Just to add my two cents, usually if it's a fire truck, pumper, it will most likely not have the parking brake on the drive shaft since the pump is driving by the drive shaft. On a 4 speed, most likely put the trany in 3rd, activate the transfer case (Wich uncouple the rear diff from the drive shaft) and pump water. If parking brake would have been installed behind the transmission, pumping water would have be impossible, and or parking brake totally inoperative when pump is engaged. Mounted on the front of the diff would work, but never seen it before. All this unless it is a front engine crank drive pump
Here in Canada, if it was ordered to be a fire truck it would have been most likely a maple leaf 3 ton, a rebadged GMC.... With the 6 bolts rims.
J. F.
