sram guide rsc

Looking for some info bought a bike new 3months ago with these brakes on it they work great as good as or better than my old xt set up.

question is as I didn't get any paper work about how to adjust these brakes how dose the pad adjustment work

I have wound the wheel on the lever both ways fully makes no change to how much travel it takes for the lever to engage the pads.
I removed the pads the other day and noticed i had 3 out of 4 sticky pistons in the calliper so exercised them until they are working again but still the pad adjustment wheel makes no difference.

Thanks

Duncan