I have a leak in my hydraulic tank and I think it may be cracked at the bracket. I'm going to pull so I can repair. I know the valves are in the tank. If I unbolt the manifolds on the outside so I can get it to lift out will the valves move in the tank. Not sure what's going to happen or the best way to pull it. Going to pump it out in the morning and hope it's light enough for me alone.
There should be a drain on the left side at the bottom. The tank/dash is heavy 200+ lbs? No way I would do it by hand. The seals around the control rods like to leak. You have to split the tank to change them. All the seals and gaskets just over $100 but it's a pita to do it. If your trans pump or converter are giving you issues now is the time to do that also since you have everything stripped to that point.
I'm not sure if a D is exactly the same but I pulled the hyd tank on my 6c without pulling the dash....think I took it out one side. Too heavy to lift by hand but you might be able to slide it out onto a loader. The shaft seals were leaking on mine.....seals had cut grooves in the lever shafts and at least one was unavailable from cat (and pricy if you can get them) so I just brazed them up and re-cut the seal area. If your throttle/decelerator linkage is worn it's a good time to fix it up since it's mounted under the tank....assuming it's like a 6c.
Even if your particular tank is found to be leaking at a different location I would strongly recommend replacing the seals for the control shafts plus any other work that might be required on the control linkages while you have it off the machine.
Come to think if it I have a entire 04X dash and tank on a pallet in the shed I would sell. I cant remember what prefix the tank is but if your interested I'll look.