Dave
Thanks, From what I was told by the previous and 2nd owner the truck was originally owned by a vending machine dealer so the tailgate would be as old as you say. The pump does not seem to have a valve as you described only the globe valve and electric switch as seen in 2nd photo. The solenoid is under the hood and power is turned on by a key switch on the dash. I need to look at this a little more,get some fresh fluid in there and maybe add a valve like you described. I attached 2 photos of the pump
Ed
pump pics
