jason i think i might be able to shed some light, if you check through all the reciepts etc, i think it had new brake pipes etc for its mot in march, im wondering if one of the unions where they fit to the bulk head has come loose??? i think this is where the problem must be as you describe 'smoke' this must be where when you press the brake pedal a spray of brake fluid its going onto the hot exhaust manifold, hence the smoke.
hopefully it will be a case of tightening it up etc, topping up the fluid and then bleeding the brakes!!!
Gaz