Audi A4 B9 8W Brake Caliper Wheel Braking Unit Rear Right O/S 300X12 8W0615404M

Audi A4 B9 8W Brake Caliper Wheel Braking Unit Rear Right O/S 300X12 is an original brake system component from the Brake calipers and carriers group, designed for installation on the rear right axle of the vehicle. This used caliper allows for a technically sound repair of the braking system while maintaining factory performance characteristics and fitment to the Audi design.

Specifications and technical data

• SKU: 8W0615404M
• Mark: Audi
• Condition: Used
• OEM Part Number: 8W0615404M
• Substitutable numbers: 8W0615404M, 8W0 615 404 M
• Location on the vehicle: Rear, Right
• Category: Calipers & Brackets

Purpose and function in the braking system

The presented caliper is dedicated to the rear right side of the vehicle, ensuring proper fitment to the suspension geometry and the brake disc of a specific diameter and working thickness. The component is responsible for stable brake pad guidance, even pressure application to the disc, and maintaining consistent braking force on the rear axle.

Thanks to a design consistent with Audi's factory specifications, the caliper works with the standard hydraulic system, maintaining predictable operating characteristics, which is essential for both safety and driving comfort.

Benefits of using an original Audi caliper

Using an original brake caliper in the Audi A4 B9 8W allows for maintaining the consistency of the entire braking system with the vehicle's factory specifications. In practice, this means:

• proper fitment to the carrier, disc, and brake pads on the rear right axle,
• maintaining the manufacturer-intended braking force balance between the front and rear,
• compatibility with standard brake lines and other system components,
• reducing the risk of uneven wear of pads and discs on the right side.

For the user, this means stable, repeatable brake performance and easier diagnostics and maintenance in the future, as operating parameters remain consistent with the manufacturer's documentation.

Installation and operational characteristics

The caliper is designed for installation in the rear part of the vehicle on the passenger side. Such placement requires maintaining the correct orientation of the component relative to the hub, disc, and mounting points on the control arm or steering knuckle. In practice, the installation involves:

• bolting the caliper to the factory mounting points in the suspension,
• connecting the brake line according to the fluid flow direction,
• bleeding the system to restore full braking efficiency.

The used component allows for an economical repair of the braking system while maintaining correct geometry and compatibility with other rear axle components.

Selecting a used brake caliper

When choosing a used caliper for an Audi, it is worth paying attention to compatibility with the specific body version and braking system configuration (diameter and type of disc, type of pads, mounting design). It is also important that the component comes from the same design group as the one originally used in the vehicle, which facilitates installation and reduces the risk of fitment issues.

If you want to deepen your knowledge on the safe selection of used braking system components, such as discs, calipers, or ABS system parts, it is worth using the practical tips included in the article: Braking system second-hand: how to safely choose discs, calipers, and ABS?.

Expanding the Audi braking system

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

For those who want to better understand how using original, used components affects the preservation of the vehicle's character, the material dedicated to the brand's philosophy and the role of spare parts may also be helpful: Audi and emotions in their purest form. How do used parts help maintain the brand's DNA?.