Mini Cooper One R55 R56 R57 Brake Master Cylinder Reservoir Tank Cap 6770607

The Mini Cooper R55 R56 R57 Brake Pump Reservoir Cap is an original brake system component from the Brake Boosters and Proportioning Valves group, designed for Mini series R models. The precisely fitted cap ensures a tight seal for the brake pump reservoir, contributing to stable system operation and maintaining the correct fluid level. A used OEM component is a sensible choice for drivers seeking a proven, factory-original solution at an attractive price.

Specifications and technical data

• SKU: 6770607
• Mark: Mini (Genuine OE)
• Condition: Used
• OEM Part Number: 6770607
• Substitutable numbers: 34336770607, 6770607, KZ, 34301164909, 1164909
• Category: Brake Servos

Purpose and Function in the Braking System

The Brake Pump Reservoir Cap is responsible for securely closing the brake fluid reservoir, limiting the risk of contamination and uncontrolled fluid loss. In Mini Cooper R55, R56, and R57 vehicles, it works in conjunction with components from the Brake Boosters and Proportioning Valves group, supporting the proper functioning of the entire system.

Using an original cap is particularly important due to:

• maintaining the proper seal of the braking system,
• stable operating conditions for the brake booster and proportioning valve,
• correct pressure compensation within the fluid reservoir.

Compatibility and Part Identification

The product comes from the Mini line and is an OEM part, which facilitates fitting to specific R55, R56, and R57 body styles. Thanks to assigned part numbers and interchangeable numbers, precise identification of the component in manufacturer catalogs and parts selection systems is possible, minimizing the risk of ordering errors.

If you have any doubts during selection, it is advisable to compare the shape and mounting method of the cap with the photos and factory markings on your existing part to confirm full compatibility with your Mini's braking system.

Condition, Advantages, and Practical Application

The offered cap is in used condition, meaning it comes from a disassembly but retains the functionality required for further operation. Choosing such a solution allows for reduced repair costs while maintaining the original vehicle manufacturer's specifications.

The main advantages of this component include:

• factory fit for Mini series R brake pump reservoirs,
• maintenance of operating parameters as intended by the manufacturer,
• possibility of quick replacement as part of standard servicing procedures.

Replacing the cap is particularly recommended when the existing component shows signs of mechanical damage, leaks, or worn seals, which can affect braking safety and comfort.

Service, Operation, and Durability of a Used Part

To maximize the potential of a used component, it is advisable to ensure proper installation and regular visual inspection of the cap and reservoir area. Maintaining cleanliness around the brake fluid filler neck reduces the risk of contaminants entering the system.

Practical tips for longer and trouble-free operation of disassembled parts, including braking system components, can be found in the article How to Extend the Lifespan of Used Car Parts?, which describes proven methods for maintenance and technical condition checks.

Expanding the Mini Braking System

If you are planning a comprehensive repair or upgrade of the braking area in your Mini and need other components from the same group, such as a brake booster, proportioning valve, or related mounting parts, check the available parts in the Mini Brake Boosters and Proportioning Valves category.