well i'm sure someone may have already told you but just incase. this is most likly a normal thing. due to the hydro-boost brake system. this system includes the p/s system. there for has a direct effect to each other. By dry steering (which is not good on anything on the rig!) and the brake on the pressure is too great for the p/s release valve. Thus opening the valve making the assist from the power steering pump low if at all. As for the sudden un-binding when you release the brakes, that the rotors and steering system releaving all the force you just applied now that the wheels can rotate. Hope this helps
