Brake Caliper BMW E90 E91 Front Left N/S Brake Unit Carrier Housing 57/30/348

Brake Caliper BMW E90 E91 Front Left N/S Brake Unit Carrier Housing is an original braking system component from the Brake calipers and carriers group, designed for installation on the front left axle of the vehicle. This used caliper provides a functional service solution, allowing for the restoration of proper brake performance while maintaining factory operating characteristics. It is a practical choice for users looking for parts with a proven design and precise fit for the specific BMW platform.

Specifications and technical data

• SKU: 6773201-5
• Mark: BMW (Genuine OE)
• Condition: Used
• OEM Part Number: 6773201
• Substitutable numbers: 6773201, 34116773201
• Location on the vehicle: Front, Left
• Category: Calipers & Brackets

Purpose and vehicle placement

The presented brake caliper is designed to operate on the front left side of the vehicle, in direct proximity to the brake disc. Its construction is adapted to the architecture of the braking system used in the BMW E90/E91 series, which ensures proper positioning relative to the hub, disc, and brake pads.

Placement on the front axle means that this component is responsible for a significant portion of the vehicle's braking force. A correctly selected and installed caliper allows for stable pad guidance, even pressure application against the disc, and the maintenance of consistent braking efficiency under typical operating conditions.

Construction and operating parameters of the caliper

The technical designation 57/30/348 refers to key design features of the caliper, such as the working diameters of the pistons and the intended range of compatibility with the appropriate disc diameter. This ensures the caliper is matched to the specific configuration of the BMW braking system, minimizing the risk of incorrect component selection.

The construction typical for this BMW generation includes the caliper body, guide pins, and a working piston, which interact with the vehicle's hydraulic brake system. This solution provides:

• stable pad guidance within the caliper,
• appropriate clamping force at a given system pressure,
• the ability to be serviced with standard repair kits.

Benefits of using an original BMW caliper

Using an original caliper from the Brake calipers and carriers group instead of a worn-out element allows for the preservation of factory braking system performance parameters. In practice, this means:

• proper interaction with the existing brake master cylinder and lines,
• correct fitment to the carrier, hub, and brake disc,
• maintenance of the manufacturer-intended braking force characteristics on the front axle.

For the user, this means predictable vehicle behavior during braking, without the need to modify other system components. The original BMW design also facilitates future maintenance tasks, such as pad replacement or guide pin servicing.

Condition, verification, and service application

The item is offered as a used part, which in practice represents a favorable compromise between repair costs and maintaining original technical specifications. Such components are frequently used in post-accident repairs, brake system regeneration, or as a replacement for a worn caliper in daily operation.

Before installation, standard service procedures are recommended, such as checking the condition of working surfaces, seals, and guide pins, as well as using appropriate assembly agents and lubricants intended for brake systems. A properly prepared caliper can work seamlessly with new pads and discs, restoring system efficiency.

Integration with other braking system components

Replacing a caliper on the front axle is often associated with the simultaneous maintenance of other braking system components. It is worth paying attention to the condition of discs, pads, flexible hoses, and brake fluid to achieve a consistent service result and reduce the risk of uneven braking.

If you are planning a comprehensive repair or upgrade of the braking zone in your BMW and need other elements from the same group, such as additional calipers, carriers, or mounting brackets, check the available parts in the BMW brake calipers and carriers category.

For users who want to approach the purchase of aftermarket components consciously, especially when selecting calipers, discs, and ABS elements, the following guide will be helpful: Second-hand braking system: how to safely select discs, calipers, and ABS?. The article contains a practical checklist that facilitates the assessment of the condition of used parts and minimizes the risk of an unsuccessful purchase.