are you -SURE- there is no brake for the foot brake? this sure sounds like the brake linkage is adjusted so that the foot brake switch is not releasing.
my memory says this unit should have a brake switch mounted under the floor pan and kind of under some of the linkage to the brake master cylinder, and that this unit's brake switch has a tendency to brake off the roller actuation lever, which if I remember this unit correctly, is an external to the switch lever that is held on with the same 2 screws that hold the switch to the linkage (although someone could have fitted a switch with the roller lever built into the switch).