A piston assembly for use in a brake assembly has a piston sleeve having a first end, a second end, an external radius, an internal radius, and a cap on the piston sleeve second end. The cap has a first end, a middle portion, and a second end. The cap first end has an external radius and the cap second end has an external radius, wherein the cap first end external radius is smaller than the cap second end external radius. The middle portion is stepped to transition from the cap first end external radius to the cap second end external radius. The cap first end external radius is such that the cap first end slides into the piston sleeve. The cap middle portion has a conical mating surface, and the piston sleeve second end has a corresponding conical mating surface. Further, the cap second end external radius is larger than the piston sleeve external radius.