Loss of Power Steering while turning right

[ncscdmax]

I have a 2015 Silverado 2500HD with duramax and I am running into a situation where I lose power steering intermittently. It only happens when traveling at low speeds and turning right, when I let pressure off the wheel and then continue the turn it comes back but is quite dangerous when it happens. Sometimes it happens once a week and sometimes it happens multiple times a day, it’s hard to replicate so I am having trouble getting a dealer to diagnose. I have searched all over the internet and found where other people have a similar issue but I haven’t found where anyone said the fix. Need some help before I resort to trading it in. 

[davester]

fluid is at a good level, and has been flushed in the last year or two?

[ncscdmax]

I had the fluid flushed about 2 months ago, I checked the fluid again last night and it is still the same. The dealerships idea is to just start replacing parts but with the truck having 120,000 miles it is not covered under warranty and I don't want to "just start replacing parts" when they have no idea which part is actually failing.