A brake cylinder for a railway vehicle includes a body, a piston assembly including a piston member and a rod having a threaded surface, and a parking brake locking mechanism including a working nut, a locking gear, and a locking pawl, with the working nut having a threaded surface engaged with the threaded surface of the rod. The piston member has a first position and a second position in a direction extending from the second end of the body toward the first end of the body. The working nut is fixed relative to the locking gear. The locking pawl has an unlocked position spaced from the locking gear and a locked position engaged with the locking gear. The piston is restricted from moving from the second position to the first position when the locking pawl is in the locked position.