Genuine OEM BMW Brake Servo Unit Hose, part number 11667797255. This hose is a vital link in the braking system, connecting the brake servo unit to a source of vacuum, typically the intake manifold. It transmits vacuum pressure to the servo, which in turn amplifies the force applied to the brake pedal, providing power assistance. The correct routing and sealing of this hose are critical for effective braking. Genuine OEM hoses are designed with specific materials and dimensions to withstand engine bay temperatures and vacuum pressures, ensuring reliable brake assist.