I installed a SSBC rear disc conversion on my chevelle. Which it had all around drum brakes but i decided to go all around disc which i still have the drum brake proportining valve on the car. So when i went to bleed my brakes I started out first to bench bleed the master cylinder on the vise stand fluid ran threw the plastic lines no air bubbles. Master Cyclinder full of fluid i installed it on the car and started to bleed my front the front brakes bleed fine. I went to the rear brakes using a one man brake bleeding kit. Just like i did on the front But was not getting no fluid to the rear. So im thinking the portioning valve might be closed and not allowing fluid to get pass it. So i took off the line at the portionting valve and no fluid in the line at all so i took off the line at the master cylinder and no fluid was not even coming out the master cyclinder at all so started to pump the brakes and no fluid shot out of the rear line port on the master cylinder at all. So i tried it on the front line port and fluid shot all the way across my garage so im thinking it was a bad master cyclinder. So i Purchased another master cylinder and it did the same thing can anyone help me on this problem. Im really lost as what could be causing this is it my method of bleeding the master cylinder.

A thought that comes to mind is to check the length of the rod from brake pedal to the boster to theh master cyl. Did you use their booster also? Do you have multiple mount holes or an adjustment for the rod? I am not familiar with the SSBC system, but it just seems that if you bench bled successfully, then you got fluid out ... Once mounted, you get no fluid out. I would suspect that the problem lies somewhere in the pedal rod properly engaging the mast cyl.

Not the problem, but this is surely not correct?

which i still have the drum brake proportining valve on the carIf you are too agressive bench bleeding the master you will get the inner plunger stuck forward.

There are two plungers inside the master that move. You have to be careful to only push the cup 1/2" or so to bleed the master. Push it too far before it fills and you have the EXACT same problem.

Hence two masters that do the same thing.

So, either replace it again, and be more cautious bench bleeding it, or take it apart and clean it, then rebench bleed it.

What does SSBC reccommend for the proportioning valve?

Are you using an all-disc master?

Why are you not calling them?

If I spent big $$ on brakes, I would be calling them first.