It lost power brakes during my driving at 45 miles/hour. the vehicle couldn't stop more than 200 yard before a traffic light. i almost hit into traffic which runs at 55 miles per hour. the car drove about 25000 miles when power brakes failed. porsche said vehicle's vacuum pump broken. they fixed. i asked them what is life for a vacuum pump, they rejected to answer. i asked them why the vacuum pump failed, they said it was scrapped, they don't know. i asked them how they are sure the new one would be good. they told me that is why they provided 4 years warranty/50000 miles warranty. i told them it is safety parts, if they can't tell me what's wrong, i don't feel comfortable to drive. it is horrific experience when power brake lost, the car out of control, couldn't stop. i am lucky i didn't hit anyone because no one in front of and luckily again the car stopped about 20 yards before traffic lane on route 55 in il.