The past couple of days the water temp had been hitting 100 degrees on my drive to work. So today I try and drive it to Kidderminster, driving it a bit hard as I've just fixed the other problems and felt like it. :P
Didn't get very far before the temp hit nearly 120 degrees and I had to pull over. The expansion tank looked like it was going to explode and the entire tank eventually flowed out through the overflow hole.
I am guessing my water pump is fooked? The AA man did a pressure test and it was holding pressure OK. He filled it up with water and followed us home, driving at 20 mph. Luckily the temp stayed at 90 degrees.