Joe. Kent. Plastic is a strange thing. I've had other things break also for no reason at all. The surface in the break area is like it was polished very shiny and good looking accept for two tiny places where it looks different and roughed. I know this parts are injector molded in one shot. So i asked a guy that works in a company that do injector molding, The explanation he gave me was if the molding/pump get a sudden stop during the process this thing can happen, Plastic looks fine but the parts change temperature during the stop and don't fuse together. And yes it's heavy beams
and it's going to be heavier soon. and longer too.