My 1.8 Picasso Exclusive has suddenly developed a problem with the power steering. It was fine on the way to the shops, then not working suddenly on the way back. The fluid level was a bit low so this has now been topped up. I believe the auxiliary drive belt is ok as the air-con is still working, and this is driven with the same belt. Before I commit myself to a new pump does anyone know if there is an easy way to check this, as I don't want to have to change it and then find the problem is not fixed. Could anything else be causing this, if so how can I check?