Steering Box & PAS Pump Problems

I have a 200tdi 90. I had the PAS pump fail about 3 months ago, looks like the baring went. Replaced that with a new one. Kept the old belt because it looked fine and was too lazy to get a new one.

Driving home last night and I hear a couple of belt squeals. At first I thought it was the alternator belt because the steering felt fine and I was diving on a straight road at about 38mph. A few seconds later I hear lots of squealing and feel a shudder on the steering wheel followed by loads of smoke and the smell of burning rubber. I pull over feeling surging on the wheel.

I look underneath. The belt has turned over onto it's side but isn't shredded. I notice the drop arm is covered in PAS fluid, not dripping but wet. I checked the fluid reservoir and it looked like it had only dropped about 5mm. The steering box is above the area where the drop arm connects.

I am now wondering what could of caused this? Can a failing steering box do this (considering the pump is new)? What can make the belt flip over? It's drove 3 months fine on and off road. Obviously because of the leak I will now look at replacing the steering box.

don't know what has caused your problems sorry, but where's the best place to get a new defender 200tdi steering pump?

The belt may have come off if the pulleys aren't in line or are damaged.
Some people reckon a capful of dot 3 or 4 in the steering fluid stops small leaks as it slightly expands the rubber seals. Havn't tried this personally but am going to this weekend. (steering box is shagged anyway)
harry