Smart A451 C451 Brake Servo Fluid Reservoir Expansion Tank Bottle A4514300102

The Smart A451/C451 brake fluid reservoir is an original Mercedes brake system component designed to work with the brake booster. It ensures stable fluid storage, proper bleeding, and safe supply to the brake master cylinder, which translates to predictable brake pedal response and comfortable daily driving.

Specifications and technical data

• SKU: RHD-A4514300102
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A4514300102
• Substitutable numbers: A4514300102, A 451 430 01 02
• Part type: Brake Fluid Reservoir
• Category: Reservoirs & Caps

Intended Use and Role in the Braking System

The presented reservoir belongs to the category of brake fluid reservoirs and caps and works with the brake booster in Smart A451/C451 models. It is responsible for maintaining the correct fluid level, compensating for volume changes due to temperature fluctuations, and ensuring stable supply to the brake circuits.

Thanks to its factory OEM design, the reservoir is precisely matched to the engine bay geometry, mounting points, and hose connections, which facilitates installation and minimizes the risk of leaks due to misalignment.

Construction and Performance Parameters

The expansion tank is made of a material resistant to brake fluid and the typical operating temperatures of the system. The transparent or translucent body structure (characteristic of this type of part) allows for visual inspection of the fluid level without the need to remove the component.

• Factory-fitted for the brake booster in Smart A451/C451 vehicles.
• Designed to work with typical brake fluids used in passenger cars.
• Construction allows for easy servicing and fluid level checks.

Original sourcing from the Mercedes group means adherence to the design parameters specified by the vehicle manufacturer, which is crucial for maintaining stable system pressure and proper booster operation.

Condition, Selection, and Installation

This part is offered as a used item, allowing for economical brake system repair while maintaining original specifications. Before installation, standard servicing procedures are recommended: checking for leaks, cleaning connections, and verifying compatibility with the existing brake booster and lines.

To select the correct reservoir for a specific vehicle, it is advisable to verify compatibility with the OEM part number and any interchangeable numbers in the specifications tab. This helps avoid installation issues and ensures correct positioning of the reservoir relative to the brake booster and master cylinder.

For users planning a more extensive brake system upgrade or repair, the following guide will be useful: check how to safely choose used brake system components, where you will find a practical checklist for selecting discs, calipers, and ABS components.

Benefits of Using an Original Reservoir

Using the factory expansion tank in the Smart A451/C451 braking system offers a range of practical benefits:

• Mounting Compatibility – maintains original mounting points and connection geometry.
• Stable System Operation – ensures proper circulation and volume compensation of brake fluid.
• Hassle-Free Servicing – easy fluid level checks and access to the cap during inspections.
• Consistency with Other System Components – no need for modifications to brake lines or the booster.

By adhering to factory specifications, this expansion tank is a sensible choice for drivers who want to restore full braking system functionality while maintaining compliance with the vehicle manufacturer's original design solutions.