'Stiff' section of steering when the cars first started?

[VolksKid83]

My 91 Passat has started a weird fault, its intermittent but seems to be happening alot more currently!

When the car has been left overnight or longer, it can have a 'stiff' section of steering, like its turned into a manual rack. Basically, i start the car and drive 150 yards to the end of my road to do a 3 point turn, turning the steering wheel it can be fine, then suddenly stiff for 1/4 of a turn of the steering wheel or around that. Then it will suddenly be perfect, and back to normal!?

The fluid is up to the max, a good six months ago the level dropped way below the min (but still showing a level in the reservoir), i bought the correct fluid and topped up, and it hasn't dropped since. It looks like somethings starting to go, so is it the pump or rack? Its done 204k now.

Cheers guys!