I am having withdrawls from my beloved 1970 240z. My brake lights have been out and ive been trying to figure that out(not main problem) and realized my front calipers havent been working. i will add my proportioning valve is leaking slightly from right side, but the front calipers havent worked since i bought it. so i rebuilt and honed the cylinders and they work slightly. every time you press the pedal one side goes in and once that side hits the rotor, the other one gets some pressure, and so on. I had put a new 72 or 73 master cylinder and rebled the whole system after rebuilding one wheel cylinder which wasnt working well either. i'm stumped beside it being the leaky proportioning valve. the brake light went on for the leak after bleeding system first time. also now the pedal gained a little pressure again if you press it too hard you feel the pressure give and it slams to the floor. i decided to become part of the the community here to seek help and possible contribute with the small problems i have found and fixed that was not on any forum. If anyone would like to hear the ordeal of my brake , and help me, pm me.Thank you for your time.