Some points that helps for several bleeding problems:
- Take the front caliper a part with a spacer with thickness of the brake disks and move them during bleeding (had this problem on calipers where the bleeding screw is not exactly on the top of the caliper - maybe because they are from other car / mounting position)
- I use a PIN to fix residual pressure valve
- Take the drum brake shoes completely out (till the wheels could no more spin) and bleed. Than put them back to normal position (this helps to fill the cylinder in retracted position)
