I have only seen one other mk1 Clio with this problem.
Basically, was driving round a corner and thought the car was understeering as the steering went so light. We are talking car jacked up at the front with engine running light Infact, the PAS is working so hard that is you set the steering to central when stationary and tugg the steering wheel right then let go, it will run around to pretty much full lock on it's own! The pump sounds like it's labouring constantly unless steering is central and central steering play in the rack has occured when engine is off.
the French, they love giving us something to do don't they :D