Offroading/Power Steering Leakage

I've always wondered in my own mind the damages that could be caused when offroading and turning the wheels that may in a way stress the system. My tie rod boot was looking a little oily for some time and I never thought much of it until "power steering" crossed my mind the other day. It's not something I am accustomed to checking. Well, it wasn't bad. I was at the MIN mark so topped it off with Valvoline up to the MAX. Truck has 90k on it.

Question is, is that leakage possibly a situation where there is leakage only when there is a lot of pressure on the seals (offroading) or would it probably be a constant slow leak?

(I don't know much about power steering)

 

dont have a real answer for you other than ive got 224,000kms on my 08 and ive had the oily look on my tie rod boots since about 40,000kms. havent had an issue yet.