bfr812

I had the same problem on my 73 240z. My brake fluid had somehow been contaminated while in storage for 20years. I could bleed the brakes just fine but as soon as they heated up they would drag to the point of lock up. I finally pulled the master there was gel in it as well as in the booster. i replaced the master and cleaned the booster and then flushed the system. Good as new!! clean the mixing valve while you're at it. (NOTE: DON'T PULL THE ROD OUT OF THE BOOSTER. once it's back together adjust the rod from inside. look for posts on this. Good luck! B