1970 Rear Hold-off Valve

[gronlit]

Has anyone else had trouble with the valve pictured below?  1970 with the separate front disc holdoff valve hanging off of the booster, a distribution block near driver's footboard, and then this valve by the rear cross member.  Everything was new in the system except the calipers which were rebuilt. 

I had a horrible time bleeding the rear brakes.  I tried the pump-up and hold method with the brake pedal, a vacuum pump, and tried gravity bleed by just cracked the rear bleeders and let it sit for days...none of those methods got brake fluid to bleed from the back.   I eventually got a pressure bleeder to pressurize the master and was then able to get brake fluid to bleed from the rear.  After bleeding the system this way I jacked up the back end, put it in neutral but i could not get the rear brakes to hold the wheels from being able to be rotated by hand, no matter how we pressed on the pedal.

I ended up pulling the valve piston and spring out of the rear holdoff valve so now its just a distribution block and now the rear brakes work.  I'm not sure if the valve was defective or if I did something wrong somewhere else in the brake system or with bleeding.

[Dtret]

I haven’t got that far on my 70 yet, I’ll let you know in a few years ( lol) , but I do know both the valves were eliminated in 71/72. I wonder why?