A few years ago I installed a CPP front disc brake conversion kit on my 56 3100. Last week I suddenly began losing pedal; I thought I had a bad wheel cylinder on the rear. Long story short, the provided proportioning / combination valve had sprung a colossal leak. The fitting in which the rear brake line goes had an orifice with a small rubber plug in it held in place by a pressed in star washer. The fitting on the replacement valve i ordered is solid and doesn’t have this orifice (although replacement valves with the orifice are available).
Does anyone know what is the function of this orifice and what does it mean when it sees enough pressure to rupture the plug or push it out? I already attended Google-U and learned nothing.
