Brake Disc Mercedes W204 Rear Left Right N/O/S Wheel Brake Disc A0004231212

The Mercedes W204 Rear Brake Disc is an original brake system component designed for the left and right side of the rear axle. This product comes from disassembly, making it a sensible choice for users seeking OEM parts with preserved factory fitment for specific Mercedes C-Class W204 versions. It's a practical solution for repairs where structural compatibility and predictable brake system performance are crucial.

Specifications and technical data

• SKU: A0004231212
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A0004231212
• Substitutable numbers: A0004231212, A 000 423 12 12
• Location on the vehicle: Rear, Right, Left
• Category: Brake Disc Rotors

Intended Use and Fitment for Mercedes W204

The presented rear brake disc for Mercedes W204 is designed as a component for the rear axle, with the possibility of installation on both the left and right sides. This placement on the vehicle allows for flexible use of the part when servicing one side or when replacing both discs on the rear axle simultaneously.

Original sourcing from the Mercedes group means preserved correct geometry, appropriate working profile, and compatibility with factory calipers and brake pads used in a given W204 variant. This minimizes the risk of issues with judder, uneven wear, or improper interaction with the ABS and ESP systems.

Technical and Functional Characteristics

The rear brake disc in the Mercedes C-Class W204 is responsible for stable deceleration, especially in situations where the brake force distribution system heavily utilizes the rear axle. The design selected by the manufacturer ensures:

• an appropriate friction surface for standard brake pads,
• proper disc stiffness to limit thermal deformation,
• correct positioning relative to the hub and caliper,
• consistency with the vehicle's factory safety systems.

The placement on the vehicle, specified as rear, right, and left side, allows this disc to be treated as a universal component for both sides of the axle, simplifying service logistics and part selection for phased repairs.

Used Condition and Practical Aspects

The offered brake disc is in used condition, which is important information for those planning an economical repair while maintaining original manufacturer specifications. This type of disassembled component allows for cost reduction compared to new aftermarket parts, while still maintaining factory fitment parameters for the hub, caliper, and brake hardware.

Before installation, each used disc should be inspected for working thickness, any lip formation, friction surface corrosion, and radial runout. Proper preparation (cleaning of the contact surface with the hub, flatness check) is crucial for braking comfort and the absence of vibrations at the brake pedal.

Application in the Brake System and Safety

The Mercedes W204 brake system is designed as a cohesive system where the disc, pad, caliper, and electronics (ABS, ESP) work together in a precisely defined manner. Using an original rear brake disc helps maintain:

• stable and predictable operation of braking assistance systems,
• even pad wear on the rear axle,
• correct brake force balance between the front and rear of the vehicle,
• proper system operation (reduced noise and vibrations).

For users who want to make informed purchasing decisions for disassembled parts, a detailed discussion of evaluation criteria for such components will be useful. For this purpose, it is worth reading the guide: Used Brake System: How to Safely Choose Discs, Calipers, and ABS?, which describes step-by-step what to look for when selecting used brake components.

Expanding Mercedes Brake System Service

If you are planning a comprehensive repair or upgrade of the braking area in your Mercedes and need other components from the same product group, such as additional discs, compatible pads, or supplementary brake lines, check the available parts in the Mercedes Brake Discs category.

By using original components from the same product group, you can maintain the technical consistency of the entire system, which translates to predictable vehicle behavior during daily operation and in emergency situations.