help centering a brake combination valve

[jeff1]

Hi all Need help centering a brake combination valve. Car has front disc/rear drum. Poor braking from rear brakes. Tried bleeding with pressure bleeder/old school pump the pedal/ and gravity flow method. Still no pressure at rear brakes. Feel like the blockage is in the combination valve [new]. i think I have recentered the valve but keep screwing it up trying to bleed system. I have a good hard pedal but with car in gear the rears continue to turn. Have pressure going into input side of valve but nothing on the pressure out to the rears. Thanks.

 

[67Dart273]

There used to be a tool for those, you removed the switch and screwed in the tool and it locked the valve centered for bleeding.