On 4 separate occasions the brakes on this Explorer failed to engage. The first incident happened as I was backing out of my garage and the brakes did not engage immediately. This resulted in my damaging our trellis. I was traveling at about 5 mph This happened Sept. 2023. The second incident happened as I was coming out of the car wash and applied the brake, but it did not engage and this resulted in a small fender bender with the car in front of me.- Again very slow speed, about 2 MPH Happened in November 2023. The third incident was on the road as I approached a car stopped for a red light. Again the brakes failed to engage, but I was able to avoid the car in front of me by swerving into the lane to the left. Fortunately no car was approaching on that lane this happened November 2023. The final incident again was on the road. The car in front of me was stopped for a left turn and I applied the brakes, the car did not stop so I swerved to the right onto a lawn and side swiped a tree before the brakes finally took hold. I was slowed down to about 30 MPH happened inJanuary 2024.. This failure in the car braking system has resulted in a substantial money loss . After these incidents I am no longer driving the car. I contacted the dealership and they would not look at the vehicle until it was repaired. We will be returning the car to the dealership for their evaluation of the problem.