PULLING UP AFTER A FENCE! If your horse brakes ...

If your horse brakes regularly after a fence and he tends to rush around a course of jumps - pull him up immediately after the fence. This should start teaching him to come back to you after each jump.

Set up a course of fences with fair distances between each jump and practice coming to a halt within a few strides of each jump, then accelerating again towards the next. Keep the fences small to start with to build your confidence levels.
Schooling your horse on the flat is a great way to him to get him listening to you and, ultimately, improve his brakes.