Xj40 power steering issues

Hi when turning to the right my xj40 steering wheel feels as if it wants to turn further than what I have turned it. It has a soft pulsating effect. This is most noticeable when going around a roundabout. The car also has a tendency to slightly oversteer to the right.absolutly no problems at all on the left lock. Has any body any ideas?.I should add that the previous owner had the power steering pump overhauled just before I got the car.

Ha,seems I may have solved the problem. The system was low on fluid and also had a lot of air bubbles when I topped it up. Went through the bleeding process as described in Hanes manual and now seems ok. Obviously when the pump was repaired the job wasn’t completed correctly. No sign of any leaks. Fingers crossed all ok.