BMW E81 E82 E87 LCI E88 123d Brake Servo Unit Master Cylinder 6791063

Brake booster with brake master cylinder for BMW 123d for E81, E82, E87 LCI, and E88 models is an original component of the braking system from the BMW group, designed for precise integration with the factory installation of these body versions. This used sub-assembly ensures the maintenance of proper braking assistance characteristics, translating to stable, predictable operation of the braking system in 1 Series cars with the 123d engine.

Specifications and technical data

• SKU: rhd-6791063
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6759450
• Substitutable numbers: 34326764117, 6764117, 34336791700, 6791700, 34336779722, 6779722, 6785665, 34316764132, 6764132
• Category: Brake Servos

Purpose and Compatibility

The offered brake booster integrated with the master cylinder has been designed specifically for BMW 1 Series models: E81, E82, E87 after facelift (LCI), and E88 in the 123d version. This ensures correct mounting geometry, appropriate force leverage, and compatibility with the vehicle's factory hydraulic and electronic systems.

The component belongs to the category of brake boosters and force regulators, meaning it is responsible for assisting the force applied to the brake pedal and ensuring correct pressure distribution within the brake circuits. Using an original BMW OE sub-assembly minimizes the risk of compatibility issues and ensures consistency with other system components.

Construction and Function of the Brake Booster + Master Cylinder System

The brake booster works in conjunction with the master cylinder, forming a crucial assembly responsible for generating and assisting pressure in the braking system. In practice, this means:

• reducing the force the driver needs to apply to the brake pedal,
• stable pressure delivery in the brake circuits,
• proper cooperation with safety systems such as ABS or stability control,
• maintaining the factory "feel" of the brake pedal characteristic of the BMW 123d.

By preserving the original design, the booster + master cylinder system allows for a rapid, repeatable increase in pressure within the brake lines, which is particularly important during dynamic driving and in emergency situations.

Benefits of Using an Original BMW Brake Booster

Choosing an original BMW OE component for this vehicle group offers a range of practical advantages:

• Factory Fitment – correct mounting points, pushrod length, and brake pedal operation geometry.
• Braking System Consistency – maintaining the manufacturer's intended assistance and braking force delivery characteristics.
• Part Number Selection Capability – the presence of OEM numbers and interchangeable numbers facilitates verification of compatibility with a specific car configuration.
• Cost Savings Compared to a New Sub-assembly – a used component allows for reduced repair costs while maintaining original specifications.

For workshops and private users, this means a lower risk of complaints, no need for installation modifications, and faster assembly.

Condition, Verification, and Preparation for Installation

The sub-assembly is from a dismantled vehicle and is offered as a used original BMW part. Such components are typically verified for leaks, the condition of ports, mountings, and the operation of the booster mechanism. Before installation, the standard workshop procedure is recommended: checking the vacuum system, brake lines, and proper bleeding of the system after replacement.

To maximize the potential of used brake system components and other dismantled parts, it is worth familiarizing yourself with the practical tips contained in the article: How to Extend the Lifespan of Used Car Parts – A Practical Guide from Global Parts. You will find proven maintenance and operation methods there that help extend the trouble-free working life of parts.

Why Choose This Booster + Master Cylinder Kit for BMW 123d

This brake booster assembly with a master cylinder is specifically designed for the BMW 1 Series in the 123d version, ensuring high compatibility with the vehicle's factory configuration. Its original origin from the BMW brand means maintaining the parameters intended by the manufacturer, and its belonging to the brake boosters and force regulators category guarantees it is the correct choice for repairing or restoring the full functionality of the braking system.

If you are looking for other components from this group or want to compare solutions for different models, use our category: check other brake boosters and force regulators available in our offer. This will make it easier to select the appropriate component for your specific BMW version.