Mercedes W166 Brake Servo Booster Master Cylinder Unit A1664300630

Mercedes W166 Brake Servo Booster Master Cylinder Unit is an original brake system component designed for the SUV models of this series. As part of the Brake Servos and Proportioning Valves group, it is responsible for stable brake assistance and proper pressure distribution in the brake circuits. Using an OEM component allows for a technically correct repair without the need for aftermarket alternatives with uncertain parameters.

Specifications and technical data

• SKU: RHD-A1664300630
• Mark: Mercedes (Genuine OE)
• Condition: Used
• OEM Part Number: A1664300630
• Substitutable numbers: A1664300630, A 166 430 06 30, A1664301130, A 166 430 11 30, A1664300201, A 166 430 02 01, A1664300102, A 166 430 01 02
• Part type: Brake Servo & Master Cylinder
• Category: Brake Servos

Purpose and function in the brake system

The presented brake servo-master cylinder unit is designed to work with the hydraulic brake system in the Mercedes W166 body, providing the driver with clear brake pedal assistance. Integrating the servo with the master cylinder reduces the number of connections, which promotes system tightness and facilitates installation in the engine compartment. The properly selected force ratio and operating characteristics of the servo allow for precise braking force modulation, which translates into predictable vehicle behavior during emergency braking, driving with a load, or in urban conditions.

Advantages of using an original Mercedes brake servo

Choosing an original brake servo-master cylinder unit for the Mercedes W166 ensures:

• factory fitment to the mounts and geometry of the brake system,
• preservation of the stock brake pedal operating characteristics,
• compatibility with factory safety systems (ABS, ESP, brake assistants),
• consistency with the manufacturer's service documentation. Additionally, the presence of dedicated interchangeable part numbers facilitates part selection based on manufacturer catalogs and service systems, which minimizes the risk of installing an incorrect component.

Condition, origin, and service application

The component comes from the used Mercedes OEM parts group, which means it retains the original design and operating parameters specified by the manufacturer. This type of component is particularly useful for:

• repairs after brake booster failure,
• eliminating leaks within the master cylinder,
• comprehensive brake system regeneration in vehicles used intensively. Using an original brake servo with master cylinder allows for maintaining system consistency with other brake components, which is important both from a safety perspective and for subsequent computer diagnostics.

Selection, compatibility, and installation aspects

To correctly select this unit for a specific version of the Mercedes W166, it is recommended to verify compatibility based on the OEM part number and available interchangeable numbers in service catalogs. This allows for precise matching of the servo-pump to the engine version, model year, and vehicle equipment configuration. The "master cylinder unit" solution simplifies the installation process – the mechanic replaces the complete assembly, which reduces the risk of leaving worn components within the main brake circuit. A correctly selected and installed assembly restores predictable, stable brake pedal operation and proper functioning of driver assistance systems. If you are planning a comprehensive repair or upgrade of the braking zone in your Mercedes and need other elements from the same group, such as servos, proportioning valves, or complete booster assemblies, check the available parts in the Mercedes Brake Servos and Proportioning Valves category.

Safety, comfort, and service knowledge

A functional brake servo with master cylinder has a direct impact on driving safety, braking distance, and the comfort of operating the brake pedal. Combined with regular maintenance of other brake system components, it allows the vehicle to be kept in a condition consistent with the manufacturer's specifications. When planning broader service work, it is also worth considering systems responsible for driving comfort, such as air conditioning and heating. Practical tips on selecting used OEM components and maintenance schedules can be found in the article Air conditioning and heating – part selection and maintenance for year-round comfort, which helps organize car service work in an economical and technically sound manner.