I have the same trailer. I picked up this link at some point over the years. I haven't had to look too closely at these manuals yet (knock on wood) but I think UFP made quite a few of the trailer components. You actually reminded me that I need to think about replacing the return spring on my brake actuator this winter. I remember this website had a section for troubleshooting a clunk when you start off and the brakes release (which mine is doing).