I've got a 78 c20 with the full floating rear axle that you have to pull the axles out to take the rotor off. Well, my back brakes aren't working I've checked the hydraulics and know the pads/wheel cyliners/hoses are good because I replaced they last summer. This past week I replaced the Master and booster, no air in the lines. I thought maybe they were just out of adjustment but when I go to the backing plate there's no hole to adjust them. WTH? Anyway, that's why I'm here hope someone can help me out.