767 nose wheel steering failure?

[axle61]

Can someone tell me what happens if a hydraulic failure in the nose wheel steering system occurs?

Is there some sort of safety valve that allows it to free castor, or is limited deflection available?

Or is there no movement possible at all?

Thankyou in advance

[skyhawk1]

Depending on the failure. I would say no movement at all as fluid is trapped in the actuators.
The system runs off the center system hydralics. In case of a loss of fluid - the system automaticly isolates the steering system so you have enough to steer with once you landed. But like I said it depends on the failure.