Mercedes-Benz C CLC Class CL203 W203 Brake Servo Master Cylinder A0054304030

Mercedes-Benz C CLC Class CL203 W203 Brake Servo Master Cylinder is an original brake system component designed for Mercedes vehicles. It ensures proper assistance for the brake pedal force, which translates into stable, predictable, and safe deceleration during daily operation.

Specifications and technical data

• SKU: rhd-A0054309701-2
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0054309701
• Substitutable numbers: A0054304030, A 005 430 40 30, A0054309701, A 005 430 97 01, A2034303002, A 203 430 30 02, A0054305630, A 005 430 56 30, BG
• Category: Brake Servos

Purpose and function in the brake system

The presented brake servo and master cylinder assembly has been designed specifically for Mercedes-Benz C-Class and CLC models of the CL203 / W203 generation. It is responsible for increasing braking force using vacuum and for precisely metering brake fluid pressure to the wheel circuits. A properly functioning servo with a master cylinder reduces the need for heavy pedal pressure, improving comfort and vehicle control.

This component is crucial when experiencing symptoms such as a hard brake pedal, uneven braking, or increased stopping distance. Replacing the complete servo-master cylinder assembly is often the most effective service solution to restore factory performance parameters of the system.

Construction of the brake servo – master cylinder assembly

The brake servo uses the pressure difference between the vacuum chamber and the atmospheric chamber to assist the driver during braking. The integrated master cylinder converts pedal movement into hydraulic pressure in the lines, supplying the front and rear brake circuits. This configuration ensures:

• stable force transmission from the pedal to the brake calipers,
• repeatable pedal travel characteristics,
• consistent operation with the vehicle's factory ABS/ESP system.

The original design dedicated to specific Mercedes-Benz models minimizes the risk of fitment issues, leaks, or improper system operation.

Benefits of using an original Mercedes component

Using a factory brake servo and master cylinder in a Mercedes-Benz C / CLC Class CL203 W203 provides a number of practical service and operational benefits:

• Full compatibility with the brake system – maintaining the original pedal feel and braking efficiency.
• Proper fitment for mounts, lines, and accessories – no modifications or adaptations required.
• Consistency with factory vehicle safety parameters – the brake system operates according to the manufacturer's specifications.

Thanks to this, the part is suitable both for standard replacement of a worn component and for post-accident repairs where restoring the original geometry and characteristics of the brake system is required.

Condition, verification, and practical application

The offered item belongs to the Brake Servos and Proportioning Valves group and is intended for reinstallation in a vehicle by the customer or a workshop. Before installation, a standard service procedure is recommended: checking for leaks, verifying the master cylinder piston operation, inspecting vacuum ports, and thoroughly bleeding the entire brake system after assembly.

The selection of the correct brake servo and master cylinder should always be confirmed based on vehicle data (model, generation, body type, engine) and information from the manufacturer's catalog. This helps avoid compatibility issues and ensures proper cooperation with the vehicle's electronics.

If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other components from the same group, such as servos, brake proportioning valves, or complete power brake assemblies, check the available parts in the Mercedes Brake Servos and Proportioning Valves category.

Technical support and selection of used components

When working with safety systems such as brakes, it is important to have a conscious approach to selecting used OEM components. It is worth paying attention to inspection procedures, periodic maintenance, and proper operating conditions to maintain stable vehicle performance throughout the year. Additional tips on selecting and servicing components can be found in the article Air conditioning and heating – part selection and maintenance for year-round comfort, which discusses practical principles of working with used OEM elements and service schedules.