Mueller Roll-Up Door L250 - Manual (Page 12)

12 877-2-MUeLLeR
step 11: MaKe sURe tHe top of gUiDe is Bent
step 12: CHeCK DooR opeRation
a If this is not bent; bend over headstop with
Vise grips or an adjustable wrench.
a Once both head stops are securely installed and the top
of the guide is bent over the headstop bar, unlock slide
locks on the bottom bar and check door operation by
lowering and raising the door.