank Top Coolant Hose is an original cooling system component from the Lines, hoses and pipes group, designed for use in Mercedes vehicles equipped with the OM611 engine. This used component allows for a technically correct replacement of a worn or leaking hose while maintaining the factory coolant routing geometry and proper compatibility with other system elements.

Specifications and technical data

• SKU: A2035010682
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A2035010682
• Substitutable numbers: A2035010682, A 203 501 06 82, BG
• Category: Hoses, Lines & Pipes

Purpose and function in the cooling system

The expansion tank hose in the OM611 engine is responsible for a stable connection between the tank and the rest of the cooling system, enabling proper fluid circulation and compensation for volume changes. A properly selected hose reduces the risk of engine overheating, facilitates system bleeding, and ensures predictable engine operating temperatures.

In the event of leaks, drops in fluid levels, or visible damage to the rubber, replacing the hose with a functional part is one of the basic service procedures that allows for restoring the proper operation of the cooling system without interfering with other components.

Construction and fitment for Mercedes-Benz C W203 OM611

The offered hose has been designed specifically for the engine bay geometry of the W203 model with the OM611 unit, ensuring it maintains the correct routing between the expansion tank and the rest of the installation. The appropriate shape and diameter of the connectors allow for a tight connection with factory clamps and ports, without the need for modifications or the use of adapters.

Its original Mercedes origin ensures compliance with factory standards for material quality, temperature resistance, and operating pressure typical for the OM611 engine. As a result, the hose works seamlessly with the stock water pump, radiator, and thermostat, without introducing unwanted changes to the flow characteristics.

Used condition and service aspects

The item is offered in used condition, which allows for an economical replacement of the hose while maintaining the manufacturer's original specifications. Before installation, a standard visual inspection is recommended to check for signs of wear, such as micro-cracks, abrasions, or excessive material hardening, as well as checking the sealing surface at the connectors.

During installation, it is worth paying attention to:

• proper positioning of the hose relative to other components in the engine bay,
• selection of appropriate hose clamps with the correct clamping force,
• thorough bleeding of the cooling system after refilling with fluid.

Benefits of using an original expansion tank hose

Using a hose dedicated to the specific Mercedes-Benz C W203 OM611 configuration ensures:

• stable cooling system operation due to the preservation of factory cross-sections and hose lengths,
• secure fitment to stock mounts and routings in the engine bay,
• reduced risk of leaks resulting from poor fitment of universal aftermarket replacements.

For workshops and individual users, this means predictable installation time, no need for system modifications, and easier diagnostics of potential future faults.

Product group and selection of other components

The expansion tank hose belongs to the Lines, hoses and pipes group, which are components responsible for transporting working fluids in the vehicle. In service practice, it is often replaced together with other coolant hoses to minimize the risk of further leaks shortly after the repair.

If you are planning a comprehensive repair or upgrade of the engine area in your Mercedes and need other components from the same group, such as coolant hoses, return hoses, or breather pipes, check the available parts in the Mercedes Lines, hoses and pipes category.

Additional technical support

When working on the cooling system, the question often arises whether to invest in repairing an existing engine or consider replacing it. To better assess the profitability of such a decision and learn the key stages of component verification, it is worth reading the guide: Buying a used engine: 5 things you must check before installation.