Been working on friends 1970 Hemi Challenger repairing different items for over 20 years. He has had it for almost 40 years. 38,000 miles original car. Brings car over because it wont stop very well. I replaced front pads,calipers, and rotors. replaced rear wheel cylinders and shoes. When I went to bleed system,RF caliper wouldn't bleed. Found rubber hyd hose collapsed inside. Replaced all 3 rubber hoses. All wheels bleed fine. While in it, I suggest replace anything rubber. Bought new master cylinder and sent booster out to get rebuilt. When I open bleeders with helper pushing brake pedal, it goes all the way to floor. that's good. When done bleeding system it has high, hard pedal. But when road testing it, the car slowly stops even when standing hard on pedal. pedal goes down about and inch and is rock hard just like you but a 2x4 under the pedal. When put in reverse and standing hard on the pedal, car will slowly creep backward. So far everything in the brake system has been replaced except the 2 brass safety valves under the master cyl. I just ordered both new, will come next week. What am I missing?? Will the safety valves do something like that? Need ideas! thanks ahead, Jim