i know its been a while but i have been having a mare with the exhaust manifold but now thats sorted i thought i would change the proportioning valve, and that seems to have made no differenc either which annoys me a bit as it was a cnut to do!!
the only things the same now are the brake pipes the rear calipers and the servo, i dont think its the servo as that really only gives you pedal assist so it leave the pipes and the rear calipers, neither of which i can see causing the problem either so i am clueless now