setting brakes on a 2011 2720

I pulled our 2720 out from storage last weekend and towed it to our spring\summer parking spot. This was the first time i moved it since buying it
last October, i tested our new P3 brake contoller and ultimately had to turn the
brake setting up to 9.3 (techonsha recomends starting at 6.0) just to get minimal
braking. This doesnt seem right. How do i check brake adjustments,and is it hard to readjust? Thanks for any and all advise.

Raddad