There are 2 kinds of parking brakes on a 1 1/2 ton. One has a block inside a drum that sort of covers the u Joint right behind the trans. Another kind is a band which has frictional material around a drum on the back of the transmission. I'm not sure what type was used on a 45, but either one of them can rust to the drum after long periods of being set. If you have frictional material inside the drum it is the type we used to call Dou-grip. A am assuming the parking brake is on the back of the transmission and has a lever next to the gear shift.