Mini R55 R56 R57 JCW John Cooper Works Rear Left N/S Wheel TRW Brake Caliper

Mini R55 R56 R57 JCW John Cooper Works Rear Left N/S Wheel TRW Brake Caliper is an original braking system component designed for the rear left axle of sporty Mini variants. This used TRW caliper ensures a factory-fit, maintaining the proper operating parameters of the braking system. It is an ideal solution for drivers who want to maintain the structural integrity of their vehicle while optimizing maintenance costs.

Specifications and technical data

• SKU: 6784645
• Mark: Mini (Genuine OE)
• Condition: Used
• OEM Part Number: 6784645
• Substitutable numbers: 6784645, 34216784645
• Location on the vehicle: Rear, Left
• Category: Brake Disc Rotors

Purpose and compatibility with Mini JCW

The presented caliper is designed for the rear left axle of Mini R55, R56, and R57 series models in John Cooper Works versions. Thanks to its design, which complies with Mini factory standards, the following are maintained:

• correct mounting geometry to the steering knuckle and carrier,
• proper brake pad guidance,
• correct interaction with the rear brake disc,
• compatibility with the stock braking system hydraulics.

Such compatibility reduces the risk of installation issues and allows for efficient replacement in workshop or service conditions.

Technical characteristics of the TRW caliper

The TRW brake caliper used in the Mini JCW is a construction adapted for more intensive use typical of sports versions. It is distinguished by:

• stable piston operation ensuring even pressure of the pads against the disc,
• body construction resistant to thermal loads,
• adaptation to the stock Mini braking system in John Cooper Works versions,
• serviceability (bleeding, replacement of wear-and-tear components).

As a result, the caliper can be safely used as a replacement part in vehicles driven both in city traffic and in more dynamic conditions.

Benefits of using an original caliper in a Mini

Using an original caliper in the rear left part of the Mini JCW braking system translates into a number of practical benefits:

• Factory fit – no need for modifications, drilling, or the use of adapters.
• Consistency of braking parameters – maintaining the balance of braking forces between the left and right sides and between the front and rear axles.
• Seamless integration with the existing system – compatibility with the stock brake master cylinder, lines, and rear discs.
• Possibility of further maintenance in accordance with the vehicle manufacturer's procedures.

For users of Mini R55, R56, and R57 in John Cooper Works versions, this is a practical way to maintain the efficiency of the braking system while adhering to the original specification.

Condition, origin, and practical application

The offered caliper is a used component, which allows for an economical repair of the braking system while using a part sourced from a dismantled Mini vehicle. Such components are frequently chosen by workshops specializing in the brand and by informed users who prefer original solutions over replacements of unknown origin. Before installation, a standard service procedure is recommended: checking the technical condition, seals, guide pins, and properly bleeding the system after installation.

Technical support and additional materials

If you want to deepen your knowledge on the safe selection of used braking system components, such as discs, calipers, or ABS components, check out the advice in the article: Second-hand braking system: how to safely choose discs, calipers, and ABS?. This is a practical compendium that will help you verify the condition of parts before installation and avoid common mistakes.

If you are planning a comprehensive repair or upgrade of the braking zone in your Mini and need other elements from the same group, such as discs, pads, or brake lines, check the available parts in the Mini Brake Discs category.