At restaurant on 6/1/25, backed out of parking spot. Drove about 30 ft to parking lot exit. Turned onto side street to go to light and turn on main street. About 3 or 4 car lengths from exit to light. Side street sloped down about 20-30 degrees. Brakes would not stop van. Not sure if brakes slowed down van as going slow. However, brake pedal pushed hard down to floor but did not stop van. If hit gas pedal van would have accelerated and engine raced causing acceleration and more damage. No damage to back of vehicle I hit. Very minor damage to my van. Tried yesterday and today to replicate (in isolated locations and with no other vehicle near) the vanas conditions at time of incident. I will be contacting dealer. There is no recall. Do not know if anyone else had this problem or if dealer can find any issue. Notifying NHTSA to advise of this potential systemic issue. Iall follow up with results of interaction with dealer.