97 c-5 seats move froward about 2 inches when braking, what causes this? Its almost like the seats are not locking in place.

if you have power seats then move seats back as far they go and then every inch or so violently pull them forward (to mimic the action of braking) and determine if its happening at the same spot if so then there may be a problem with a particular place in the track of the seat. if its happening no matter where it is then there is a possible problem with the electrical component, it will informative if its both seats at the same place of just one seat at one place and not the other.