power steering

About a month ago, my family took a trip in our 2015 GMC Acadia SLT. (Roughly 89k miles) My wife noticed a strange feeling in the steering wheel when she would turn, almost as if the steering wheel was pushing back against the turn. When we got back home, I checked the power steering fluid...

Have a '98 K1500 Z71 off road, driving down the road it's usually fine sometimes has a hard spot. At idle sitting still it has very hard steering. Not sure if it's the pump, or a pressure relief, or my steering box. What should I check first for diagnosis?

I have a 2004 Sierra Z71 that is my baby. It has 112k on it and I have used synthetic since day 1. I just did my regular oil change today and when crawling under the truck I noticed some spots that were wet from new oil. One around the drain plug (I figure the plus is just old) the other one(s)...