The Stovebolt Site Forums The Shop Area Driveline Brake bleeding trouble and Residual pressure valves

Make sure your residual valves are going in right direction. pressure should be held on brake side.
They are required when master is below the brake cylinders in drums or disc brakes to keep the flow from going back to the master.
It should bleed with you just opening the bleeder and no cap on the remote reservoir in the engine bay. (i have this system as well).

I found my issue to be a small leak in the lines and brake cylinder causing the leak down and air getting into system.

In theory you would not need them with the remote fill way above. But they are nice to keep the cups closed and tight on the drum cylinders to keep air from bleeding back in.