Mercedes-Benz W212 W204 W207 W218 Coolant Expansion Tank - Used Original Parts

Diagnosis and Common Symptoms

On the W204, W212, W207, and W218 platforms, the coolant expansion tank is subjected to extreme heat cycles which eventually degrade the plastic composite. The most common failure mode involves hairline cracks developing along the molding seams or near the return hose nipple, leading to a slow loss of pressure and coolant. Drivers will often see the "Check Coolant Level" warning on the instrument cluster. Additionally, the internal magnetic float for the level sensor can fail or stick; this results in a persistent dashboard warning light even when the fluid level is actually correct. If you smell sweet antifreeze vapors or spot blue/green residue in the engine bay, the tank structure is likely compromised.

Introduction

Replace your leaking or faulty reservoir with a Genuine Used Mercedes-Benz expansion tank. Unlike aftermarket alternatives that often use inferior plastics prone to warping and sensor calibration errors, this original unit ensures perfect fitment and accurate level readings. We have visually inspected and pressure-tested this part to confirm it is free from cracks and leaks, offering a reliable repair solution at a fraction of the dealer price.

Product Details

• Brand: Mercedes-Benz (Genuine)
• Model Compatibility: C-Class (W204), E-Class (W212, W207), CLS-Class (W218)
• Part Name: Coolant Expansion Tank / Reservoir
• Condition: Genuine Used (Tested Working)
• Notes: Unit has been pressure tested for hairline cracks. Includes integrated level sensor functionality verification. Please verify part number matches your specific engine configuration.