Brakes for a horse which doesn't take a contact?

[nicnag]

This is a bit of a complicated one. My big lad (grey one in my sig) is a generally well mannered and pleasant horse to ride. My one issue with him is he is difficult to feel a contact with. I ride in a plain eggbutt snaffle and cavesson noseband, he is easy to ride off your leg and will come into an outline but you still feel a bit like you don't really have any contact with his mouth, he doesn't really back off but he won't take it up either. My issue with him is that he has a little habit of ' travelling' faster than I'd like after jumps and after tonights episode (see post below) I'm not sure how to go about sorting this out? He's 19 so not a spring chicken. He can gather speed without fighting your contact at all!
any suggestions welcome!

 

[digitalangel]

my boy is similar- after jumps i really stiffen my seat and sit up and use half-halts