it has become apparent that if i apply brakes after i have done full throttle (and taken it over 4000 revs) my brake pedal goes hard (looses its vacuum) for about 1 second, then back to normal, normal or not normal? its not a usual thing to notice, the only way to really find out is to go full throttle in 1st gear to 6000 revs then try to emergency stop, doesnt really work, normal driving its fine, only when really going for it then suddenly braking which is not something anyone would do often, if at all.