Got the truck back together a while ago ( 1965 Chevy C60 two speed corporate rear and 292Ci with SM420 4 speed). TWO questions in one

1- I've got the PTO seals and gaskets I need. Is there anything I need to be careful of when i remove the unit from the side of the SM420? Never done a PTO before and this thing leaks like crazy.

2- rear brakes are getting hot and are to be sticking. I drove if with half a load of sunflowers to the farm i sold them to and when i got back the drums were 400F WAY TO HOT in my opinion. The shoes got relined and the drums were scuffed "clean" springs were in good shape when reused. I've got the adjusters backed all the way off now ( they are not even touching the shoes). Guessing I've got a groove or something that the shoes are stuck in or its not relieving the pressure back to the system. Anyone have any testing that I have not thought of. Could the Hydrovac be holding pressure to the rears? The front are not even warm to the touch on a quick 1/2 mile trek down the road.

1965 Chevy C60 Grain Truck