As per thread title....when i turn right, even slightly, the steering makes a large hissing sound but when i turn left its quite and only hisses @ full lock in a car park etc.

I will add, theres some noise coming from the power steering pulley on cold starts like a worn bearing.

Can anyone shed some knowledge on the reason for the excessive hissing on right hand turns?

Is the hiss you hear on right lock the same as the one you hear when on full left lock? Is the steering heavy on right turns?

If so, you may have a bit for debris caught in the relief port of the right hand side or a seal could be damaged in the rack.

Best bet would be to take to a power steering specialist about the fauly you have told us and be very exact about the description.

mate might be the pump itself they are very touchy apparently

yes the noise is the same for 'light' right turn to a 'full lock' left turn

This debris theory, how can i check for this? .... sorry not very power steering savy