are your brake hoses the original rubber lines if so I have seen them start to come apart on the inside and not let all the pressure off
may be something to check


70 duster full chassis super pro 416 CNC Indybrock heads 727 w/brake

best so far 1.212 60 6.219 in 1/8 at 110.88 9.768 at 137.81 1/4