stupid belt tension question

[evobuilder]

so I have power sterring on my 65 C10 and just for a pulley on the pump. Now I have a STUPID question.... how do I adjust the belt. The only thing I could tell was to loosen the bolt and the bracket andpull up, then tighten.... then adjust at the bolt at the pump. Is this correct?

My only concern is that I slipped and was able to push the PS pump out of adjustment with my hand.... is that bad or is that normal? Seems like there should be a way to "lock" this in place once adjusted.

Any help would be greatly appreciated.