I would try flushing the pump out (blowing it out) and giving it a good clean up. There should be 4 bolts on top, undo those and you should be able to see a few of the inside components. Don't clean it out with water as it may cause water stains to build up clogging up your pump. Try using more steering fluid (I know it's a waste but worth a shot). Quick question. Does it make a grinding droning noise when you steer?