A flushometer valve includes a hollow body and a piston assembly disposed inside the hollow body for controlling operation of the flushometer valve. The piston assembly and hollow body define an inlet chamber, an outlet chamber and a pressure chamber. The piston assembly includes a flow guide, a piston top, and an insert. The flow guide is movable relative to the hollow body between an open position, in which the outlet chamber is fluidly connected to the inlet chamber, and a closed position, in which the outlet chamber is fluidly disconnected from the inlet chamber. The piston top is coupled to the flow guide, includes a first material, and has a bleed passage that fluidly connects the pressure chamber and the inlet chamber. The insert is disposed within the bleed passage, includes a second material, and has a bore that fluidly connects the bleed passage and the pressure chamber.