Abstract: A protection system to prevent the failure of a flywheel caused by an overspeed condition of a fluid pump. A positive displacement pump is coupled to, and driven by, the drive shaft of the fluid pump, and the positive displacement pump circulates a fluid into a discharge manifold. The fluid exits from the discharge manifold through an orifice, and returns to the positive displacement pump to be recirculated. Brake shoes are arrayed around the flywheel, and are connected to hydraulic cylinders, which in turn is connected by conduits to the discharge manifold. A pressure sensitive valve is installed in the conduit between the discharge manifold and the hydraulic cylinder. The pressure sensitive valve permits fluid to flow from the discharge manifold to the hydraulic cylinder whenever the pressure within the discharge manifold exceeds a predetermined level.