Spongy brakes, 914-4 brakes won't firm up??! Options

[Gearren]

I've had it! I have done everything to the brakes on my car, and I can't seem to get them to stop the car with authority. Best I get is a reluctant coast to a stop. Hardly suitable for street use! I have owned the 73 2.0 since new, and have kept it in the garage since 85. Brakes have always been weak, so as I starterd on the quest to revive the car, the brakes were top on the list. I have rebuilt both front and rear calipers, turned the rotors, new pads, new M/C (17mm), bled the m/c, bled the prop valve, and bled the system at least 10 times! I still have weak/spongy brakes! I want to keep the car stock, however I am tempted to remove the prop valve to see if it is the culprit. Any ideas or suggestions would be appreciated??

[Gearren]

I guess my plan of attack is to readjust the venting clearance to .004 and see if that helps/solves the problem. Then I will replace the SS lines with newer ones, and switch the fluid at that time to Dot 4 using a pressure bleeder and see what happens. If I'm still not right, I guess a replacement prop valve would be the next logical step, then a "T" fitting last. I figure 10 gallons of fluid ought to see me through this process!

For Eric_Shea, How much would you be interested in letting go of one of the prop valves and the "T" fitting?

Back in 83 I garaged my car, because I played hell trying to find parts and support in this part of the country. Things are sure looking up! Thanks for all the help! I'll keep you posted...Mike