A sliding door assembly includes a door frame with a top trim member, a bottom sill, and side jambs connected between the top trim member and the bottom sill, and a primary sliding panel secured in the door frame. The top trim member includes a track configured to support a weight of the primary sliding panel and prevent the primary sliding panel from coming off the track. Other features include an interlock mechanism to limit relative movement using multiple sliding doors and a brake mechanism to secure the doors in position when the door handle is released. A drop window includes features to accommodate for manufacturing tolerances and box frame assemblies that are out of square.