dump bed was removed but the tank and pump on the transmission was left behind, how do i remove the pump but not leave the trans open do they make a plate that bolts in or something?

dana 70 rear end, what diff fluid should i be putting in it got one side of the brakes and new stainless flex line brake lines in and its working pretty nice

 

That is likely just the PTO that was left behind on the trans, not the actual pump for the dump hoist. No harm in letting it on there but if you want it off just un bolt it and install a flat cover plate. You could make one or get one off of an old four speed in the junk yard.