Hi all, my parking brake is still not engaging and wondering if I need new rear calipers. Have completed the following so far: First, tried to adjust cables at the handle as recommended. Took the adjustment nut all the way down, both tires still spin. Physically observed parking brake springs working at the wheels but thought maybe cables were still stretched. Second, have replaced both cables and adjusted but still both wheels spin when e brake engaged. Have tried to adjust to full nut depth, no change. Spring levers working at wheels but nothing. Cannot see any other manual adjustment that I can make at caliper. Is there an internal mech. in the caliper that could be shot on both? Not sure what to do now except put on new calipers?