no experience with your specific kit, but the place to start would be with some Loc-tite and a torque wrench. If the kit didn't come with torque specs, a visit to the library for a Machinery's Handbook, or an online search for torque values for the size and grade of hardware you are using would be a start.If the hardware was loose, it would cause things to vibrate, and that would lead to metal fatigue and failure of the part.are the breaks in the brackets a clean snap, or are the edges showing more of a rough edge? A clean break, as if they were cut by a saw are indicative of a materials issue... material too hard, impacts breaking the metal, where the rougher looking edges are an indication of fatigue.