Description Reviews The MINI Power Brake Booster Vacuum Line for the Automatic MCS is a part that when it breaks you need it ASAP! We have never seen a line fail, but as these cars age the line breaks the nipple off at the check valve. This makes the line useless and makes braking a lot harder. As a temporary fix you can glue it back together, but this will only last for a very short time. As a full performance and maintenance shop we always have one in stock just in case. This comes with everything you need to do the job correctly so that you have brakes when it matters.