While parking in San Francisco after driving for about 100 miles, the brakes felt they had lost all power, the pedal was pressed down to the floor and caused the braking distance to increase drastically. There was a fence post to the left of my truck. So I was going to go forward a little then back up and straighten out to pull forward and finish parking. Going slow 3-5MPH I pressed the brake and the truck kept going forward, I felt a shake from the brake pedal and then no pressure, straight to the floor, then the brake pedal didnât return up. i kept pressing/pumping the brake pedal but still felt like there was no power at all. When you released the brake pedal the pedal would not return to the top like normal. So the truck would not stop, it felt like forever, but when the truck did stop it had just come to rest on the fence post left of me, causing a small dent on the, rear passenger, driver side door. This was really scary because I was parking on a ocean pier and I though I was going to go into the fence in front of me and then into the water. I know now that that was most likely not going to happen because of the low speed I was going at but non the less SUPER SCARY. So now I have a dent on my truck and I am also scared to drive the truck because the brakes might not work when I need them too.